1
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Li C, Liu L, Zhang Z, Zhang D, Yi S, Yang H, Fan Z. Anisotropy in Near-Spherical Colloidal Nanoparticles. ACS NANO 2023; 17:17873-17883. [PMID: 37682625 DOI: 10.1021/acsnano.3c03466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
Two major aspects of functional colloidal nanoparticles are their colloidal stability (dispersion) and controlled assembly of nanoparticles into ordered structures. Simplifying colloidal nanoparticles as isotropically interacting spheres is unsuitable for small nanoparticles capped with hydrocarbon chain ligands in which the ligand-ligand interaction plays a prominent role in the assembly processes. However, experimentally characterizing the ligand shell structure in solution presents significant challenges, and computer simulations yield divergent results without effective validation. Moreover, the connection between detailed information regarding ligand shell structures and interparticle interactions, in relation to the diverse dynamical behaviors of colloidal nanoparticles, remains poorly understood. In this study, we reveal the relationship between the ligand shell structures, interparticle interactions, and dynamical behaviors of few-nm-sized near-spherical nanoparticles capped with hydrocarbon chain ligands immersed in nonpolar solvents. Our study shows a transformation of the interparticle interactions from anisotropic attractions to isotropic repulsions as a result of the change in the ligand shell structures from order to disorder caused by varying temperature and other factors. The interplay between anisotropic attractions from ligand bundles and isotropic repulsions from disordered ligands dictates the nanoparticle dynamical behaviors of dispersion, uncontrolled aggregation, and controlled assembly.
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Affiliation(s)
- Chuncheng Li
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Lei Liu
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Ziyan Zhang
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Dan Zhang
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
- Department of Chemistry, Shanghai University, Shanghai 200444, P. R. China
| | - Shangzhao Yi
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Hongchao Yang
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Zhaochuan Fan
- Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei 230026, P. R. China
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2
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Rikanati L, Shema H, Ben-Tzvi T, Gross E. Nanoimaging of Facet-Dependent Adsorption, Diffusion, and Reactivity of Surface Ligands on Au Nanocrystals. NANO LETTERS 2023. [PMID: 37327381 DOI: 10.1021/acs.nanolett.3c00250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Analysis of the influence of dissimilar facets on the adsorption, stability, mobility, and reactivity of surface ligands is essential for designing ligand-coated nanocrystals with optimal functionality. Herein, para-nitrothiophenol and nitronaphthalene were chemisorbed and physisorbed, respectively, on Au nanocrystals, and the influence of different facets within a single Au nanocrystal on ligands properties were identified by IR nanospectroscopy measurements. Preferred adsorption was probed on (001) facets for both ligands, with a lower density on (111) facets. Exposure to reducing conditions led to nitro reduction and diffusion of both ligands toward the top (111) facet. Nitrothiophenol was characterized with a diffusivity higher than that of nitronaphthalene. Moreover, the strong thiol-Au interaction led to the diffusion of Au atoms and the formation of thiol-coated Au nanoparticles on the silicon surface. It is identified that the adsorption and reactivity of surface ligands were mainly influenced by the atomic properties of each facet, while diffusion was controlled by ligand-metal interactions.
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Affiliation(s)
- Lihi Rikanati
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University, Jerusalem 91904, Israel
| | - Hadar Shema
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University, Jerusalem 91904, Israel
| | - Tzipora Ben-Tzvi
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University, Jerusalem 91904, Israel
| | - Elad Gross
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University, Jerusalem 91904, Israel
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3
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Mahmood AU, Rizvi MH, Tracy JB, Yingling YG. Solvent Effects in Ligand Stripping Behavior of Colloidal Nanoparticles. ACS NANO 2023. [PMID: 37311219 DOI: 10.1021/acsnano.3c01313] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Inorganic colloidal nanoparticle (NP) properties can be tuned by stripping stabilizing ligands using a poor solvent. However, the mechanism behind ligand stripping is poorly understood, in part because in situ measurements of ligand stripping are challenging at the nanoscale. Here, we investigate ethanol solvent-mediated oleylamine ligand stripping from magnetite (Fe3O4) NPs in different compositions of ethanol/hexane mixtures using atomistic molecular dynamics (MD) simulations and thermogravimetric analysis (TGA). Our study elucidates a complex interplay of ethanol interactions with system components and indicates the existence of a threshold concentration of ∼34 vol % ethanol, above which ligand stripping saturates. Moreover, hydrogen bonding between ethanol and stripped ligands inhibits subsequent readsorption of the ligands on the NP surface. A proposed modification of the Langmuir isotherm explains the role of the enthalpy of mixing of the ligands and solvents on the ligand stripping mechanism. A good agreement between the MD predictions and TGA measurements of ligand stripping from Fe3O4 NPs validates the simulation observations. Our findings demonstrate that the ligand coverage of NPs can be controlled by using a poor solvent below the threshold concentration and highlight the importance of ligand-solvent interactions that modulate the properties of colloidal NPs. The study also provides an approach for a detailed in silico study of ligand stripping and exchange from colloidal NPs that are crucial for applications of NPs spanning self-assembly, optoelectronics, nanomedicine, and catalysis.
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Affiliation(s)
- Akhlak U Mahmood
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Mehedi H Rizvi
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Joseph B Tracy
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Yaroslava G Yingling
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
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4
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Hasan MR, Niebuur BJ, Siebrecht M, Kuttich B, Schweins R, Widmer-Cooper A, Kraus T. The Colloidal Stability of Apolar Nanoparticles in Solvent Mixtures. ACS NANO 2023; 17:9302-9312. [PMID: 37163685 DOI: 10.1021/acsnano.3c00812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Solvent engineering is a powerful and versatile method to tune colloidal stability. Here, we link the molecular structure of apolar ligand shells on gold nanoparticles with their colloidal stability in solvent mixtures. The agglomeration temperature of the particles was measured with small-angle X-ray scattering. It depended on solvent composition and changed linearly for hexane-hexadecane mixtures, but nonlinearly for cyclohexane-hexadecane and hexanol-hexadecane mixtures. Molecular dynamics (MD) simulations indicate that agglomeration is dominated by temperature-dependent ligand order in the alkane mixtures and that the temperature at which the ligand shell orders depends on the solvent composition near the ligands, which can differ substantially from the bulk composition. Small-angle neutron scattering confirmed that, at intermediate solvent compositions above the agglomeration temperature, the fraction of cyclohexane near the ligands was larger than in the bulk. The enrichment of cyclohexane near the ligands stabilized their disordered state, which, consequently, led to the experimentally observed nonlinear trend of the agglomeration temperature. In contrast, hexanol was depleted from the ligand shell at all temperatures. This again stabilized the disordered state. Furthermore, we found that agglomeration at high hexanol fractions was driven by a solvophobic effect that exceeded the influence of ligand order. The results show that strong nonlinearities in the colloidal stability of nanoparticle dispersions in solvent mixtures are directly linked to the molecular details of ligand-solvent and solvent-solvent interactions, which can be used to precisely tune stability.
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Affiliation(s)
- Mohammad Rashedul Hasan
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Bart-Jan Niebuur
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Martin Siebrecht
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Björn Kuttich
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Ralf Schweins
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble, France
| | - Asaph Widmer-Cooper
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
- The University of Sydney Nano Institute, University of Sydney, 66123 Sydney, New South Wales, Australia
| | - Tobias Kraus
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
- Colloid and Interface Chemistry, Saarland University, Campus D2 2, 66123 Saarbrücken, Germany
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5
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Petersen N, Girard M, Riedinger A, Valsson O. The Crucial Role of Solvation Forces in the Steric Stabilization of Nanoplatelets. NANO LETTERS 2022; 22:9847-9853. [PMID: 36493312 PMCID: PMC9801426 DOI: 10.1021/acs.nanolett.2c02848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 12/02/2022] [Indexed: 06/17/2023]
Abstract
The steric stability of inorganic colloidal particles in an apolar solvent is usually described in terms of the balance between three contributions: the van der Waals attraction, the free energy of mixing, and the ligand compression. However, in the case of nanoparticles, the discrete nature of the ligand shell and the solvent has to be taken into account. Cadmium selenide nanoplatelets are a special case. They combine a weak van der Waals attraction and a large facet to particle size ratio. We use coarse grained molecular dynamics simulations of nanoplatelets in octane to demonstrate that solvation forces are strong enough to induce the formation of nanoplatelet stacks and by that have a crucial impact on the steric stability. In particular, we demonstrate that for sufficiently large nanoplatelets, solvation forces are proportional to the interacting facet area, and their strength is intrinsically tied to the softness of the ligand shell.
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Affiliation(s)
- Nanning Petersen
- Max
Planck Institute for Polymer Research, Mainz D-55128, Germany
| | - Martin Girard
- Max
Planck Institute for Polymer Research, Mainz D-55128, Germany
| | | | - Omar Valsson
- Max
Planck Institute for Polymer Research, Mainz D-55128, Germany
- Department
of Chemistry, University of North Texas, Denton, Texas 76201, United States
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6
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Gentili D, Ori G. Reversible assembly of nanoparticles: theory, strategies and computational simulations. NANOSCALE 2022; 14:14385-14432. [PMID: 36169572 DOI: 10.1039/d2nr02640f] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The significant advances in synthesis and functionalization have enabled the preparation of high-quality nanoparticles that have found a plethora of successful applications. The unique physicochemical properties of nanoparticles can be manipulated through the control of size, shape, composition, and surface chemistry, but their technological application possibilities can be further expanded by exploiting the properties that emerge from their assembly. The ability to control the assembly of nanoparticles not only is required for many real technological applications, but allows the combination of the intrinsic properties of nanoparticles and opens the way to the exploitation of their complex interplay, giving access to collective properties. Significant advances and knowledge gained over the past few decades on nanoparticle assembly have made it possible to implement a growing number of strategies for reversible assembly of nanoparticles. In addition to being of interest for basic studies, such advances further broaden the range of applications and the possibility of developing innovative devices using nanoparticles. This review focuses on the reversible assembly of nanoparticles and includes the theoretical aspects related to the concept of reversibility, an up-to-date assessment of the experimental approaches applied to this field and the advanced computational schemes that offer key insights into the assembly mechanisms. We aim to provide readers with a comprehensive guide to address the challenges in assembling reversible nanoparticles and promote their applications.
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Affiliation(s)
- Denis Gentili
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Guido Ori
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Rue du Loess 23, F-67034 Strasbourg, France.
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7
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Zhang J, Li X, Liu Y, Feng J, Zhao J, Geng Y, Gao H, Wang T, Yang W, Jiang L, Wu Y. Confined Assembly of Colloidal Nanorod Superstructures by Locally Controlling Free-Volume Entropy in Nonequilibrium Fluids. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2202119. [PMID: 35522854 DOI: 10.1002/adma.202202119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/18/2022] [Indexed: 06/14/2023]
Abstract
Long-range-ordered structures of nanoparticles with controllable orientation have advantages in applications toward sensors, photoelectric conversion, and field-effect transistors. The assembly process of nanorods in colloidal systems undergoes a nonequilibrium process from dispersion to aggregation. A variety of assembly methods such as solvent volatilization, electromagnetic field induction, and photoinduction are restricted to suppress local perturbations during the nonequilibrium concentration of nanoparticles, which are adverse to controlling the orientation and order of assembled structures. Here, a confined assembly method is reported by locally controlling free-volume entropy in nonequilibrium fluids to fabricate microstructure arrays based on colloidal nanorods with controllable orientation and long-range order. The unique fluid dynamics of the liquid bridge is utilized to form a local region, where the free volume entropy reduction triggers assembly near the three-phase contact line (TPCL), allowing nanorods to assemble in 2D closest packing parallel to the TPCL for the maximum Gibbs free energy reduction. By manipulating the orientation of liquid flow, microstructures are assembled with programmable geometry, which sustains polarized photoluminescence and polarization-dependent photodetection. This confined assembly method opens up perspectives on assemblies of nanomaterials with controllable orientation and long-range order as a platform for multifunctional integrated devices.
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Affiliation(s)
- Jingyuan Zhang
- College of Chemistry, Jilin University, Changchun, Jilin, 130012, P. R. China
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Xiao Li
- Life and Health Research Institute, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin, 300384, P. R. China
| | - Yawei Liu
- Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jiangang Feng
- Department of Chemical and Biomolecular Sciences, National University of Singapore, Singapore, 117585, Singapore
| | - Jinjin Zhao
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yue Geng
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Hanfei Gao
- Ji Hua Laboratory, Foshan, Guangdong, 528200, P. R. China
| | - Tie Wang
- Life and Health Research Institute, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin, 300384, P. R. China
| | - Wensheng Yang
- College of Chemistry, Jilin University, Changchun, Jilin, 130012, P. R. China
| | - Lei Jiang
- College of Chemistry, Jilin University, Changchun, Jilin, 130012, P. R. China
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- Ji Hua Laboratory, Foshan, Guangdong, 528200, P. R. China
| | - Yuchen Wu
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- Ji Hua Laboratory, Foshan, Guangdong, 528200, P. R. China
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8
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Elimelech O, Aviv O, Oded M, Peng X, Harries D, Banin U. Entropy of Branching Out: Linear versus Branched Alkylthiols Ligands on CdSe Nanocrystals. ACS NANO 2022; 16:4308-4321. [PMID: 35157440 PMCID: PMC8945696 DOI: 10.1021/acsnano.1c10430] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Surface ligands of semiconductor nanocrystals (NCs) play key roles in determining their colloidal stability and physicochemical properties and are thus enablers also for the NCs flexible manipulation toward numerous applications. Attention is usually paid to the ligand binding group, while the impact of the ligand chain backbone structure is less discussed. Using isothermal titration calorimetry (ITC), we studied the effect of structural changes in the ligand chain on the thermodynamics of the exchange reaction for oleate coated CdSe NCs, comparing linear and branched alkylthiols. The investigated alkylthiol ligands differed in their backbone length, branching position, and branching group length. Compared to linear ligands, lower exothermicity and entropy loss were observed for an exchange with branched ligands, due to steric hindrance in ligand packing, thereby justifying their previous classification as "entropic ligands". Mean-field calculations for ligand binding demonstrate the contribution to the overall entropy originating from ligand conformational entropy, which is diminished upon binding mainly by packing of NC-bound ligands. Model calculations and the experimental ITC data both point to an interplay between the branching position and the backbone length in determining the entropic nature of the branched ligand. Our findings suggest that the most entropic ligand should be a short, branched ligand with short branching group located toward the middle of the ligand chain. The insights provided by this work also contribute to a future smarter NC surface design, which is an essential tool for their implementation in diverse applications.
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Affiliation(s)
- Orian Elimelech
- The
Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Omer Aviv
- The
Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Meirav Oded
- The
Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Xiaogang Peng
- Department
of Chemistry, Zhejiang University, Hangzhou 310027 P. R. China
| | - Daniel Harries
- The
Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The
Fritz Haber Center, The Hebrew University
of Jerusalem, Jerusalem 9190401, Israel
| | - Uri Banin
- The
Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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9
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Guillemeney L, Lermusiaux L, Landaburu G, Wagnon B, Abécassis B. Curvature and self-assembly of semi-conducting nanoplatelets. Commun Chem 2022; 5:7. [PMID: 36697722 PMCID: PMC9814859 DOI: 10.1038/s42004-021-00621-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/21/2021] [Indexed: 01/28/2023] Open
Abstract
Semi-conducting nanoplatelets are two-dimensional nanoparticles whose thickness is in the nanometer range and controlled at the atomic level. They have come up as a new category of nanomaterial with promising optical properties due to the efficient confinement of the exciton in the thickness direction. In this perspective, we first describe the various conformations of these 2D nanoparticles which display a variety of bent and curved geometries and present experimental evidences linking their curvature to the ligand-induced surface stress. We then focus on the assembly of nanoplatelets into superlattices to harness the particularly efficient energy transfer between them, and discuss different approaches that allow for directional control and positioning in large scale assemblies. We emphasize on the fundamental aspects of the assembly at the colloidal scale in which ligand-induced forces and kinetic effects play a dominant role. Finally, we highlight the collective properties that can be studied when a fine control over the assembly of nanoplatelets is achieved.
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Affiliation(s)
- Lilian Guillemeney
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Laurent Lermusiaux
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Guillaume Landaburu
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Benoit Wagnon
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Benjamin Abécassis
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
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10
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Liu Y, Klement M, Wang Y, Zhong Y, Zhu B, Chen J, Engel M, Ye X. Macromolecular Ligand Engineering for Programmable Nanoprism Assembly. J Am Chem Soc 2021; 143:16163-16172. [PMID: 34549954 DOI: 10.1021/jacs.1c07281] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ligands play a central role for the energetics and kinetics of nanocrystal assembly. Yet, the precise and simultaneous manipulation of ligands to dictate assembly outcome has proven difficult. Here, we present macromolecular ligand-engineering strategies to control, characterize, and model four molecular parameters of grafted polymer chains: chain length, chain dispersity, grafting density, and chain distribution. Direct ligand-exchange between nanoprisms and polymers functionalizes facets selectively and produces patchy nanocrystals. We develop a generalizable two-step ligand-exchange approach for the independent control of the two emergent brush parameters, brush thickness and brush softness. The resultant polymer-grafted prismatic nanocrystals with programmable ligand brushes self-assemble into thin-film superstructures of different wallpaper symmetries and faceted supracrystals. Our experiments are complemented by coarse-grained computer simulations of nanoprisms with directional, facet-specific interactions. This work paves the way for the precision synthesis of polymer-nanocrystal hybrid materials and enables the further refinement of theoretical models for particle brush materials.
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Affiliation(s)
- Yang Liu
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Marco Klement
- Institute for Multiscale Simulation, Interdisciplinary Center for Nanostructured Films, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Yi Wang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Yaxu Zhong
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Baixu Zhu
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Jun Chen
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Michael Engel
- Institute for Multiscale Simulation, Interdisciplinary Center for Nanostructured Films, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Xingchen Ye
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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11
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Importance of Surface Topography in Both Biological Activity and Catalysis of Nanomaterials: Can Catalysis by Design Guide Safe by Design? Int J Mol Sci 2021; 22:ijms22158347. [PMID: 34361117 PMCID: PMC8348784 DOI: 10.3390/ijms22158347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/07/2021] [Accepted: 06/15/2021] [Indexed: 12/28/2022] Open
Abstract
It is acknowledged that the physicochemical properties of nanomaterials (NMs) have an impact on their toxicity and, eventually, their pathogenicity. These properties may include the NMs’ surface chemical composition, size, shape, surface charge, surface area, and surface coating with ligands (which can carry different functional groups as well as proteins). Nanotopography, defined as the specific surface features at the nanoscopic scale, is not widely acknowledged as an important physicochemical property. It is known that the size and shape of NMs determine their nanotopography which, in turn, determines their surface area and their active sites. Nanotopography may also influence the extent of dissolution of NMs and their ability to adsorb atoms and molecules such as proteins. Consequently, the surface atoms (due to their nanotopography) can influence the orientation of proteins as well as their denaturation. However, although it is of great importance, the role of surface topography (nanotopography) in nanotoxicity is not much considered. Many of the issues that relate to nanotopography have much in common with the fundamental principles underlying classic catalysis. Although these were developed over many decades, there have been recent important and remarkable improvements in the development and study of catalysts. These have been brought about by new techniques that have allowed for study at the nanoscopic scale. Furthermore, the issue of quantum confinement by nanosized particles is now seen as an important issue in studying nanoparticles (NPs). In catalysis, the manipulation of a surface to create active surface sites that enhance interactions with external molecules and atoms has much in common with the interaction of NP surfaces with proteins, viruses, and bacteria with the same active surface sites of NMs. By reviewing the role that surface nanotopography plays in defining many of the NMs’ surface properties, it reveals the need for its consideration as an important physicochemical property in descriptive and predictive toxicology. Through the manipulation of surface topography, and by using principles developed in catalysis, it may also be possible to make safe-by-design NMs with a reduction of the surface properties which contribute to their toxicity.
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12
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Pansu B, Goldmann C, Constantin D, Impéror-Clerc M, Sadoc JF. Softness-driven complexity in supercrystals of gold nanoparticles. SOFT MATTER 2021; 17:6461-6469. [PMID: 34132715 DOI: 10.1039/d1sm00617g] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Many soft matter systems are composed of roughly spherical objects that can self-assemble in ordered structures. Unlike hard spheres, at high volume fraction these soft spheres adapt their shape to the local geometrical constraints and the question of space filling needs to be entirely revisited. Hydrophobically coated gold nanocrystals self-assemble in supercrystals and are good candidates to explore this question. When the soft coating is thin compared to the rigid core, a FCC structure is obtained, with a behaviour similar to that of hard spheres. In the opposite case, for a thick soft coating, a BCC structure is found instead. This paper focus on the intermediate region between these two classical structures. By varying the gold core radius R and the ligand fully extended length L, we establish a structure diagram based on a large experimental data set. The hexagonal Frank-Kasper C14 structure is observed for various values of R and L and can coexist with a FCC phase. Depending on the structure, values of the minimum thickness e of the ligand shell compared to L are different. These experimental results confirm that the C14 Frank-Kasper phase is a solution to the problem of filling the space with soft particles even with a rigid core and should help to establish pertinent models in order to predict the structures of the superlattices built by gold nanoparticles.
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Affiliation(s)
- Brigitte Pansu
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France.
| | - Claire Goldmann
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France.
| | - Doru Constantin
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France.
| | - Marianne Impéror-Clerc
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France.
| | - Jean-François Sadoc
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France.
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13
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Yan T, Fichthorn KA. Self-Assembly of a Linear Alkylamine Bilayer around a Cu Nanocrystal: Molecular Dynamics. J Phys Chem B 2021; 125:4178-4186. [PMID: 33872508 DOI: 10.1021/acs.jpcb.1c02043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Copper nanocrystals are often grown with the help of alkylamine capping agents, which direct the nanocrystal shape. However, the role of these molecules is still unclear. We characterized the assembly of aqueous tetradecylamine (TDA) around a Cu nanocrystal and found that TDA exhibits a temperature-dependent bilayer structure. The bilayer involves an inner layer, in which TDA binds to Cu via the amine group and tends to orient the alkyl tail perpendicular to the surface, and an outer layer whose structure depends on temperature. At low temperatures, alkylamines in the inner layer form bundles with no apparent relation to the crystal facets. Alkylamines in the outer layer tend to orient their long axes perpendicular to the Cu surfaces, with interdigitation into the inner layer. At high temperatures, alkylamines in the inner layer lose their bundle structure, and outer-layer alkylamines tend to orient themselves tangential to the Cu surfaces, forming a "web" above inner-layer TDA. TDA exhibits a rapid interlayer exchange at typical synthesis temperatures, consistent with experiment. The variety in the assemblies seen here and in other studies of alkanethiols around gold nanocrystals indicates a richness in the assemblies that can be achieved by modulating the interaction between the strongly binding end group and the surface.
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Affiliation(s)
- Tianyu Yan
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kristen A Fichthorn
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.,Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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14
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Fan Z, Zhang L, Di W, Li K, Li G, Sun D. Methyl-grafted silica nanoparticle stabilized water-in-oil Pickering emulsions with low-temperature stability. J Colloid Interface Sci 2021; 588:501-509. [PMID: 33434877 DOI: 10.1016/j.jcis.2020.12.095] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/09/2020] [Accepted: 12/24/2020] [Indexed: 11/16/2022]
Abstract
HYPOTHESIS The viscosity of water-in-oil Pickering emulsions may dramatically increase upon cooling. The solvation of the long-chain alkyl groups grafted on the particles stabilizer is the likely cause of the strong dependence of rheological property on temperature. Thus, we hypothesize that silica nanoparticles (NPs) grafted with short-chain alkyl groups can stabilize Pickering emulsions, yielding weakly temperature-dependent rheological property. EXPERIMENTS Using alkyl-grafted (methyl, octyl, and octadecyl) silica NPs as emulsifiers, the rheological properties and microstructure of the water-in-oil Pickering, as well as the solvation of the silica NPs, were studied using diffusing-wave spectroscopy microrheology measurements, confocal laser scanning microscopy, and low-field nuclear magnetic resonance measurements. FINDINGS The use of methyl- and octadecyl-grafted silica NPs, which have almost identical optimum contact angles, to stabilize emulsions dramatically reduced the effect of cooling on the viscosity. Moreover, the emulsions stabilized by these methyl-grafted silica NPs exhibited nearly constant rheological properties as the temperature decreased from 75 to 5 °C. The nearly constant rheological properties are attributed to the nearly constant solvation in this temperature range. These materials have potential applications in the cosmetics and petroleum industries.
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Affiliation(s)
- Zhe Fan
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China
| | - Li Zhang
- Qilu University of Technology (Shandong Academy of Sciences), Shandong Analysis and Test Centre, Jinan, Shandong 250014, PR China.
| | - Wenwen Di
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China
| | - Kuncheng Li
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China
| | - Gongrang Li
- Drilling Technology Research Institute, Shengli Petroleum Engineering Corporation Limited of SINOPEC, Dongying, Shandong 257017, PR China
| | - Dejun Sun
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China.
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15
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Shevchenko EV, Podsiadlo P, Wu X, Lee B, Rajh T, Morin R, Pelton M. Visualizing Heterogeneity of Monodisperse CdSe Nanocrystals by Their Assembly into Three-Dimensional Supercrystals. ACS NANO 2020; 14:14989-14998. [PMID: 33073574 DOI: 10.1021/acsnano.0c04864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We show that the self-assembly of monodisperse CdSe nanocrystals synthesized at lower temperature (∼310 °C) into three-dimensional supercrystals results in the formation of separate regions within the supercrystals that display photoluminescence at two distinctly different wavelengths. Specifically, the central portions of the supercrystals display photoluminescence and absorption in the orange region of the spectrum, around 585 nm, compared to the 575 nm photoluminescence maximum for the nanocrystals dispersed in toluene. Distinct domains on the surfaces and edges of the supercrystals, by contrast, display photoluminescence and absorption in the green region of the spectrum, around 570 nm. We attribute the different-colored domains to two subpopulations of NCs in the monodisperse ensemble: the nanocrystals in the "orange" regions are chemically stable, whereas the nanocrystals in the "green" regions are partially oxidized. The susceptibility of the "green" nanocrystals to oxidation indicates a lower coverage of capping molecules on these nanocrystals. We propose that the two subpopulations correspond to nanocrystals with different surfaces that we attribute to the polytypism of CdSe.
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Affiliation(s)
- Elena V Shevchenko
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Paul Podsiadlo
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
- ExxonMobil Research and Engineering Company, Fuels, Process & Optimization Technology Process Engineering Division, 22777 Springwoods Village, Parkway Spring, Texas 77389, United States
| | - Xiaohua Wu
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
- Mindray, Mindray Building, Hitech Industrial Park, Nanshan District, Shenzhen 518057, China
| | - Byeongdu Lee
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Tijana Rajh
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Rachel Morin
- Department of Physics, UMBC (University of Maryland, Baltimore County), 1000 Hilltop Circle, Baltimore, Maryland 20912, United States
| | - Matthew Pelton
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
- Department of Physics, UMBC (University of Maryland, Baltimore County), 1000 Hilltop Circle, Baltimore, Maryland 20912, United States
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16
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Asaduzzaman A, Runge K, Deymier P, Muralidharan K. Effect of Ligand Adsorption on the Electronic Properties of the PbS(100) Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13312-13319. [PMID: 33112623 DOI: 10.1021/acs.langmuir.0c02425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A first-principles density functional theory calculation was carried out to study the adsorption of acetic acid, methyl amine, methanethiol, and hydrogen iodide on the (100) surface of PbS. All four ligands are common capping agents used in colloidal PbS quantum dot-based photovoltaics. Interestingly, among the considered adsorbates, dissociative adsorption was energetically preferred for hydrogen iodide, while associative adsorption was favorable for the rest. Associative adsorption was driven by strong interactions between the electronegative elements (Y) in the respective ligands and the Pb surface atoms via Pb 6p-Y np bond hybridization (n represents the valence quantum number of the respective electronegative elements). Importantly, the adsorption of ligands altered the work function of PbS, with contrasting trends for associative (decrease in the work function) versus dissociative (increase in the work function) adsorption. The changes in the work function correlates well with a corresponding shift in the 5d level of surface Pb atoms. Other important observations include variations in the work function that linearly change with increasing the surface coverage of adsorbed ligands as well as with the strength of the adsorption of ligands.
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Affiliation(s)
- Abu Asaduzzaman
- School of Science, Engineering and Technology, Pennsylvania State University - Harrisburg, Middletown, Pennsylvania 17057, United States
| | - Keith Runge
- Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Pierre Deymier
- Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Krishna Muralidharan
- Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721, United States
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17
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Monego D, Kister T, Kirkwood N, Doblas D, Mulvaney P, Kraus T, Widmer-Cooper A. When Like Destabilizes Like: Inverted Solvent Effects in Apolar Nanoparticle Dispersions. ACS NANO 2020; 14:5278-5287. [PMID: 32298080 DOI: 10.1021/acsnano.9b03552] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We report on the colloidal stability of nanoparticles with alkanethiol shells in apolar solvents. Small-angle X-ray scattering and molecular dynamics simulations were used to characterize the interaction between nanoparticles in linear alkane solvents ranging from hexane to hexadecane, including 4 nm gold cores with hexadecanethiol shells and 6 nm cadmium selenide cores with octadecanethiol shells. We find that the agglomeration is enthalpically driven and that, contrary to what one would expect from classical colloid theory, the temperature at which the particles agglomerate increases with increasing solvent chain length. We demonstrate that the inverted trend correlates with the temperatures at which the ligands order in the different solvents and show that the inversion is due to a combination of enthalpic and entropic effects that enhance the stability of the ordered ligand state as the solvent length increases. We also explain why cyclohexane is a better solvent than hexadecane despite the two having very similar solvation parameters.
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Affiliation(s)
- Debora Monego
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
- The University of Sydney Nano Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Thomas Kister
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Nicholas Kirkwood
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - David Doblas
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Paul Mulvaney
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Tobias Kraus
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
- Colloid and Interface Chemistry, Saarland University, Campus D2 2, 66123 Saarbrücken, Germany
| | - Asaph Widmer-Cooper
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
- The University of Sydney Nano Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
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18
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Kim D, Lee DC. Surface Ligands as Permeation Barrier in the Growth and Assembly of Anisotropic Semiconductor Nanocrystals. J Phys Chem Lett 2020; 11:2647-2657. [PMID: 32175742 DOI: 10.1021/acs.jpclett.9b03052] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Because of the large surface-to-volume ratio of colloidal nanocrystals (NCs), surfactant molecules grafted at the NC surface play an important role in NC growth, interparticle interaction, processing, and application. For this reason, much progress has been made in understanding the surface chemistry of NCs along with the organic ligand shell, particularly in terms of grafted polar groups. However, most explanations of aliphatic counterparts are based on spherical NCs that usually have a dilute ligand layer. In anisotropic NCs such as nanorods and nanoplatelets, the linearly extended dimension results in a high-density aliphatic layer on the NC surface. Unlike spherical NCs, the compact organic shell could serve as a permeation membrane, effectively impeding a penetration of foreign molecules toward the NC surface. In this Perspective, we highlight the effects of ligand configuration on the properties of anisotropic NCs by exploring morphologies, assembled superstructures, and surface reaction of anisotropic NCs.
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Affiliation(s)
- Dahin Kim
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Doh C Lee
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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19
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Zha X, Travesset A. The hard sphere diameter of nanocrystals (nanoparticles). J Chem Phys 2020; 152:094502. [DOI: 10.1063/1.5132747] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Xun Zha
- Department of Physics and Astronomy, Ames, Iowa 50011, USA
| | - Alex Travesset
- Department of Physics and Astronomy and Ames Lab, Ames, Iowa 50011, USA
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20
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Balan AD, Olshansky JH, Horowitz Y, Han HL, O'Brien EA, Tang L, Somorjai GA, Alivisatos AP. Unsaturated Ligands Seed an Order to Disorder Transition in Mixed Ligand Shells of CdSe/CdS Quantum Dots. ACS NANO 2019; 13:13784-13796. [PMID: 31751115 DOI: 10.1021/acsnano.9b03054] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A phase transition within the ligand shell of core/shell quantum dots is studied in the prototypical system of colloidal CdSe/CdS quantum dots with a ligand shell composed of bound oleate (OA) and octadecylphosphonate (ODPA). The ligand shell composition is tuned using a ligand exchange procedure and quantified through proton NMR spectroscopy. Temperature-dependent photoluminescence spectroscopy reveals a signature of a phase transition within the organic ligand shell. Surprisingly, the ligand order to disorder phase transition triggers an abrupt increase in the photoluminescence quantum yield (PLQY) and full-width at half-maximum (FWHM) with increasing temperature. The temperature and width of the phase transition show a clear dependence on ligand shell composition, such that QDs with higher ODPA fractions have sharper phase transitions that occur at higher temperatures. In order to gain a molecular understanding of the changes in ligand ordering, Fourier transform infrared and vibrational sum frequency generation spectroscopies are performed. These measurements confirm that an order/disorder transition in the ligand shell tracks with the photoluminescence changes that accompany the ligand phase transition. The phase transition is simulated through a lattice model that suggests that the ligand shell is well-mixed and does not have completely segregated domains of OA and ODPA. Furthermore, we show that the unsaturated chains of OA seed disorder within the ligand shell.
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Affiliation(s)
- Arunima D Balan
- Material Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute , Berkeley , California 94720 , United States
| | - Jacob H Olshansky
- Material Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute , Berkeley , California 94720 , United States
| | - Yonatan Horowitz
- Material Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute , Berkeley , California 94720 , United States
| | - Hui-Ling Han
- Material Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute , Berkeley , California 94720 , United States
| | - Erin A O'Brien
- Material Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute , Berkeley , California 94720 , United States
| | | | - Gabor A Somorjai
- Material Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute , Berkeley , California 94720 , United States
| | - A Paul Alivisatos
- Material Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute , Berkeley , California 94720 , United States
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21
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Fan Z, Zhang L, Liu S, Luan L, Li G, Sun D. Mechanism of high temperature induced destabilization of nonpolar organoclay suspension. J Colloid Interface Sci 2019; 555:53-63. [PMID: 31376768 DOI: 10.1016/j.jcis.2019.07.072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 07/22/2019] [Accepted: 07/24/2019] [Indexed: 11/28/2022]
Abstract
HYPOTHESIS High temperatures can reduce the colloidal stability and rheological properties of nonpolar organoclay suspensions. The desorption of surfactants from organoclay has been proposed to explain this effect, but the mechanism remains unclear. In this work, it was hypothesized that the high-temperature-induced desorption of ion-exchanged surfactants is the main factor affecting the stabilization of suspensions. EXPERIMENTS Using the cationic surfactant dimethyldioctadecylammonium chloride (DODMAC) and Na-montmorillonite (Na-MMT), the high-temperature-induced reestablishment of the adsorption-desorption equilibrium of DODMAC in organoclay suspensions was studied. Thermogravimetric analysis combined with infrared spectroscopy and gas chromatography/mass spectrometry experiments were performed to determine the thermal decomposition products and, ultimately, infer the adsorption modes and locations of DODMAC on Na-MMT. Thermal analysis and rheology were utilized to demonstrate the high-temperature-induced desorption and transfer of DODMAC in organoclay suspensions. FINDINGS High temperatures induced the complete desorption of physically adsorbed DODMAC molecules from particle surfaces, the partial desorption of ion-exchanged dimethyldioctadecylammonium ions (DODMA+ ions) from particle surfaces, and the partial transfer of ion-exchanged DODMA+ ions from the surfaces to the interlayers. Importantly, desorption of ion-exchanged DODMA+ ions resulted in destabilization of the organoclay suspensions at high temperatures.
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Affiliation(s)
- Zhe Fan
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China
| | - Li Zhang
- Shandong Analysis and Test Centre, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250014, PR China.
| | - Shangying Liu
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China
| | - Lingyu Luan
- Shandong Analysis and Test Centre, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250014, PR China
| | - Gongrang Li
- Drilling Technology Research Institute, Shengli Petroleum Engineering Corporation Limited of SINOPEC, Dongying, Shandong 257017, PR China
| | - Dejun Sun
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, Shandong 250100, PR China.
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22
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Bronstein ND, Martinez MS, Kroupa DM, Vörös M, Lu H, Brawand NP, Nozik AJ, Sellinger A, Galli G, Beard MC. Designing Janus Ligand Shells on PbS Quantum Dots using Ligand-Ligand Cooperativity. ACS NANO 2019; 13:3839-3846. [PMID: 30855942 DOI: 10.1021/acsnano.9b00191] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present a combined experimental and theoretical study of ligand-ligand cooperativity during X-type carboxylate-to-carboxylate ligand exchange reactions on PbS quantum dot surfaces. We find that the ligand dipole moment (varied through changing the substituents on the benzene ring of cinnamic acid derivatives) impacts the ligand-exchange isotherms; in particular, ligands with large electron withdrawing character result in a sharper transition from an oleate-dominated ligand shell to a cinnamate-dominated ligand shell. We developed a two-dimensional lattice model to simulate the ligand-exchange isotherms that accounts for the difference in ligand binding energy as well as ligand-ligand cooperativity. Our model shows that ligands with larger ligand-ligand coupling energy exhibit sharper isotherms indicating an order-disorder phase transition. Finally, we developed an anisotropic Janus ligand shell by taking advantage of the ligand-ligand cooperative ligand exchanges. We monitored the Janus ligand shell using 19F nuclear magnetic resonance, showing that when the ligand-ligand coupling energy falls within the order region of the phase diagram, Janus ligand shells can be constructed.
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Affiliation(s)
- Noah D Bronstein
- Chemistry & Nanoscience Center, National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Marissa S Martinez
- Chemistry & Nanoscience Center, National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
- Department of Chemistry and Biochemistry , University of Colorado , Boulder , Colorado 80309 , United States
| | - Daniel M Kroupa
- Chemistry & Nanoscience Center, National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
- Department of Chemistry and Biochemistry , University of Colorado , Boulder , Colorado 80309 , United States
| | - Márton Vörös
- Materials Science Division , Argonne National Laboratory , Lemont , Illinois 60439 , United States
- Institute for Molecular Engineering, University of Chicago , Chicago , Illinois 60637 , United States
| | - Haipeng Lu
- Chemistry & Nanoscience Center, National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Nicholas P Brawand
- Institute for Molecular Engineering, University of Chicago , Chicago , Illinois 60637 , United States
| | - Arthur J Nozik
- Chemistry & Nanoscience Center, National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
- Department of Chemistry and Biochemistry , University of Colorado , Boulder , Colorado 80309 , United States
| | - Alan Sellinger
- Chemistry & Nanoscience Center, National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
- Department of Chemistry and Materials Science Program , Colorado School of Mines , Golden , Colorado 80401 , United States
| | - Giulia Galli
- Materials Science Division , Argonne National Laboratory , Lemont , Illinois 60439 , United States
- Institute for Molecular Engineering, University of Chicago , Chicago , Illinois 60637 , United States
- Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
| | - Matthew C Beard
- Chemistry & Nanoscience Center, National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
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23
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Fan Z, Grünwald M. Orientational Order in Self-Assembled Nanocrystal Superlattices. J Am Chem Soc 2019; 141:1980-1988. [DOI: 10.1021/jacs.8b10752] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Zhaochuan Fan
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Michael Grünwald
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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24
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Monego D, Kister T, Kirkwood N, Mulvaney P, Widmer-Cooper A, Kraus T. Colloidal Stability of Apolar Nanoparticles: Role of Ligand Length. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:12982-12989. [PMID: 30299970 DOI: 10.1021/acs.langmuir.8b02883] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Inorganic nanoparticle cores are often coated with organic ligands to render them dispersible in apolar solvents. However, the effect of the ligand shell on the colloidal stability of the overall hybrid particle is not fully understood. In particular, it is not known how the length of an apolar alkyl ligand chain affects the stability of a nanoparticle dispersion against agglomeration. Here, small-angle X-ray scattering and molecular dynamics simulations have been used to study the interactions between gold nanoparticles and between cadmium selenide nanoparticles passivated by alkanethiol ligands with 12-18 carbons in the solvent decane. We find that increasing the ligand length increases colloidal stability in the core-dominated regime but decreases it in the ligand-dominated regime. This unexpected inversion is connected to the transition from ligand-dominated to core-dominated agglomeration when the core diameter increases at constant ligand length. Our results provide a microscopic picture of the forces that determine the colloidal stability of apolar nanoparticles and explain why classical colloid theory fails.
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Affiliation(s)
- Debora Monego
- ARC Centre of Excellence in Exciton Science, School of Chemistry and The University of Sydney Nano Institute , University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Thomas Kister
- INM-Leibniz Institute for New Materials , Campus D2 2 , 66123 Saarbrücken , Germany
| | - Nicholas Kirkwood
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Paul Mulvaney
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Asaph Widmer-Cooper
- ARC Centre of Excellence in Exciton Science, School of Chemistry and The University of Sydney Nano Institute , University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Tobias Kraus
- INM-Leibniz Institute for New Materials , Campus D2 2 , 66123 Saarbrücken , Germany
- Colloid and Interface Chemistry , Saarland University , Campus D2 2 , 66123 Saarbrücken , Germany
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25
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Ni B, Shi Y, Wang X. The Sub-Nanometer Scale as a New Focus in Nanoscience. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802031. [PMID: 30039573 DOI: 10.1002/adma.201802031] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Indexed: 06/08/2023]
Abstract
Size is one of the central issues in nanoscience. The practical meaning of the term "sub-nanometric material (SNM)" requires two aspects: (1) its size should be at the atomic level; (2) it shows unique (size-related) properties compared to its nano-counterparts with larger sizes. Here, SNMs in the form of wires (SNWs) and the unique properties arising from their special size are reviewed. First, their polymer-like behavior, including rheological behavior and self-assembly, is dicussed. Their origins may stem from the special size and the ligands around the wire. Even a slight increase in diameter would risk the polymer-like behavior. Meanwhile, the ligands on SNWs are proportional to the inorganic entity at this scale. Consequently, surface ligands should have a profound impact on the properties, like catalysis, self-assembly, optics, etc. To reveal more potential applications, their applications in energy conversion are comprehensively reviewed. To some extent, characterization can greatly influence the way things are observed. Thus, some appropriate characterization techniques are briefly introduced. Finally, another emerging part of SNWs (atomic chain material) is briefly introduced. It is hoped that this review can provide new insights to this special scale.
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Affiliation(s)
- Bing Ni
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yuang Shi
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Xun Wang
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, China
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26
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Zhu H, Fan Z, Yuan Y, Wilson MA, Hills-Kimball K, Wei Z, He J, Li R, Grünwald M, Chen O. Self-Assembly of Quantum Dot-Gold Heterodimer Nanocrystals with Orientational Order. NANO LETTERS 2018; 18:5049-5056. [PMID: 29989818 DOI: 10.1021/acs.nanolett.8b01860] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The self-assembly of nanocrystals into ordered superlattices is a powerful strategy for the production of functional nanomaterials. The assembly of well-ordered target structures, however, requires control over the building blocks' size and shape as well as their interactions. While nanocrystals with homogeneous composition are now routinely synthesized with high precision and assembled into various ordered structures, high-quality multicomponent nanocrystals and their ordered assemblies are rarely reported. In this paper, we demonstrate the synthesis of quantum dot-gold (QD-Au) heterodimers. These heterodimers possess a uniform shape and narrow size distribution and are capped with oleylamine and dodecyltrimethylammonium bromide (DTAB). Assembly of the heterodimers results in a superlattice with long-range orientational alignment of dimers. Using synchrotron-based X-ray measurements, we characterize the complex superstructure formed from the dimers. Molecular dynamics simulations of a coarse-grained model suggest that anisotropic interactions between the quantum dot and gold components of the dimer drive superlattice formation. The high degree of orientational order demonstrated in this work is a potential route to nanomaterials with useful optoelectronic properties.
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Affiliation(s)
- Hua Zhu
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Zhaochuan Fan
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Yucheng Yuan
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Mitchell A Wilson
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Katie Hills-Kimball
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Zichao Wei
- Department of Chemistry , University of Connecticut , Storrs , Connecticut 06269 , United States
| | - Jie He
- Department of Chemistry , University of Connecticut , Storrs , Connecticut 06269 , United States
| | - Ruipeng Li
- National Synchrotron Light Source II , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Michael Grünwald
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Ou Chen
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
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27
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Burian M, Karner C, Yarema M, Heiss W, Amenitsch H, Dellago C, Lechner RT. A Shape-Induced Orientation Phase within 3D Nanocrystal Solids. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802078. [PMID: 29944182 DOI: 10.1002/adma.201802078] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Indexed: 05/12/2023]
Abstract
When nanocrystals self assemble into ordered superstructures they form functional solids that may inherit the electronical properties of the single nanocrystals. To what extent these properties are enhanced depends on the positional and orientational order of the nanocrystals within the superstructure. Here, the formation of micrometer-sized free-standing supercrystals of faceted 20 nm Bi nanocrystals is investigated. The self-assembly process, induced by nonsolvent into solvent diffusion, is probed in situ by synchrotron X-ray scattering. The diffusion-gradient is identified as the critical parameter for controlling the supercrystal-structure as well as the alignment of the supercrystals with respect to the substrate. Monte Carlo simulations confirm the positional order of the nanocrystals within these superstructures and reveal a unique orientation phase: the nanocrystal shape, determined by the atomic Bi crystal structure, induces a total of 6 global orientations based on facet-to-facet alignment. This parallel alignment of facets is a prerequisite for optimized electronic and optical properties within designed nanocrystal solids.
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Affiliation(s)
- Max Burian
- Institute of Physics, Montanuniversitaet Leoben, 8700, Leoben, Austria
- Institute for Inorganic Chemistry, Graz University of Technology, 8010, Graz, Austria
| | - Carina Karner
- Faculty of Physics, University of Vienna, 1090, Wien, Austria
| | - Maksym Yarema
- Laboratory for Nanoelectronics, Department of Electrical Engineering and Information Technology, ETH Zurich, 8092, Zurich, Switzerland
| | - Wolfgang Heiss
- Materials Science Department (Materials for Electronics and Energy Technology), Friedrich-Alexander Universität Erlangen-Nürnberg, Energy Campus Nürnberg, Nürnberg, 90429, Germany
| | - Heinz Amenitsch
- Institute for Inorganic Chemistry, Graz University of Technology, 8010, Graz, Austria
| | | | - Rainer T Lechner
- Institute of Physics, Montanuniversitaet Leoben, 8700, Leoben, Austria
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28
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Bouju X, Duguet É, Gauffre F, Henry CR, Kahn ML, Mélinon P, Ravaine S. Nonisotropic Self-Assembly of Nanoparticles: From Compact Packing to Functional Aggregates. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1706558. [PMID: 29740924 DOI: 10.1002/adma.201706558] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/07/2017] [Indexed: 06/08/2023]
Abstract
Quantum strongly correlated systems that exhibit interesting features in condensed matter physics often need an unachievable temperature or pressure range in classical materials. One solution is to introduce a scaling factor, namely, the lattice parameter. Synthetic heterostructures named superlattices or supracrystals are synthesized by the assembling of colloidal atoms. These include semiconductors, metals, and insulators for the exploitation of their unique properties. Most of them are currently limited to dense packing. However, some of desired properties need to adjust the colloidal atoms neighboring number. Here, the current state of research in nondense packing is summarized, discussing the benefits, outlining possible scenarios and methodologies, describing examples reported in the literature, briefly discussing the challenges, and offering preliminary conclusions. Penetrating such new and intriguing research fields demands a multidisciplinary approach accounting for the coupling of statistic physics, solid state and quantum physics, chemistry, computational science, and mathematics. Standard interactions between colloidal atoms and emerging fields, such as the use of Casimir forces, are reported. In particular, the focus is on the novelty of patchy colloidal atoms to meet this challenge.
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Affiliation(s)
- Xavier Bouju
- Centre d'élaboration de matériaux et d'études structurales (CEMES), CNRS, Université de Toulouse, UPR CNRS 8011, 29 Rue J. Marvig, F-31055, Toulouse, France
- Observatoire des micro et nanotechnologies (OMNT), Minatec, 17 rue des Martyrs, F-38000, Grenoble, France
| | - Étienne Duguet
- Observatoire des micro et nanotechnologies (OMNT), Minatec, 17 rue des Martyrs, F-38000, Grenoble, France
- CNRS, Univ. Bordeaux, ICMCB, UMR 5026, F-33600, Pessac, France
| | - Fabienne Gauffre
- Observatoire des micro et nanotechnologies (OMNT), Minatec, 17 rue des Martyrs, F-38000, Grenoble, France
- Institut des sciences chimiques de Rennes (ISCR), CNRS, Université de Rennes, UMR CNRS 6226, 263 avenue du Général Leclerc, F-35000, Rennes, France
| | - Claude R Henry
- Observatoire des micro et nanotechnologies (OMNT), Minatec, 17 rue des Martyrs, F-38000, Grenoble, France
- Centre interdisciplinaire de nanoscience de Marseille (CINAM), CNRS, Aix-Marseille Université, UMR CNRS 7325, Campus de Luminy, F-13288, Marseille, France
| | - Myrtil L Kahn
- Observatoire des micro et nanotechnologies (OMNT), Minatec, 17 rue des Martyrs, F-38000, Grenoble, France
- Laboratoire de chimie de coordination (LCC), CNRS, Université de Toulouse, UPR CNRS 8241, F-31000, Toulouse, France
| | - Patrice Mélinon
- Observatoire des micro et nanotechnologies (OMNT), Minatec, 17 rue des Martyrs, F-38000, Grenoble, France
- Institut Lumière Matière (ILM), CNRS, Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5306, F-69622, Villeurbanne, France
| | - Serge Ravaine
- CNRS, Univ. Bordeaux, CRPP, UMR 5031, F-33600, Pessac, France
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29
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Kister T, Monego D, Mulvaney P, Widmer-Cooper A, Kraus T. Colloidal Stability of Apolar Nanoparticles: The Role of Particle Size and Ligand Shell Structure. ACS NANO 2018; 12:5969-5977. [PMID: 29842786 DOI: 10.1021/acsnano.8b02202] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Being able to predict and tune the colloidal stability of nanoparticles is essential for a wide range of applications, yet our ability to do so is currently poor due to a lack of understanding of how they interact with one another. Here, we show that the agglomeration of apolar particles is dominated by either the core or the ligand shell depending on the particle size and materials. We do this by using small-angle X-ray scattering and molecular dynamics simulations to characterize the interaction between hexadecanethiol passivated gold nanoparticles in decane solvent. For smaller particles, the agglomeration temperature and interparticle spacing are determined by ordering of the ligand shell into bundles of aligned ligands that attract one another and interlock. In contrast, the agglomeration of larger particles is driven by van der Waals attraction between the gold cores, which eventually becomes strong enough to compress the ligand shell. Our results provide a microscopic description of the forces that determine the colloidal stability of apolar nanoparticles and explain why classical colloid theory fails.
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Affiliation(s)
- Thomas Kister
- INM-Leibniz Institute for New Materials , Campus D2 2 , 66123 Saarbrücken , Germany
| | - Debora Monego
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Paul Mulvaney
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Asaph Widmer-Cooper
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Tobias Kraus
- INM-Leibniz Institute for New Materials , Campus D2 2 , 66123 Saarbrücken , Germany
- Colloid and Interface Chemistry , Saarland University , Campus D2 2 , 66123 Saarbrücken , Germany
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30
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Shen Y, Gee MY, Greytak AB. Purification technologies for colloidal nanocrystals. Chem Commun (Camb) 2018; 53:827-841. [PMID: 27942615 DOI: 10.1039/c6cc07998a] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Almost all applications of colloidal nanocrystals require some type of purification or surface modification process following nanocrystal growth. Nanocrystal purification - the separation of nanocrystals from undesired solution components - can perturb the surface chemistry and thereby the physical properties of colloidal nanocrystals due to changes in solvent, solute concentrations, and exposure of the nanocrystal surface to oxidation or hydrolysis. For example, nanocrystal quantum dots frequently exhibit decreased photoluminescence brightness after precipitation from the growth solvent and subsequent redissolution. Consequently, purification is an integral part of the synthetic chemistry of colloidal nanocrystals, and the effect of purification methods must be considered in order to accurately compare and predict the behavior of otherwise similar nanocrystal samples. In this Feature Article we examine established and emerging approaches to the purification of colloidal nanoparticles from a nanocrystal surface chemistry viewpoint. Purification is generally achieved by exploiting differences in properties between the impurities and the nanoparticles. Three distinct properties are typically manipulated: polarity (relative solubility), electrophoretic mobility, and size. We discuss precipitation, extraction, electrophoretic methods, and size-based methods including ultracentrifugation, ultrafiltration, diafiltration, and size-exclusion chromatography. The susceptibility of quantum dots to changes in surface chemistry, with changes in photoluminescence decay associated with surface chemical changes, extends even into the case of core/shell structures. Accordingly, the goal of a more complete description of quantum dot surface chemistry has been a driver of innovation in colloidal nanocrystal purification methods. We specifically examine the effect of purification on surface chemistry and photoluminescence in quantum dots as an example of the challenges associated with nanocrystal purification and how improved understanding can result from increasingly precise techniques, and associated surface-sensitive analytical methods.
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Affiliation(s)
- Yi Shen
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA.
| | - Megan Y Gee
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA.
| | - A B Greytak
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA. and USC Nanocenter, University of South Carolina, Columbia, SC 29208, USA
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31
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Jana S, de Frutos M, Davidson P, Abécassis B. Ligand-induced twisting of nanoplatelets and their self-assembly into chiral ribbons. SCIENCE ADVANCES 2017; 3:e1701483. [PMID: 28924613 PMCID: PMC5597308 DOI: 10.1126/sciadv.1701483] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/26/2017] [Indexed: 05/20/2023]
Abstract
The emergence of chirality is a central issue in chemistry, materials science, and biology. In nanoparticle assemblies, chirality has been shown to arise through a few different processes, but chiral organizations composed of plate-like nanoparticles, a class of material under scrutiny due to their wide applicative potential, have not yet been reported. We show that ribbons of stacked board-shaped cadmium selenide (CdSe) nanoplatelets (NPLs) twist upon the addition of oleic acid ligand, leading to chiral ribbons that reach several micrometers in length and display a well-defined pitch of ~400 nm. We demonstrate that the chirality originates from surface strain caused by the ligand because isolated NPLs in dilute solution undergo a transition from a flat to a twisted shape as the ligand coverage increases. When the platelets are closely stacked within ribbons, the individual twist propagates over the whole ribbon length. These results show that a ligand-induced mechanical stress can strongly distort thin NPLs and that this stress can be expressed at a larger scale, paving the way to stress engineering in assemblies of nanocrystals. Such a structural change resulting from a simple external stimulus could have broad implications for the design of sensors and other responsive materials.
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Affiliation(s)
- Santanu Jana
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Université Paris-Sud, UMR 8502, 91405 Orsay, France
- Laboratoire de Chimie, ENS de Lyon, CNRS, UMR 5182, Université Claude Bernard, Université de Lyon, 69007 Lyon, France
| | - Marta de Frutos
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Université Paris-Sud, UMR 8502, 91405 Orsay, France
| | - Patrick Davidson
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Université Paris-Sud, UMR 8502, 91405 Orsay, France
| | - Benjamin Abécassis
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Université Paris-Sud, UMR 8502, 91405 Orsay, France
- Laboratoire de Chimie, ENS de Lyon, CNRS, UMR 5182, Université Claude Bernard, Université de Lyon, 69007 Lyon, France
- Corresponding author.
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32
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Coughlan C, Ibáñez M, Dobrozhan O, Singh A, Cabot A, Ryan KM. Compound Copper Chalcogenide Nanocrystals. Chem Rev 2017; 117:5865-6109. [PMID: 28394585 DOI: 10.1021/acs.chemrev.6b00376] [Citation(s) in RCA: 301] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review captures the synthesis, assembly, properties, and applications of copper chalcogenide NCs, which have achieved significant research interest in the last decade due to their compositional and structural versatility. The outstanding functional properties of these materials stems from the relationship between their band structure and defect concentration, including charge carrier concentration and electronic conductivity character, which consequently affects their optoelectronic, optical, and plasmonic properties. This, combined with several metastable crystal phases and stoichiometries and the low energy of formation of defects, makes the reproducible synthesis of these materials, with tunable parameters, remarkable. Further to this, the review captures the progress of the hierarchical assembly of these NCs, which bridges the link between their discrete and collective properties. Their ubiquitous application set has cross-cut energy conversion (photovoltaics, photocatalysis, thermoelectrics), energy storage (lithium-ion batteries, hydrogen generation), emissive materials (plasmonics, LEDs, biolabelling), sensors (electrochemical, biochemical), biomedical devices (magnetic resonance imaging, X-ray computer tomography), and medical therapies (photochemothermal therapies, immunotherapy, radiotherapy, and drug delivery). The confluence of advances in the synthesis, assembly, and application of these NCs in the past decade has the potential to significantly impact society, both economically and environmentally.
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Affiliation(s)
- Claudia Coughlan
- Department of Chemical Sciences and Bernal Institute, University of Limerick , Limerick, Ireland
| | - Maria Ibáñez
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain
| | - Oleksandr Dobrozhan
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain.,Department of Electronics and Computing, Sumy State University , 2 Rymskogo-Korsakova st., 40007 Sumy, Ukraine
| | - Ajay Singh
- Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Andreu Cabot
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Kevin M Ryan
- Department of Chemical Sciences and Bernal Institute, University of Limerick , Limerick, Ireland
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33
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Boles MA, Engel M, Talapin DV. Self-Assembly of Colloidal Nanocrystals: From Intricate Structures to Functional Materials. Chem Rev 2016; 116:11220-89. [PMID: 27552640 DOI: 10.1021/acs.chemrev.6b00196] [Citation(s) in RCA: 1014] [Impact Index Per Article: 126.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Chemical methods developed over the past two decades enable preparation of colloidal nanocrystals with uniform size and shape. These Brownian objects readily order into superlattices. Recently, the range of accessible inorganic cores and tunable surface chemistries dramatically increased, expanding the set of nanocrystal arrangements experimentally attainable. In this review, we discuss efforts to create next-generation materials via bottom-up organization of nanocrystals with preprogrammed functionality and self-assembly instructions. This process is often driven by both interparticle interactions and the influence of the assembly environment. The introduction provides the reader with a practical overview of nanocrystal synthesis, self-assembly, and superlattice characterization. We then summarize the theory of nanocrystal interactions and examine fundamental principles governing nanocrystal self-assembly from hard and soft particle perspectives borrowed from the comparatively established fields of micrometer colloids and block copolymer assembly. We outline the extensive catalog of superlattices prepared to date using hydrocarbon-capped nanocrystals with spherical, polyhedral, rod, plate, and branched inorganic core shapes, as well as those obtained by mixing combinations thereof. We also provide an overview of structural defects in nanocrystal superlattices. We then explore the unique possibilities offered by leveraging nontraditional surface chemistries and assembly environments to control superlattice structure and produce nonbulk assemblies. We end with a discussion of the unique optical, magnetic, electronic, and catalytic properties of ordered nanocrystal superlattices, and the coming advances required to make use of this new class of solids.
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Affiliation(s)
- Michael A Boles
- Department of Chemistry and James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States
| | - Michael Engel
- Institute for Multiscale Simulation, Friedrich-Alexander University Erlangen-Nürnberg , 91052 Erlangen, Germany.,Department of Chemical Engineering, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Dmitri V Talapin
- Department of Chemistry and James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.,Center for Nanoscale Materials, Argonne National Lab , Argonne, Illinois 60439, United States
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