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Antonsson J, Hamngren Blomqvist C, Olsson E, Gebäck T, Särkkä A. Modeling Colloidal Particle Aggregation Using Cluster Aggregation with Multiple Particle Interactions. J Phys Chem B 2024; 128:4513-4524. [PMID: 38686494 PMCID: PMC11089502 DOI: 10.1021/acs.jpcb.3c07992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/18/2024] [Accepted: 04/09/2024] [Indexed: 05/02/2024]
Abstract
In this study, we investigate the aggregation dynamics of colloidal silica by generating simulated structures and comparing them to experimental data gathered through scanning transmission electron microscopy (STEM). More specifically, diffusion-limited cluster aggregation and reaction-limited cluster aggregation models with different functions for the probability of particles sticking upon contact were used. Aside from using a constant sticking probability, the sticking probability was allowed to depend on the masses of the colliding clusters and on the number of particles close to the collision between clusters. The different models of the sticking probability were evaluated based on the goodness-of-fit of spatial summary statistics. Furthermore, the models were compared to the experimental data by calculating the structures' fractal dimension and mass transport properties from simulations of flow and diffusion. The sticking probability, depending on the interaction with multiple particles close to the collision site, led to structures most similar to the STEM data.
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Affiliation(s)
- Jakob Antonsson
- Department
of Mathematical Sciences, Chalmers University
of Technology and University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | | | - Eva Olsson
- Department
of Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Tobias Gebäck
- Department
of Mathematical Sciences, Chalmers University
of Technology and University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Aila Särkkä
- Department
of Mathematical Sciences, Chalmers University
of Technology and University of Gothenburg, SE-412 96 Gothenburg, Sweden
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2
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Jiang J, Sun W, Luo N. Shock-Induced Microstructural Evolution, Phase Transformation, Sintering of Al-Ni Dissimilar Nanoparticles: A Molecular Dynamics Study. Chemphyschem 2023:e202300419. [PMID: 37794826 DOI: 10.1002/cphc.202300419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 10/04/2023] [Accepted: 10/04/2023] [Indexed: 10/06/2023]
Abstract
Molecular dynamic simulations have been performed to explore contact behavior, microstructure evolution and sintering mechanism of Al-Ni dissimilar nanoparticles under high-velocity impact. We confirmed that the simulated contact stress, contact radius, and contact force under low-velocity impact are in good agreement with the predicted results of the Hertz model. However, with increasing the impact velocity, the simulated results gradually deviate from the predicted results of the Hertz model due to the elastic-plastic transition and atomic discrete structure. The normalized contact radius versus strain exhibits a weak dependence on nanosphere diameter. Below a critical velocity, there are very few HCP atoms in the nanospheres after thermal equilibrium. There are two different sintering mechanisms: under low-velocity impact, the sintering process relies mainly on the dislocation slip of Al nanospheres, while the dislocation slip of Ni nanospheres and the atomic diffusion of Al nanospheres predominate under high-velocity impact.
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Affiliation(s)
- Jun Jiang
- State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, 100081, China
- Beijing Institute of Technology Chongqing Innovation Center, Chongqing, 401120, China
- Explosion Protection and Emergency Disposal Technology Engineering Research Center of the Ministry of Education, Beijing, 10081, China
| | - Weifu Sun
- State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, 100081, China
- Beijing Institute of Technology Chongqing Innovation Center, Chongqing, 401120, China
- Explosion Protection and Emergency Disposal Technology Engineering Research Center of the Ministry of Education, Beijing, 10081, China
| | - Ning Luo
- School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou, 221116, China
- State Key Laboratory for Geomechanics & Deep Underground Engineering, Xuzhou, 221116, China
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3
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Contact force models for non-spherical particles with different surface properties: A review. POWDER TECHNOL 2023. [DOI: 10.1016/j.powtec.2023.118323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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4
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Line Patterns and Fractured Coatings in Deposited Colloidal Hydrochar on Glass Substrates after Evaporation of Water. COLLOIDS AND INTERFACES 2022. [DOI: 10.3390/colloids6020036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Patterns of assembled colloidal particles can form on substrates due to solvent evaporation, and here we studied such phenomena in the drying of monodispersed colloidal hydrochar dispersions prepared by the hydrothermal carbonization of glucose and purified by dialysis. During the evaporation of water, line patterns or, in some cases, mud-like patterns formed. The line formation was investigated as a function of the pH of the dispersion, substrate shape, particle concentration, and concentration of sodium dodecylsulfate (SDS). The lines comprised dense assemblies of hydrochar particles. The line width increased with the successive evaporation of water. Sharper lines formed with the addition of SDS, which was ascribed to the effects of solubilization or moderated interactions. At greater particle concentrations, we also observed a continuous layer of colloidal particles between the lines. A mechanism for the line pattern formation derived from the literature on other colloids was proposed. Mud-like patterns formed on the substrate in concentrated samples without SDS addition and were put in the context of the formation of cracks in the drying of colloidal coatings. Hydrochars belong to carbon-rich colloids, which are of fundamental and technological importance. This research could be useful for in situ line printing within microfluidic devices, for example.
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Elucidating the Aromatic Properties of Covalent Organic Frameworks Surface for Enhanced Polar Solvent Adsorption. Polymers (Basel) 2021; 13:polym13111861. [PMID: 34205141 PMCID: PMC8199954 DOI: 10.3390/polym13111861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/08/2021] [Accepted: 05/09/2021] [Indexed: 11/17/2022] Open
Abstract
Covalent organic frameworks (COFs) have a distinguished surface as they are mostly made by boron, carbon, nitrogen and oxygen. Many applications of COFs rely on polarity, size, charge, stability and hydrophobicity/hydrophilicity of their surface. In this study, two frequently used COFs sheets, COF-1 and covalent triazine-based frameworks (CTF-1), are studied. In addition, a theoretical porous graphene (TPG) was included for comparison purposes. The three solid sheets were investigated for aromaticity and stability using quantum mechanics calculations and their ability for water and ethanol adsorption using molecular dynamics simulations. COF-1 demonstrated the poorest aromatic character due to the highest energy delocalization interaction between B–O bonding orbital of sigma type and unfilled valence-shell nonbonding of boron. CTF-1 was identified as the least kinetically stable and the most chemically reactive. Both COF-1 and CTF-1 showed good surface properties for selective adsorption of water via hydrogen bonding and electrostatic interactions. Among the three sheets, TPG’s surface was mostly affected by aromatic currents and localized π electrons on the phenyl rings which in turn made it the best platform for selective adsorption of ethanol via van der Waals interactions. These results can serve as guidelines for future studies on solvent adsorption for COFs materials.
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Mei J, Geng H, Yu H, Shi J, Zhao Y, Yu R, Liao J, Chen Y. Preparation and performance of oleylamine modified silica‐reinforced natural rubber composites. J Appl Polym Sci 2021. [DOI: 10.1002/app.49907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Junfei Mei
- School of Materials Science and Engineering Hainan University Haikou China
| | - Haoran Geng
- School of Materials Science and Engineering Hainan University Haikou China
| | - Han Yu
- School of Materials Science and Engineering Hainan University Haikou China
| | - Jia Shi
- School of Materials Science and Engineering Hainan University Haikou China
| | - Yanfang Zhao
- School of Materials Science and Engineering Hainan University Haikou China
| | - Rentong Yu
- School of Materials Science and Engineering Hainan University Haikou China
| | - Jianhe Liao
- School of Materials Science and Engineering Hainan University Haikou China
| | - Yongping Chen
- School of Materials Science and Engineering Hainan University Haikou China
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Numerical Simulation of the Rheological Behavior of Nanoparticulate Suspensions. MATERIALS 2020; 13:ma13194288. [PMID: 32992894 PMCID: PMC7579068 DOI: 10.3390/ma13194288] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 11/18/2022]
Abstract
Nanoparticles significantly alter the rheological properties of a polymer or monomeric resin with major effect on the further processing of the materials. In this matter, especially the influence of particle material and disperse properties on the viscosity is not yet understood fully, but can only be modelled to some extent empirically after extensive experimental effort. In this paper, a numerical study on an uncured monomeric epoxy resin, which is filled with boehmite nanoparticles, is presented to elucidate the working principles, which govern the rheological behavior of nanoparticulate suspensions and to simulate the suspension viscosity based on assessable material and system properties. To account for the effect of particle surface forces and hydrodynamic interactions on the rheological behavior, a resolved CFD is coupled with DEM. It can be shown that the particle interactions caused by surface forces induce velocity differences between the particles and their surrounding fluid, which result in increased drag forces and cause the additional energy dissipation during shearing. The paper points out the limits of the used simulation method and presents a correction technique with respect to the Péclet number, which broadens the range of applicability. Valuable information is gained for a future mechanistic modelling of nanoparticulate suspension viscosity by elucidating the interdependency between surface forces, shear rate and resulting drag forces on the particles.
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Yang P, Zeng Q, Dong K, Zhu H, Yu A. A New Interaction Force Model of Gold Nanorods Derived by Molecular Dynamics Simulation. NANOMATERIALS 2020; 10:nano10071293. [PMID: 32630171 PMCID: PMC7408490 DOI: 10.3390/nano10071293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 11/18/2022]
Abstract
Interactions between nanoparticles is one of the key factors governing their assembly for ordered structures. Understanding such interactions between non-spherical nanoparticles and developing a quantitative force model are critical to achieving the ordered structures for various applications. In the present study, the non-contact interactions of two identical gold nanorods (AuNRs) with different aspect ratios have been studied by molecular dynamics simulation. A new interaction potential and force model for two nanorods approaching side-by-side has been proposed as a function of particle surface separation and their relative orientation. In addition, the interaction potentials of two nanorods approaching in other typical orientation configurations (i.e., crossed, head-to-head and head-to-side) have also been investigated.
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Affiliation(s)
- Pan Yang
- School of Engineering, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; (P.Y.); (K.D.); (H.Z)
| | - Qinghua Zeng
- School of Engineering, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; (P.Y.); (K.D.); (H.Z)
- Centre for Infrastructure Engineering, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
- Correspondence:
| | - Kejun Dong
- School of Engineering, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; (P.Y.); (K.D.); (H.Z)
- Centre for Infrastructure Engineering, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Haiping Zhu
- School of Engineering, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; (P.Y.); (K.D.); (H.Z)
| | - Aibing Yu
- Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia;
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9
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Sun W, Jiang J, Chen P. Dynamic mechanical contact behaviours of amorphous nanoparticles subjected to high-speed impact. POWDER TECHNOL 2020. [DOI: 10.1016/j.powtec.2020.02.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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10
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Yang P, Zeng Q, Dong K, Zhu H. A quick method for developing interparticle force models of spherical gold nanoparticles from molecular dynamics simulation. POWDER TECHNOL 2020. [DOI: 10.1016/j.powtec.2019.10.105] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Zheng J, Han D, Zhao S, Ye X, Wang Y, Wu Y, Dong D, Liu J, Wu X, Zhang L. Constructing a Multiple Covalent Interface and Isolating a Dispersed Structure in Silica/Rubber Nanocomposites with Excellent Dynamic Performance. ACS APPLIED MATERIALS & INTERFACES 2018; 10:19922-19931. [PMID: 29745652 DOI: 10.1021/acsami.8b02358] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Realizing and manipulating a fine dispersion of silica nanoparticles (NPs) in the polymer matrix is always a great challenge. In this work, we first successfully synthesized N, N'-bis[3-(triethoxysilyl)propyl-isopropanol]-propane-1,3-diamine (TSPD), which was a new interface modifier, aiming to promote the dispersion of silica NPs. Through Fourier transform infrared spectroscopy, nuclear magnetic resonance analysis, and mass spectroscopy, we verified that TSPD contains together six ethoxy groups at its two ends. Then, we used this TSPD to modify the pure silica NPs, and this modified silica was abbreviated as D-MS, which is realized by the thermal gravimetric analysis examination, scanning electron microscopy analysis, and dynamic light scattering results. It was clearly observed that D-MS NPs are connected to one another but are not conglutinated tightly, exhibiting a novel predispersed structure with around 1-2 nm certain extent of interparticle distance. Next, we fabricated the following four elastomer nanocomposites such as pure silica/natural rubber (NR) composite (PS-NR), D-MS/NR composite (DMS-NR), bis-(γ-triethoxysilylpropyl)-tetrasulfide (TESPT)-modified silica/NR composite (TS-NR), and TESPT-modified D-MS/NR composite (T&DMS-NR) and found that the Payne effect is the smallest for T&DMS-NR via the combination use of the D-MS and the traditional coupling agent TESPT, which is attributed to its best dispersion state evidenced by the transmission electron microscopy results. Moreover, by measuring a series of other important mechanical performances such as the stress-strain curve, the dynamic strain dependence of the loss factor, and the heat build-up, we concluded that the T&DMS-NR system greatly exceeds those of the three other rubber composites. In general, this new approach provides a good opportunity to prepare a silica/rubber composite with excellent properties in mechanical strength and dynamic behavior by tailoring the fine dispersion of NPs.
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Affiliation(s)
| | | | | | | | | | | | - Dong Dong
- Beijing Red Avenue Innova Co., Ltd. , Unit 1, 2, 3, Building 10, No. 20 Kechuang Fourteenth Street, Beijing Economic-Technological Development Area (BDA) , Beijing 100176 , PR China
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12
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Interaction between water and acetic acid-sodium halide aerosol: A molecular dynamics study. POWDER TECHNOL 2017. [DOI: 10.1016/j.powtec.2016.12.082] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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13
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14
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Skeete Z, Cheng HW, Ngo QM, Salazar C, Sun W, Luo J, Zhong CJ. 'Squeezed' interparticle properties for plasmonic coupling and SERS characteristics of duplex DNA conjugated/linked gold nanoparticles of homo/hetero-sizes. NANOTECHNOLOGY 2016; 27:325706. [PMID: 27352636 DOI: 10.1088/0957-4484/27/32/325706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The formation of interparticle duplex DNA conjugates with gold nanoparticles constitutes the basis for interparticle plasmonic coupling responsible for surface-enhanced Raman scattering signal amplification, but understanding of its correlation with interparticle spatial properties and particle sizes, especially in aqueous solutions, remains elusive. This report describes findings of an investigation of interparticle plasmonic coupling based on experimental measurements of localized surface plasmon resonance and surface enhanced Raman scattering characteristics for gold nanoparticles in aqueous solutions upon introduction of interparticle duplex DNA conjugates to define the interparticle spatial properties. Theoretical simulations of the interparticle optical properties and electric field enhancement based on a dimer model have also been performed to aid the understanding of the experimental results. The results have revealed a 'squeezed' interparticle spatial characteristic in which the duplex DNA-defined distance is close or shorter than A-form DNA conformation, which are discussed in terms of the interparticle interactions, providing fresh insight into the interparticle double-stranded DNA-defined interparticle spatial properties for the design of highly-sensitive nanoprobes in solutions for biomolecular detection.
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Affiliation(s)
- Zakiya Skeete
- Department of Chemistry, State University of New York at Binghamton, Binghamton, NY 13902, USA
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15
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Abstract
Understanding interactions between inorganic nanoparticles (NPs) is central to comprehension of self-organization processes and a wide spectrum of physical, chemical, and biological phenomena. However, quantitative description of the interparticle forces is complicated by many obstacles that are not present, or not as severe, for microsize particles (μPs). Here we analyze the sources of these difficulties and chart a course for future research. Such difficulties can be traced to the increased importance of discreteness and fluctuations around NPs (relative to μPs) and to multiscale collective effects. Although these problems can be partially overcome by modifying classical theories for colloidal interactions, such an approach fails to manage the nonadditivity of electrostatic, van der Waals, hydrophobic, and other interactions at the nanoscale. Several heuristic rules identified here can be helpful for discriminating between additive and nonadditive nanoscale systems. Further work on NP interactions would benefit from embracing NPs as strongly correlated reconfigurable systems with diverse physical elements and multiscale coupling processes, which will require new experimental and theoretical tools. Meanwhile, the similarity between the size of medium constituents and NPs makes atomic simulations of their interactions increasingly practical. Evolving experimental tools can stimulate improvement of existing force fields. New scientific opportunities for a better understanding of the electronic origin of classical interactions are converging at the scale of NPs.
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Affiliation(s)
- Carlos A Silvera Batista
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ronald G Larson
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA. Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Nicholas A Kotov
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA. Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
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16
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Chen Z, Li Q, Chen C, Du J, Tong J, Jin X, Li Y, Yuan Y, Qin Y, Wei T, Sun W. Enhanced charge transport and photovoltaic performance induced by incorporating rare-earth phosphor into organic-inorganic hybrid solar cells. Phys Chem Chem Phys 2015; 16:24499-508. [PMID: 25307965 DOI: 10.1039/c4cp03232b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In this work, dysprosium ion decorated yttrium oxide (Dy(3+):Y2O3) nanocrystal phosphors were incorporated into TiO2 acceptor thin film in a bid to enhance the light harvest, charge separation and transfer in the hybrid solar cells. The results show that the energy level offset between the donor (P3HT) and the acceptor (Dy(3+):Y2O3-TiO2) has been narrowed down, thus leading to the enhanced electron and hole transports, and also photovoltaic performances as compared to pure TiO2 without incorporating Dy(3+):Y2O3. By applying femtosecond transient optical spectroscopy, after the incorporation of dopant Dy(3+):Y2O3 into TiO2 at 6 wt%, both the hot electron and hole transfer lifetimes have been shortened, that is, from 30.2 ps and 6.94 ns to 25.1 ps and 1.26 ns, respectively, and an enhanced efficiency approaching 3% was achieved as compared to 2.0% without doping, indicating that the energetic charges are captured more efficiently benefitting a higher power conversion efficiency. Moreover, these results reveal that both the conduction band (CB) and valence band (VB) edges of the acceptor were elevated by 0.57 and 0.32 eV, respectively, after incorporating 6 wt% Dy(3+):Y2O3. This work demonstrates that distinct energy level alignment engineered by Dy(3+):Y2O3 phosphor has an important role in pursuing efficient future solar cells and underscores the promising potential of rare-earth phosphor in solar applications.
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Affiliation(s)
- Zihan Chen
- Key Laboratory of Nondestructive Testing, Ministry of Education, Nanchang Hangkong University, Nanchang, 330063, P. R. China.
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18
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Lanzalaco S, Scialdone O, Galia A. Effect of interfacial area on heterogeneous free radical grafting of vinyl monomers in supercritical carbon dioxide: Grafting of acrylic acid on poly(vinylidenefluoride) nanoparticles. J Appl Polym Sci 2014. [DOI: 10.1002/app.41541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Sonia Lanzalaco
- Dipartimento Ingegneria Chimica Gestionale Informatica Meccanica; Università di Palermo; Viale delle Scienze Ed.6 90128 Palermo Italy
| | - Onofrio Scialdone
- Dipartimento Ingegneria Chimica Gestionale Informatica Meccanica; Università di Palermo; Viale delle Scienze Ed.6 90128 Palermo Italy
| | - Alessandro Galia
- Dipartimento Ingegneria Chimica Gestionale Informatica Meccanica; Università di Palermo; Viale delle Scienze Ed.6 90128 Palermo Italy
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19
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Jin X, Sun W, Chen C, Wei T, Cheng Y, Li P, Li Q. Efficiency enhancement via tailoring energy level alignment induced by vanadium ion doping in organic/inorganic hybrid solar cells. RSC Adv 2014. [DOI: 10.1039/c4ra08671f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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20
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Sun W, Zeng Q, Yu A. Computational studies on interparticle forces between nanoellipsoids. RSC Adv 2014. [DOI: 10.1039/c4ra06809b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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21
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Energy level control: toward an efficient hot electron transport. Sci Rep 2014; 4:5983. [PMID: 25099864 PMCID: PMC4124467 DOI: 10.1038/srep05983] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/18/2014] [Indexed: 12/21/2022] Open
Abstract
Highly efficient hot electron transport represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot electron capture and lost-cost devices remains a technological challenge, regulating the energy level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the ‘excess' energy offset between the conduction band of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence band and highest occupied molecular orbital. Strikingly, the hot electron transfer time has been shortened. This work demonstrates that suitable energy level alignment can be tuned to gain the higher hot electron/hole transport efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells.
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22
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Sun W, Li Y, Xu W, Mai YW. Interactions between crystalline nanospheres: comparisons between molecular dynamics simulations and continuum models. RSC Adv 2014. [DOI: 10.1039/c4ra05480f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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23
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Xu W, Zhou L, Sun W, Zhang J, Tu W. Effect of difunctional acids on the physicochemical, thermal, and mechanical properties of polyester polyol-based polyurethane coatings. J Appl Polym Sci 2014. [DOI: 10.1002/app.41246] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Wen Xu
- College of Materials and Mineral Resources; Xi'an University of Architecture and Technology; Xi'an People's Republic of China 710055
| | - Lipan Zhou
- School of Chemistry and Chemical Engineering; South China University of Technology; Guangzhou People's Republic of China 510640
| | - Weifu Sun
- School of Materials Science and Engineering; The University of New South Wales; Sydney 2052 Australia
| | - Junrui Zhang
- School of Chemistry and Chemical Engineering; South China University of Technology; Guangzhou People's Republic of China 510640
| | - Weiping Tu
- School of Chemistry and Chemical Engineering; South China University of Technology; Guangzhou People's Republic of China 510640
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24
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Schilde C, Burmeister CF, Kwade A. Measurement and simulation of micromechanical properties of nanostructured aggregates via nanoindentation and DEM-simulation. POWDER TECHNOL 2014. [DOI: 10.1016/j.powtec.2014.03.042] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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25
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Chandratilleke R, Yu A, Bridgwater J, Shinohara K. Flow and Mixing of Cohesive Particles in a Vertical Bladed Mixer. Ind Eng Chem Res 2014. [DOI: 10.1021/ie403877v] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Rohana Chandratilleke
- Laboratory
for Simulation and Modeling of Particulate Systems School of Materials
Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Aibing Yu
- Laboratory
for Simulation and Modeling of Particulate Systems School of Materials
Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - John Bridgwater
- Department
of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, U.K
| | - Kunio Shinohara
- Particulate Chemical
Engineering Laboratory, Sapporo 060-0051, Japan
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26
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Sun W. Interaction forces between a spherical nanoparticle and a flat surface. Phys Chem Chem Phys 2014; 16:5846-54. [DOI: 10.1039/c3cp55082f] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Darkins R, Sushko ML, Liu J, Duffy DM. Stress in titania nanoparticles: an atomistic study. Phys Chem Chem Phys 2014; 16:9441-7. [DOI: 10.1039/c3cp54357a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The size-dependent surface and bulk stresses intrinsic to titania nanoparticles are investigated using atomistic simulation. Surface charge is also shown to induce a significant tensile stress.
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Affiliation(s)
- Robert Darkins
- UCL Physics & Astronomy
- University College London
- London, UK
| | | | - Jun Liu
- Pacific Northwest National Laboratory
- Richland, USA
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Sun W. The dynamic effect on mechanical contacts between nanoparticles. NANOSCALE 2013; 5:12658-12669. [PMID: 24186146 DOI: 10.1039/c3nr04354a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The rich behaviors of high-speed mechanical contacts at the nanoscale have been studied. The seldom observed elastic-plastic transition governed by Hertz and Thornton models has been clearly unveiled, the origins of the hardening effect and the deformation mechanism of nanoscale plasticity have been discussed in terms of structural changes after compression and a series of physical quantities are measured including contact forces, contact radius, contact stress, coefficient of restitution and total impact time. Our simulation results closely resemble experiments and/or theoretical predictions: (i) when impact speed v is higher than Y/ρc0, the elastic-plastic deformation transition occurs, (ii) the yielded apparent elastic modulus and hardness are larger than those of the bulk, (iii) the initiating yield stress Y and hardness P0 still satisfy P0 ≈ 1.6Y, (iv) particle's volume decreases during compression, (v) contact radius a follows a [proportionality] v(2/5), (vi) at v ≥ 2000 m s(-1), the coefficient of restitution follows e [proportionality] v(-1/4) and (vii) the total time of impact follows Tc [proportionality] v(-1/5). However, there also exist many quantitative differences. The contact radius and final contact radius are underestimated by the continuum predictions while the total impact time is overestimated, but all of them reasonably agree with theoretical predictions with an increase of contact area and impact speed. The theoretical equation is adapted to predict the final contact radius during normal impact, in which the contact radius at zero load is also formulated.
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Affiliation(s)
- Weifu Sun
- School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
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Sun W, Zeng Q, Yu A, Kendall K. Calculation of normal contact forces between silica nanospheres. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:7825-7837. [PMID: 23687956 DOI: 10.1021/la401087j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this work, interaction forces between two silica nanospheres after contact, including the van der Waals (vdW) attraction, Born repulsion, and mechanical contact forces are studied by molecular dynamics (MD) simulations. The effects of interaction path (approach or departure), initial relative velocity, and relative orientations of two nanospheres are first examined. The results show that the interparticle forces are, to a large degree, independent of these variables. Then, emphasis is given to other important variables. At a small contact deformation, the size dependence of the vdW attraction and Born repulsion qualitatively agrees with the prediction based on the conventional theories, but this becomes vague upon further deformation due to the gradually flattened shape of deformed particles. An alternative approach is provided to calculate the interparticle vdW attraction and Born repulsion forces. Moreover, the MD simulations show that the Hertz model still holds to describe the mechanical contact force at low compression, which is obtained by subtracting the vdW attraction and Born repulsion forces from the total normal force. Comparisons with the Johnson-Kendall-Roberts (JKR) and Derjaguin-Muller-Toporov (DMT) models, in terms of force-displacement relationships and contact radius, show that the two models can be used to provide the first approximation, but there is some deviation from the MD simulated results. The origins of the quantitative difference are analyzed. New equations are formulated to estimate the interaction forces between silica nanospheres, which should be useful in the dynamic simulation of silica nanoparticle systems.
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Affiliation(s)
- Weifu Sun
- Laboratory for Simulation and Modeling of Particulate Systems, School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
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