1
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Daub CD, Kurtén T. Effect of an Electric Field on the Structure and Stability of Atmospheric Clusters. J Phys Chem A 2024; 128:646-655. [PMID: 38217515 DOI: 10.1021/acs.jpca.3c07260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
We study the influence of an applied electric field on the structure and stability of some common bimolecular clusters that are found in the atmosphere. These clusters play an important role in new particle formation (NPF). For low values of the electric field (i.e., |E| ≤ 0.01 V Å-1), we demonstrate that the field response of the clusters can be predicted from simply calculating the dipole moment of the cluster and the dipole moments of the constituent molecules and that the influence on the association energy of the cluster is minimal (i.e., <0.5 kcal mol-1). For higher field strengths |E| > 0.2 V Å-1, there can be more dramatic effects on both structure and energetics, as the induced dipole, charge transfer, and geometric distortion play a larger role. Although such large fields are not very relevant in the atmosphere, they do exist in some situations of experimental interest, such as near interfaces and in intense laser fields.
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Affiliation(s)
| | - Theo Kurtén
- Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki 00014, Finland
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2
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Reuter C, Ecke G, Strehle S. Exploring the Surface Oxidation and Environmental Instability of 2H-/1T'-MoTe 2 Using Field Emission-Based Scanning Probe Lithography. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310887. [PMID: 37931614 DOI: 10.1002/adma.202310887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Indexed: 11/08/2023]
Abstract
An unconventional approach for the resistless nanopatterning 2H- and 1T'-MoTe2 by means of scanning probe lithography is presented. A Fowler-Nordheim tunneling current of low energetic electrons (E = 30-60 eV) emitted from the tip of an atomic force microscopy (AFM) cantilever is utilized to induce a nanoscale oxidation on a MoTe2 nanosheet surface under ambient conditions. Due to the water solubility of the generated oxide, a direct pattern transfer into the MoTe2 surface can be achieved by a simple immersion of the sample in deionized water. The tip-grown oxide is characterized using Auger electron and Raman spectroscopy, revealing it consists of amorphous MoO3 /MoOx as well as TeO2 /TeOx . With the presented technology in combination with subsequent AFM imaging it is possible to demonstrate a strong anisotropic sensitivity of 1T'-/(Td )-MoTe2 to aqueous environments. Finally the discussed approach is used to structure a nanoribbon field effect transistor out of a few-layer 2H-MoTe2 nanosheet.
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Affiliation(s)
- Christoph Reuter
- Institute of Micro- and Nanotechnologies, Microsystems Technology Group, Technische Universität Ilmenau, Max-Planck-Ring 12, 98693, Ilmenau, Germany
| | - Gernot Ecke
- Institute of Micro- and Nanotechnologies, Nanotechnology Group, Technische Universität Ilmenau, Gustav-Kirchhoff-Straße 1, 98693, Ilmenau, Germany
| | - Steffen Strehle
- Institute of Micro- and Nanotechnologies, Microsystems Technology Group, Technische Universität Ilmenau, Max-Planck-Ring 12, 98693, Ilmenau, Germany
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3
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Severi M, Zerbetto F. Polaritonic Chemistry: Hindering and Easing Ground State Polyenic Isomerization via Breakdown of σ-π Separation. J Phys Chem Lett 2023; 14:9145-9149. [PMID: 37796008 PMCID: PMC10577679 DOI: 10.1021/acs.jpclett.3c02081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/06/2023] [Indexed: 10/06/2023]
Abstract
The ground state conformational isomerization in polyenes is a symmetry allowed process. Its low energy barrier is governed by electron density transfer from the formal single bond that is rotated to the nearby formal double bonds. Along the reaction pathway, the transition state is therefore destabilized. The rules of polaritonic chemistry, i.e., chemistry in a nanocavity with reflecting windows, are barely beginning to be laid out. The standing electric field of the nanocavity couples strongly with the molecular wave function and modifies the potential energy curve in unexpected ways. A quantum electrodynamics approach, applied to the torsional degree of freedom of the central bond of butadiene, shows that formation of the polariton mixes the σ-π frameworks thereby stabilizing/destabilizing the planar, reactant-like conformations. The values of the fundamental mode of the cavity field used in the absence of the cavity do not trigger this mechanism.
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Affiliation(s)
- Marco Severi
- Department
of Chemistry G. Ciamician, University of
Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Francesco Zerbetto
- Department
of Chemistry G. Ciamician, University of
Bologna, Via F. Selmi 2, 40126 Bologna, Italy
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4
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Pan X, Cao Q, Liu D, Wu Z. Effects of Contact Behavior and Electric Field on Electrohydrodynamics of Nanodroplets. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024422130222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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5
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Electric field direction-induced gas/water selectively entering nanochannel. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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6
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Scanning Probe Lithography: State-of-the-Art and Future Perspectives. MICROMACHINES 2022; 13:mi13020228. [PMID: 35208352 PMCID: PMC8878409 DOI: 10.3390/mi13020228] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/24/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023]
Abstract
High-throughput and high-accuracy nanofabrication methods are required for the ever-increasing demand for nanoelectronics, high-density data storage devices, nanophotonics, quantum computing, molecular circuitry, and scaffolds in bioengineering used for cell proliferation applications. The scanning probe lithography (SPL) nanofabrication technique is a critical nanofabrication method with great potential to evolve into a disruptive atomic-scale fabrication technology to meet these demands. Through this timely review, we aspire to provide an overview of the SPL fabrication mechanism and the state-the-art research in this area, and detail the applications and characteristics of this technique, including the effects of thermal aspects and chemical aspects, and the influence of electric and magnetic fields in governing the mechanics of the functionalized tip interacting with the substrate during SPL. Alongside this, the review also sheds light on comparing various fabrication capabilities, throughput, and attainable resolution. Finally, the paper alludes to the fact that a majority of the reported literature suggests that SPL has yet to achieve its full commercial potential and is currently largely a laboratory-based nanofabrication technique used for prototyping of nanostructures and nanodevices.
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7
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8
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Molecular dynamics simulation study of the effect of a strong electric field on the structure of a poly(oxyethylene) chain in explicit solvents. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Uhlig M, Garcia R. In Situ Atomic-Scale Imaging of Interfacial Water under 3D Nanoscale Confinement. NANO LETTERS 2021; 21:5593-5598. [PMID: 33983752 PMCID: PMC9135320 DOI: 10.1021/acs.nanolett.1c01092] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Capillary condensation of water from vapor is an everyday phenomenon which has a wide range of scientific and technological implications. Many aspects of capillary condensation are not well understood such as the structure of interfacial water, the existence of distinct properties of confined water, or the validity of the Kelvin equation at nanoscale. We note the absence of high-spatial resolution images inside a meniscus. Here, we develop an AFM-based method to provide in situ atomic-scale resolution maps of the solid-water interface of a nanomeniscus (80-250 nm3). The separation between the first two hydration layers on graphite is 0.30 nm, while on mica it is 0.28 nm. Those values are very close to the ones expected for the same surfaces immersed in bulk water. Thus, the hydration layer structure on a crystalline surface is independent of the water volume.
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10
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Yuan C, Chen DJ, Ye QX, Xiao K, Hao LS, Nan YQ. CO2/N2-switchable sol–gel transition based on NaDC/NaCl solution: Experiments and molecular dynamics simulations. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115193] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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11
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Xie Z, Li Z, Li J, Kou J, Yao J, Fan J. Electric field-induced gas dissolving in aqueous solutions. J Chem Phys 2021; 154:024705. [PMID: 33445907 DOI: 10.1063/5.0037387] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Gas dissolution or accumulation regulating in an aqueous environment is important but difficult in various fields. Here, we performed all-atom molecular dynamics simulations to study the dissolution/accumulation of gas molecules in aqueous solutions. It was found that the distribution of gas molecules at the solid-water interface is regulated by the direction of the external electric field. Gas molecules attach and accumulate to the interface with an electric field parallel to the interface, while the gas molecules depart and dissolve into the aqueous solutions with a vertical electric field. The above phenomena can be attributed to the redistribution of water molecules as a result of the change of hydrogen bonds of water molecules at the interface as affected by the electric field. This finding reveals a new mechanism of regulating gas accumulation and dissolution in aqueous solutions and can have tremendous applications in the synthesis of drugs, the design of microfluidic device, and the extraction of natural gas.
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Affiliation(s)
- Zhang Xie
- Institute of Condensed Matter Physics, Zhejiang Normal University, Jinhua 321004, China
| | - Zheng Li
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Jingyuan Li
- Department of Physics, Zhejiang University, Hangzhou 310058, China
| | - Jianlong Kou
- Institute of Condensed Matter Physics, Zhejiang Normal University, Jinhua 321004, China
| | - Jun Yao
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Jintu Fan
- Department of Fiber Science and Apparel Design, Cornell University, Ithaca, New York 14853-4401, USA
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12
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13
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Ebrahimi F, Maktabdaran GR, Sahimi M. Formation of a Stable Bridge between Two Disjoint Nanotubes with Single-File Chains of Water. J Phys Chem B 2020; 124:8340-8346. [PMID: 32894671 DOI: 10.1021/acs.jpcb.0c05331] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It was recently demonstrated that stable water bridges can form between two relatively large disjoint nanochannels, such as carbon nanotubes (CNTs), under an applied pressure drop. Such bridges are relevant to fabrication of nanostructured materials, drug delivery, water desalination devices, hydrogen fuel cells, dip-pen nanolithography, and several other applications. If the nanotubes are small enough, however, then one has only single-file hydrogen-bonded chains of water molecules. The distribution of water in such nanotubes manifests unusual physical properties that are attributed to the low number of hydrogen bonds (HBs) formed in the channel since, on average, each water molecule in a single-file chain forms only 1.7 HBs, almost half of the value for bulk water. Using extensive molecular dynamics simulations, we demonstrate that stable bridges can form even between two small disjoint CNTs that contain single-file chains of water. The structure, stability, and properties of such bridges and their dependence on the applied pressure drop and the length of the gap between the two CNTs are studied in detail, as is the distribution of the HBs. We demonstrate, in particular, that the efficiency of flow through the bridge is at maximum at a specific pressure difference.
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Affiliation(s)
- Fatemeh Ebrahimi
- Department of Physics, University of Birjand, Birjand 97175-615, Iran
| | - G R Maktabdaran
- Department of Physics, University of Birjand, Birjand 97175-615, Iran
| | - Muhammad Sahimi
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-1211, United States
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14
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Sun CQ. Water electrification: Principles and applications. Adv Colloid Interface Sci 2020; 282:102188. [PMID: 32610204 DOI: 10.1016/j.cis.2020.102188] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/30/2020] [Accepted: 06/02/2020] [Indexed: 01/20/2023]
Abstract
Deep engineering of liquid water by charge and impurity injection, charged support, current flow, hydrophobic confinement, or applying a directional field has becoming increasingly important to the mankind toward overcoming energy and environment crisis. One can mediate the processes or temperatures of molecular evaporation for clean water harvesting, HO bond dissociation for H2 fuel generation, solidification for living-organism cryopreservation, structure stiffening for bioengineering, etc., with mechanisms being still puzzling. We show that the framework of "hydrogen bonding and electronic dynamics" has substantiated the progress in the fundamental issues and the aimed engineering. The segmental disparity of the coupled hydrogen bond (O:HO or HB with ":" being lone pair of oxygen) resolves their specific-heat curves and turns out a quasisolid phase (QS, bound at -15 and 4 °C). Electrification shows dual functionality that not only aligns, orders, polarizes water molecules but also stretches the O:HO bond. The O:HO segmental cooperative relaxation and polarization shift the QS boundary through Einstein's relation, ΔΘDx ∝ Δωx, resulting in a gel-like, viscoelastic, and stable supersolid phase with raised melting point Tm and lowered temperatures for vaporization TV and ice nucleation TN. The supersolidity and electro structure ordering provide additional forces to reinforce Armstrong's water bridge. QS dispersion and the secondary effect of electrification such as compression define the TN for Dufour's electro-freezing. The TV depression, surface stress disruption, and electrostatic attraction raise Asakawa's molecular evaporability. Composition of opposite, compatible fields eases the HO dissociation and soil wetting. Progress evidences not only the essentiality of the coupled O:HO bond theory but also the feasibility of engineering water and solutions by programmed electrification.
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Affiliation(s)
- Chang Q Sun
- School of EEE, Nanyang Technological University, 639798, Singapore; School of Material Science and Engineering, Jilin University, Changchun 130022, China.
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15
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Lang H, Peng Y, Cao X, Zou K. Atomic-Scale Friction Characteristics of Graphene under Conductive AFM with Applied Voltages. ACS APPLIED MATERIALS & INTERFACES 2020; 12:25503-25511. [PMID: 32394710 DOI: 10.1021/acsami.0c06868] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The current-carrying nanofriction characteristics play an important role in the performance, reliability, and lifetime of graphene-based micro/nanoelectromechanical systems and nanoelectronic devices. The atomic-scale friction characteristics of graphene were investigated using conductive atomic force microscopy by applying positive-bias and negative-bias voltages. The atomic-scale friction increased with applied voltages. Also, the friction under positive-bias voltages was lower than under negative-bias voltages, and the friction difference increased with the voltages. The different frictional behaviors resulted from the inherent work function difference and the water molecules between the tip and graphene. The applied voltages amplified the effect of the work function difference on the friction, and the water molecules played different roles under negative-bias and positive-bias voltages. The friction increased rapidly with the continuous increase of negative-bias voltages due to the electrochemical oxidation of graphene. Nevertheless, the friction under positive-bias voltages remained low and the structure of graphene was unchanged. These experimental observations were further explained by modeling the atomic-scale friction with a modified Prandtl-Tomlinson model. The model allowed the determination of the basic potential barrier and the voltage-induced potential barrier between the tip and graphene. The calculation based on the model indicated that the negative-bias voltages induced a larger potential barrier than the positive-bias voltages. The studies suggest that graphene can show a better lubricant performance by working as a lubricant coating for the cathodes of the sliding electrical contact interfaces.
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Affiliation(s)
- Haojie Lang
- College of Mechanical Engineering, Donghua University, Shanghai 201620, China
| | - Yitian Peng
- Shanghai Collaborative Innovation Center for High Performance Fiber Composites, Donghua University, Shanghai 201620, China
- College of Mechanical Engineering, Donghua University, Shanghai 201620, China
- Engineering Research Center of Advanced Textile Machinery, Donghua University, Shanghai 201620, China
| | - Xing'an Cao
- College of Mechanical Engineering, Donghua University, Shanghai 201620, China
| | - Kun Zou
- College of Mechanical Engineering, Donghua University, Shanghai 201620, China
- Engineering Research Center of Advanced Textile Machinery, Donghua University, Shanghai 201620, China
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16
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Xiong H, Devegowda D, Huang L. Oil–water
transport in
clay‐hosted
nanopores: Effects of
long‐range
electrostatic forces. AIChE J 2020. [DOI: 10.1002/aic.16276] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Hao Xiong
- Mewbourne School of Petroleum and Geological EngineeringThe University of Oklahoma Norman Oklahoma USA
| | - Deepak Devegowda
- Mewbourne School of Petroleum and Geological EngineeringThe University of Oklahoma Norman Oklahoma USA
| | - Liangliang Huang
- Chemical, Biological & Materials EngineeringThe University of Oklahoma Norman Oklahoma USA
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17
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Rai S, Sharma N, Rai D. Structured water chains in external electric fields. Mol Phys 2020. [DOI: 10.1080/00268976.2019.1662957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Smita Rai
- Department of Physics, Sikkim University, Samdur, India
| | - Nayan Sharma
- Department of Physics, Sikkim University, Samdur, India
| | - Dhurba Rai
- Department of Physics, Sikkim University, Samdur, India
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18
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Wan Y, Gao Y, Wang J, Yang Y, Xia Z. Rapid Water Harvesting and Nonthermal Drying in Humid Air by N-Doped Graphene Micropads. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:12389-12399. [PMID: 31474111 DOI: 10.1021/acs.langmuir.9b01852] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We demonstrate a novel nanotextured graphene micropad that can rapidly harvest water from air to generate microscale water droplets with the desired size in designated positions on demand by simply applying a negative electric bias of -1.5 to -15 V. More interestingly, the water droplets can be reversibly dried nonthermally with the pad at ambient temperature in humid air (∼85% RH) by applying a positive electric bias of +1.5 to +15 V. The harvesting and drying rates on the glass are 2.7 and 1.5 μm3/s under biases of -15 and +15 V, respectively, but no apparent harvesting or drying activities are observed without the bias. The energy consumption is minimal as there is no Joule current due to the insulative substrate. It is shown that substrate wettability and ions play an important role in enabling the fast water harvesting and nonthermal drying. Molecular modeling is developed to understand the harvesting and drying mechanisms at the atomic scale. The water harvesting/drying approach may be useful for many technological applications such as micro/nanolithography, 3D printing, MEMS, and biochemical and microfluid devices.
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Affiliation(s)
- Yiyang Wan
- Department of Materials Science and Engineering, and Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
| | - Yong Gao
- Department of Materials Science and Engineering, and Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
- School of Materials Science and Engineering , Northwestern Polytechnical University , Xi'an , Shaanxi 710072 , P. R. China
| | - Jie Wang
- Department of Materials Science and Engineering, and Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
- School of Materials Science and Engineering , Northwestern Polytechnical University , Xi'an , Shaanxi 710072 , P. R. China
| | - Yanqing Yang
- School of Materials Science and Engineering , Northwestern Polytechnical University , Xi'an , Shaanxi 710072 , P. R. China
| | - Zhenhai Xia
- Department of Materials Science and Engineering, and Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
- School of Materials Science and Engineering , Northwestern Polytechnical University , Xi'an , Shaanxi 710072 , P. R. China
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19
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Wan Y, Gao Y, Xia Z. Highly Switchable Adhesion of N-Doped Graphene Interfaces for Robust Micromanipulation. ACS APPLIED MATERIALS & INTERFACES 2019; 11:5544-5553. [PMID: 30648852 DOI: 10.1021/acsami.8b18793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We demonstrated an N-doped graphene interface with highly switchable adhesion and robust micromanipulation capability triggered by external electric signals. Upon applying a small dc or ac electrical bias, this nanotextured surface can collect environmental moisture to form a large number of water bridges between the graphene and target surface, which lead to a drastic change in adhesive force. Turning on and off the electrical bias can control this graphene interface as a robust micro/nanomanipulator to pick up and drop off various micro/nano-objects for precise assembling. Molecular dynamics simulation reveals that the electrically induced electric double layer and ordered icelike structures at the graphene-water interface strengthen the water bridges and consequently enhance force switchability. In addition to the micro-/nanomanipulation, this switchable adhesion may have many technical implications such as climbing robots, sensors, microfluidic devices, and advanced drug delivery.
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Affiliation(s)
- Yiyang Wan
- Department of Materials Science and Engineering, and Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
| | - Yong Gao
- Department of Materials Science and Engineering, and Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
- School of Materials Science and Engineering , Northwestern Polytechnical University , Xi'an , Shaanxi 710072 , P. R. China
| | - Zhenhai Xia
- Department of Materials Science and Engineering, and Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
- School of Materials Science and Engineering , Northwestern Polytechnical University , Xi'an , Shaanxi 710072 , P. R. China
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20
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The Impact of the Electric Field on Surface Condensation of Water Vapor: Insight from Molecular Dynamics Simulation. NANOMATERIALS 2019; 9:nano9010064. [PMID: 30621199 PMCID: PMC6359217 DOI: 10.3390/nano9010064] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/18/2018] [Accepted: 12/27/2018] [Indexed: 11/26/2022]
Abstract
In this study, molecular dynamics simulations were carried out to study the coupling effect of electric field strength and surface wettability on the condensation process of water vapor. Our results show that an electric field can rotate water molecules upward and restrict condensation. Formed clusters are stretched to become columns above the threshold strength of the field, causing the condensation rate to drop quickly. The enhancement of surface attraction force boosts the rearrangement of water molecules adjacent to the surface and exaggerates the threshold value for shape transformation. In addition, the contact area between clusters and the surface increases with increasing amounts of surface attraction force, which raises the condensation efficiency. Thus, the condensation rate of water vapor on a surface under an electric field is determined by competition between intermolecular forces from the electric field and the surface.
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21
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Fukuma T, Garcia R. Atomic- and Molecular-Resolution Mapping of Solid-Liquid Interfaces by 3D Atomic Force Microscopy. ACS NANO 2018; 12:11785-11797. [PMID: 30422619 DOI: 10.1021/acsnano.8b07216] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Hydration layers are ubiquitous in life and technology. Hence, interfacial aqueous layers have a central role in a wide range of phenomena from materials science to molecular and cell biology. A complete understanding of those processes requires, among other things, the development of very-sensitive and high-resolution instruments. Three-dimensional atomic force microscopy (3D-AFM) represents the latest and most successful attempt to generate atomically resolved three-dimensional images of solid-liquid interfaces. This review provides an overview of the 3D-AFM operating principles and its underlying physics. We illustrate and explain the capability of the instrument to resolve atomic defects on crystalline surfaces immersed in liquid. We also illustrate some of its applications to imaging the hydration structures on DNA or proteins. In the last section, we discuss some perspectives on emerging applications in materials science and molecular biology.
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Affiliation(s)
- Takeshi Fukuma
- Nano Life Science Institute (WPI-NanoLSI) , Kanazawa University , Kanazawa 920-1192 , Japan
| | - Ricardo Garcia
- Materials Science Factory , Instituto de Ciencia de Materiales de Madrid (ICMM) , 28049 Madrid , Spain
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22
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Li H, Ying Z, Lyu B, Deng A, Wang L, Taniguchi T, Watanabe K, Shi Z. Electrode-Free Anodic Oxidation Nanolithography of Low-Dimensional Materials. NANO LETTERS 2018; 18:8011-8015. [PMID: 30499679 DOI: 10.1021/acs.nanolett.8b04166] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Scanning probe lithography based on local anodic oxidation (LAO) provides a robust and general nanolithography tool for a wide range of applications. Its practical use, however, has been strongly hampered due to the requirement of a prefabricated microelectrode to conduct the driving electrical current. Here we report a novel electrode-free LAO technique, which enables in situ patterning of as-prepared low-dimensional materials and heterostructures with great flexibility and high precision. Unlike conventional LAO driven by a direct current, the electrode-free LAO is driven by a high-frequency (>10 kHz) alternating current applied through capacitive coupling, which eliminates the need of a contacting electrode and can be used even for tailoring insulating materials. Using this technique, we demonstrated flexible nanolithography of graphene, hexagonal boron nitride, and carbon nanotubes on insulating substrates with ∼10-nanometer precision. In addition, the electrode-free LAO exhibits high etching quality without oxide residues left. Such an in situ and electrode-free nanolithography with high etching quality opens up new opportunities for fabricating ultraclean nanoscale devices and heterostructures with great flexibility.
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Affiliation(s)
- Hongyuan Li
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Zhe Ying
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Bosai Lyu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Aolin Deng
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Lele Wang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Takashi Taniguchi
- National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Japan
| | - Kenji Watanabe
- National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Japan
| | - Zhiwen Shi
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
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Consta S, Oh MI, Sharawy M, Malevanets A. Macroion–Solvent Interactions in Charged Droplets. J Phys Chem A 2018; 122:5239-5250. [DOI: 10.1021/acs.jpca.8b01404] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Styliani Consta
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Myong In Oh
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Mahmoud Sharawy
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Anatoly Malevanets
- Department of Electrical and Computer Engineering, The University of University of Western Ontario, London, Ontario, Canada N6A 5B9
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Ye H, Zheng Y, Zhou L, Zhao J, Zhang H, Chen Z. Divergent effect of electric fields on the mechanical property of water-filled carbon nanotubes with an application as a nanoscale trigger. NANOTECHNOLOGY 2018; 29:025707. [PMID: 29226852 DOI: 10.1088/1361-6528/aa98ee] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Polar water molecules exhibit extraordinary phenomena under nanoscale confinement. Through the application of an electric field, a water-filled carbon nanotube (CNT) that has been successfully fabricated in the laboratory is expected to have distinct responses to the external electricity. Here, we examine the effect of electric field direction on the mechanical property of water-filled CNTs. It is observed that a longitudinal electric field enhances, but the transverse electric field reduces the elastic modulus and critical buckling stress of water-filled CNTs. The divergent effect of the electric field is attributed to the competition between the axial and circumferential pressures induced by polar water molecules. Furthermore, it is notable that the transverse electric field could result in an internal pressure with elliptical distribution, which is an effective and convenient approach to apply nonuniform pressure on nanochannels. Based on pre-strained water-filled CNTs, we designed a nanoscale trigger with an evident and rapid height change initiated by switching the direction of the electric field. The reported finding provides a foundation for an electricity-controlled property of nanochannels filled with polar molecules and provides an insight into the design of nanoscale functional devices.
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Affiliation(s)
- Hongfei Ye
- International Research Center for Computational Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024, People's Republic of China
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25
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Nikzad M, Azimian AR, Rezaei M, Nikzad S. Water liquid-vapor interface subjected to various electric fields: A molecular dynamics study. J Chem Phys 2017; 147:204701. [DOI: 10.1063/1.4985875] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mohammadreza Nikzad
- Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, 84181-48499 Khomeinishahr/Isfahan, Iran
| | - Ahmad Reza Azimian
- Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, 84181-48499 Khomeinishahr/Isfahan, Iran
| | - Majid Rezaei
- Mechanical Engineering Department, Isfahan University of Technology, 84156-8311 Isfahan, Iran
| | - Safoora Nikzad
- Department of Medical Physics, Hamadan University of Medical Sciences, 65176-19654 Hamadan, Iran
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Abstract
Force microscopy enables a variety of approaches to manipulate and/or modify surfaces. Few of those methods have evolved into advanced probe-based lithographies. Oxidation scanning probe lithography (o-SPL) is the only lithography that enables the direct and resist-less nanoscale patterning of a large variety of materials, from metals to semiconductors; from self-assembled monolayers to biomolecules. Oxidation SPL has also been applied to develop sophisticated electronic and nanomechanical devices such as quantum dots, quantum point contacts, nanowire transistors or mechanical resonators. Here, we review the principles, instrumentation aspects and some device applications of o-SPL. Our focus is to provide a balanced view of the method that introduces the key steps in its evolution, provides some detailed explanations on its fundamentals and presents current trends and applications. To illustrate the capabilities and potential of o-SPL as an alternative lithography we have favored the most recent and updated contributions in nanopatterning and device fabrication.
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28
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Cao Q, Li L, Huang F, Zuo C. Ion-Specific Effects on the Elongation Dynamics of a Nanosized Water Droplet in Applied Electric Fields. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:428-437. [PMID: 27996273 DOI: 10.1021/acs.langmuir.6b04101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report an all-atom molecular dynamics study of the structures and dynamics of salty water droplets on a silicon surface under the influence of applied electric field. Our simulation results support ion-specific effects on the elongation dynamics of salty nanodroplets, induced by the field. This feature has not been explored up to now in monovalent salts. Nevertheless, the importance of ion-specific effects is widely confirmed in biological and colloidal systems. In particular, the increase of salt concentration enhances the effect of the nature of ions on the wetting properties of droplets. In the presence of electric field (0.05 V Å-1), a complete spreading is implemented in a short time for different droplets at a concentration of 1 M, and the droplet morphology is stable, observed at long time scales. However, a higher salt concentration of 4 M considerably suppresses the spreading process owing to the increase of surface tension. It was found that the NaCl droplet shows deformation oscillations along the external field, but cannot fully wet the substrate surface. By contrast, the CsCl droplet reaches complete elongation rapidly and adopts a steady strip shape. The KCl droplet undergoes frequent transitions between breakup and connection. Additionally, the droplets can be elongated only when the electric field strength exceeds a threshold value. The dipole orientation of interfacial water and the ionic diffusion exhibit ion-specific dependences, but the hydrogen bond network is scarcely disturbed, excluding a concentration-dependent effect.
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Affiliation(s)
- Qianqian Cao
- College of Mechanical and Electrical Engineering, Jiaxing University , Jiaxing 314001, P.R. China
| | - Lujuan Li
- College of Mechanical and Electrical Engineering, Jiaxing University , Jiaxing 314001, P.R. China
| | - Fengli Huang
- College of Mechanical and Electrical Engineering, Jiaxing University , Jiaxing 314001, P.R. China
| | - Chuncheng Zuo
- College of Mechanical and Electrical Engineering, Jiaxing University , Jiaxing 314001, P.R. China
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29
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Chen J, Wang C, Wei N, Wan R, Gao Y. 3D flexible water channel: stretchability of nanoscale water bridge. NANOSCALE 2016; 8:5676-5681. [PMID: 26900012 DOI: 10.1039/c5nr08072j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Artificial water channels can contribute to a better understanding of natural water channels and offer a highly selective, advanced conductance system. Most studies use nanotubes, however it is difficult to fabricate a flexible structure, and the nanosized diameter brings nanoconfinement effects, and nanotube toxicity arouses biosafety concerns. In this paper, we use an electric field to restrain the water molecules to form a nanoscale water bridge as an artificial water channel to connect a separated solid plate by molecular dynamics simulations. We observe strong 3D flexible stretchability in the water bridge, maintaining a variable length and an arbitrary angle for a considerably long time. The stretching of the water bridge enables it to be polarized at an arbitrary angle and the stretchability is linearly dependent upon the polarization strength. More interestingly, we show the possibility of establishing complex water networks, e.g., triangle, rectangle, hexagon, and tetrahedron-tetrahedron water networks. Our results may help realize structurally flexible and environmentally friendly water channels for lab-on-a-chip applications in nanofluidics.
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Affiliation(s)
- Jige Chen
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
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30
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Xu Z, Wang C, Sheng N, Hu G, Zhou Z, Fang H. Manipulation of a neutral and nonpolar nanoparticle in water using a nonuniform electric field. J Chem Phys 2016; 144:014302. [PMID: 26747801 DOI: 10.1063/1.4939151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The manipulation of nanoparticles in water is of essential importance in chemical physics, nanotechnology, medical technology, and biotechnology applications. Generally, a particle with net charges or charge polarity can be driven by an electric field. However, many practical particles only have weak and even negligible charge and polarity, which hinders the electric field to exert a force large enough to drive these nanoparticles directly. Here, we use molecular dynamics simulations to show that a neutral and nonpolar nanoparticle in liquid water can be driven directionally by an external electric field. The directed motion benefits from a nonuniform water environment produced by a nonuniform external electric field, since lower water energies exist under a higher intensity electric field. The nanoparticle spontaneously moves toward locations with a weaker electric field intensity to minimize the energy of the whole system. Considering that the distance between adjacent regions of nonuniform field intensity can reach the micrometer scale, this finding provides a new mechanism of manipulating nanoparticles from the nanoscale to the microscale.
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Affiliation(s)
- Zhen Xu
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Chunlei Wang
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Nan Sheng
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Guohui Hu
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, Shanghai 200072, China
| | - Zhewei Zhou
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, Shanghai 200072, China
| | - Haiping Fang
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
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31
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Krivoshapkina Y, Kaestner M, Rangelow IW. Tip-based nanolithography methods and materials. MATERIALS AND PROCESSES FOR NEXT GENERATION LITHOGRAPHY 2016. [DOI: 10.1016/b978-0-08-100354-1.00015-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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32
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Lugli F, Toschi F, Biscarini F, Zerbetto F. Electric Field Effects on Short Fibrils of Aβ Amyloid Peptides. J Chem Theory Comput 2015; 6:3516-26. [PMID: 26617101 DOI: 10.1021/ct1001335] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amyloid fibrils are highly ordered protein aggregates, which are associated with many neurodegenerative diseases. The assembling dynamics of monomeric beta-amyloid peptides, Aβ, into small aggregates (and then into long fibrils) is still debated and has become a hot topic. In this study, we conducted molecular dynamics simulations in explicit water of small Aβ protofibrils (from monomer to pentamer) under the perturbation of an externally applied electric field with the aim of investigating the fundamental molecular interactions involved in the aggregation mechanism. Dynamics of small adducts of Aβ(16-42) in the presence of an electric field, which was shown before to accelerate the conformational change of a single molecule, indicate that the structural resilience increases with the number of molecules in the aggregate. In particular, for 50 ns, the pentamer shows an enhanced stability in secondary structure, number of hydrogen bonds, and number of salt bridges, even in the presence of the field perturbation. The resilience to the field perturbation is linked to the variation of the induced dipole moment of the aggregates that tends to level off very rapidly with the growing number of molecules, thereby reducing the energy available per molecule to produce structural changes. The results also show that in the presence of the field the stability of the hydrophobic second β-sheet (β2, residues 31-42) is higher than that of the first one (β1, residues 18-26). In particular, we identify Gly33, Gly37, and Met35 as the most important residues that stabilize the intermolecular packing and may act as nucleation sites for fibrillization. Furthermore, dynamics of the full-length Aβ(1-42) pentameric aggregate, which include the highly charged random coil residues 1-15, confirmed the key role of the second hydrophobic core in the protofibril structure.
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Affiliation(s)
- Francesca Lugli
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126 Bologna, Italy and ISMN CNR, V. Gobetti, Bologna, Italy
| | - Francesca Toschi
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126 Bologna, Italy and ISMN CNR, V. Gobetti, Bologna, Italy
| | - Fabio Biscarini
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126 Bologna, Italy and ISMN CNR, V. Gobetti, Bologna, Italy
| | - Francesco Zerbetto
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126 Bologna, Italy and ISMN CNR, V. Gobetti, Bologna, Italy
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33
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Hens A, Biswas G, De S. Evaporation of water droplets on Pt-surface in presence of external electric field—A molecular dynamics study. J Chem Phys 2015; 143:094702. [DOI: 10.1063/1.4929784] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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34
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Jirsák J, Moučka F, Škvor J, Nezbeda I. Aqueous electrolyte surfaces in strong electric fields: molecular insight into nanoscale jets and bridges. Mol Phys 2014. [DOI: 10.1080/00268976.2014.983199] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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35
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Garcia R, Knoll AW, Riedo E. Advanced scanning probe lithography. NATURE NANOTECHNOLOGY 2014; 9:577-87. [PMID: 25091447 DOI: 10.1038/nnano.2014.157] [Citation(s) in RCA: 252] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/04/2014] [Indexed: 05/24/2023]
Abstract
The nanoscale control afforded by scanning probe microscopes has prompted the development of a wide variety of scanning-probe-based patterning methods. Some of these methods have demonstrated a high degree of robustness and patterning capabilities that are unmatched by other lithographic techniques. However, the limited throughput of scanning probe lithography has prevented its exploitation in technological applications. Here, we review the fundamentals of scanning probe lithography and its use in materials science and nanotechnology. We focus on robust methods, such as those based on thermal effects, chemical reactions and voltage-induced processes, that demonstrate a potential for applications.
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Affiliation(s)
- Ricardo Garcia
- Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Inés de la Cruz 3. 28049 Madrid, Spain
| | - Armin W Knoll
- IBM Research - Zurich, Saeumerstr. 4, 8803 Rueschlikon, Switzerland
| | - Elisa Riedo
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
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36
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Kurra N, Reifenberger RG, Kulkarni GU. Nanocarbon-scanning probe microscopy synergy: fundamental aspects to nanoscale devices. ACS APPLIED MATERIALS & INTERFACES 2014; 6:6147-6163. [PMID: 24697666 DOI: 10.1021/am500122g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Scanning probe techniques scanning tunneling microscopy (STM) and atomic force microscopy (AFM) have emerged as unique local probes for imaging, manipulation, and modification of surfaces at the nanoscale. Exercising the fabrication of atomic and nansocale devices with desired properties have demanded rapid development of scanning probe based nanolithographies. Dip pen nanolithography (DPN) and local anodic oxidation (LAO) have been widely employed for fabricating functional patterns and prototype devices at nanoscale. This review discusses the progress in AFM bias lithography with focus on nanocarbon species on which many functional quantum device structures have been realized using local electrochemical and electrostatic processes. As water meniscus is central to AFM bias lithography, the meniscus formation, estimation and visualization is discussed briefly. A number of graphene-based nanodevices have been realized on the basis AFM bias lithography in the form of nanoribbons, nanorings and quantum dots with sufficiently small dimensions to show quantum phenomena such as conductance fluctuations. Several studies involving graphitic surfaces and carbon nanotubes are also covered. AFM based scratching technique is another promising approach for the fabrication of nanogap electrodes, important in molecular electronics.
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Affiliation(s)
- Narendra Kurra
- Chemistry and Physics of Materials Unit and DST Unit on Nanoscience, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur PO, Bangalore 560 064, India
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37
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Ostrowski JHJ, Eaves JD. The tunable hydrophobic effect on electrically doped graphene. J Phys Chem B 2014; 118:530-6. [PMID: 24328210 DOI: 10.1021/jp409342n] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using molecular dynamics simulations, we study the hydrophobic effect on electrically doped single layer graphene. With doping levels measured in volts, large changes in contact angle occur for modest voltages applied to the sheet. The effect can be understood as a renormalization of the surface tension between graphene and water in the presence of an electric field generated by the dopant charge, an entirely collective effect termed electrowetting. Because the electronic density of states scales linearly in the vicinity of the Fermi energy, the cosine of the contact angle scales quartically with the applied voltage rather than quadratically, as it would for a two-dimensional metal or in multiple layer graphene. While electrowetting explains the phenomenon, it does not account for the slight asymmetry observed in the hydrophobic response between n- and p-doping.
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Affiliation(s)
- Joseph H J Ostrowski
- Department of Chemistry and Biochemistry, 215 UCB, University of Colorado at Boulder , Boulder, Colorado 80309, United States
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38
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Rai D, Kulkarni AD, Gejji SP, Bartolotti LJ, Pathak RK. Exploring electric field induced structural evolution of water clusters, (H2O)n [n = 9–20]: Density functional approach. J Chem Phys 2013; 138:044304. [DOI: 10.1063/1.4776214] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Structure of the floating water bridge and water in an electric field. Proc Natl Acad Sci U S A 2012; 109:16463-8. [PMID: 23010930 DOI: 10.1073/pnas.1210732109] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The floating water bridge phenomenon is a freestanding rope-shaped connection of pure liquid water, formed under the influence of a high potential difference (approximately 15 kV). Several recent spectroscopic, optical, and neutron scattering studies have suggested that the origin of the bridge is associated with the formation of anisotropic chains of water molecules in the liquid. In this work, high energy X-ray diffraction experiments have been performed on a series of floating water bridges as a function of applied voltage, bridge length, and position within the bridge. The two-dimensional X-ray scattering data showed no direction-dependence, indicating that the bulk water molecules do not exhibit any significant preferred orientation along the electric field. The only structural changes observed were those due to heating, and these effects were found to be the same as for bulk water. These X-ray scattering measurements are supported by molecular dynamics (MD) simulations which were performed under electric fields of 10(6) V/m and 10(9) V/m. Directional structure factor calculations were made from these simulations parallel and perpendicular to the E-field. The 10(6) V/m model showed no significant directional-dependence (anisotropy) in the structure factors. The 10(9) V/m model however, contained molecules aligned by the E-field, and had significant structural anisotropy.
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40
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Morawetz K. Theory of water and charged liquid bridges. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:026302. [PMID: 23005849 DOI: 10.1103/physreve.86.026302] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2011] [Indexed: 06/01/2023]
Abstract
The phenomenon of liquid bridge formation due to an applied electric field is investigated. A solution of a charged catenary is presented, which allows one to determine the static and dynamical stability conditions where charged liquid bridges are possible. The creeping height, the bridge radius and length, as well as the shape of the bridge are calculated showing an asymmetric profile, in agreement with observations. The flow profile is calculated from the Navier-Stokes equation leading to a mean velocity, which combines charge transport with neutral mass flow and which describes recent experiments on water bridges.
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Affiliation(s)
- K Morawetz
- Münster University of Applied Science, Steinfurt, Germany
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41
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Daub CD, Cann NM. How Are Completely Desolvated Ions Produced in Electrospray Ionization: Insights from Molecular Dynamics Simulations. Anal Chem 2011; 83:8372-6. [DOI: 10.1021/ac202103p] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Christopher D. Daub
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6
| | - Natalie M. Cann
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6
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42
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Aerov AA. Why the water bridge does not collapse. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:036314. [PMID: 22060499 DOI: 10.1103/physreve.84.036314] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 05/26/2011] [Indexed: 05/31/2023]
Abstract
In 2007 an interesting phenomenon was discovered [J. Phys. D 40, 6112 (2007)]: a horizontal thread of water, the so-called water bridge, hangs in a horizontal electrostatic field. A different explanation of the water bridge stability is proposed herein: the force supporting it is the surface tension of water, while the role of the electric field is to not allow the water bridge to reduce its surface energy by breaking into separate drops. It is proven that electrostatic field is not the origin of the tension holding the bridge.
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Affiliation(s)
- Artem A Aerov
- Physics Department, Moscow State University, Moscow RU-119991, Russia
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43
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Abstract
AbstractThe formation of aqueous bridges containing phenol and ethylene glycol as well as bisphenol-A, hydrochinone and p-cresol under the application of high voltage DC (“liquid bridges”) is reported. Detailed studies were made for phenol and glycol with concentrations from 0.005 to 0.531 mol L−1. Conductivity as well as substance and mass transfers through these aqueous bridges are discussed and compared with pure water bridges. Previously suggested bidirectional mass transport is confirmed for the substances tested. Anodic oxidation happens more efficiently when phenol or glycol are transported from the cathode to the anode since in this case the formation of a passivation layer or electrode poisoning are retarded by the electrohydrodynamic (EHD) flow. The conductivity in the cathode beaker decreases in all experiments due to electrophoretic transport of naturally dissolved carbonate and bicarbonate to the anode. The observed electrochemical behavior is shortly discussed and compared to known mechanisms.
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44
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Venturini A, Zerbetto F. Dynamics of a lipid bilayer induced by electric fields. Phys Chem Chem Phys 2011; 13:9216-22. [DOI: 10.1039/c1cp20322c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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45
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Daub CD, Bratko D, Luzar A. Nanoscale Wetting Under Electric Field from Molecular Simulations. MULTISCALE MOLECULAR METHODS IN APPLIED CHEMISTRY 2011; 307:155-79. [DOI: 10.1007/128_2011_188] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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46
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Saija F, Aliotta F, Fontanella ME, Pochylski M, Salvato G, Vasi C, Ponterio RC. Communication: An extended model of liquid bridging. J Chem Phys 2010; 133:081104. [DOI: 10.1063/1.3483690] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Boyle MG, Mitra J, Dawson P. The tip-sample water bridge and light emission from scanning tunnelling microscopy. NANOTECHNOLOGY 2009; 20:335202. [PMID: 19636103 DOI: 10.1088/0957-4484/20/33/335202] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The light emission spectrum from a scanning tunnelling microscope (LESTM) is investigated as a function of relative humidity and shown to provide a novel and sensitive means for probing the growth and properties of a water meniscus on the nanometre scale. An empirical model of the light emission process is formulated and applied successfully to replicate the decay in light intensity and spectral changes observed with increasing relative humidity. The modelling indicates a progressive water filling of the tip-sample junction with increasing humidity or, more pertinently, of the volume of the localized surface plasmons responsible for light emission; it also accounts for the effect of asymmetry in structuring of the water molecules with respect to the polarity of the applied bias. This is juxtaposed with the case of a non-polar liquid in the tip-sample nanocavity where no polarity dependence of the light emission is observed. In contrast to the discrete detection of the presence/absence of a water bridge in other scanning probe experiments through measurement of the feedback parameter for instrument control, LESTM offers a means of continuously monitoring the development of the water bridge with sub-nanometre sensitivity. The results are relevant to applications such as dip-pen nanolithography and electrochemical scanning probe microscopy.
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Affiliation(s)
- Michael G Boyle
- Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University, Belfast BT71NN, UK
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49
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Choi H, Kim J, Hong S, Ha M, Jang J. Molecular simulation of the nanoscale water confined between an atomic force microscope tip and a surface. MOLECULAR SIMULATION 2009. [DOI: 10.1080/08927020802635129] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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50
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Hu Z, Jiang J. Electrophoresis in protein crystal: nonequilibrium molecular dynamics simulations. Biophys J 2008; 95:4148-56. [PMID: 18641079 PMCID: PMC2567938 DOI: 10.1529/biophysj.108.140160] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2008] [Accepted: 07/08/2008] [Indexed: 11/18/2022] Open
Abstract
Electrophoresis of a mixture of NaCl and CaCl2 in a lysozyme crystal is investigated using nonequilibrium molecular dynamics (MD) simulations. Upon exposure to an electric field, the stability of lysozyme is found to decrease slightly. This finding is demonstrated by increases in the root mean-square deviations of the heavy atoms of lysozyme, in the solvent-accessible surface area of hydrophobic residues, and in the number of hydrogen bonds between lysozyme and water. The solvent-accessible surface area of hydrophilic residues changes marginally, and the number of hydrogen bonds between lysozyme molecules decreases. Water molecules tend to align preferentially parallel to the electric field, and the dipole moment along the pore axis increases linearly with increasing field strength. Two pronounced layered structures are observed for Na+ and Ca2+ in the vicinity of protein surface, but only one enriched layer is observed for Cl-. The number distributions of all ions are nearly independent of the electric field. The water coordination numbers of all ions are smaller in the crystal than in aqueous bulk solution; however, the reverse is found for the Cl- coordination numbers of cations. Both the water and the Cl- coordination numbers are insensitive to the electric field. Ion diffusivities in the crystal are approximately 2 orders of magnitude smaller than those in aqueous bulk solution. The drift velocities of ions increase proportionally to the electric field, particularly at high strengths, and depend on ionic charge and coordination with oppositely charged ions. Electrical current exhibits a linear relationship with the field strength. The zero-field electrical conductivity is estimated to be 0.56 S/m, which is very close to 0.61 S/m as predicted by the Nernst-Einstein equation.
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Affiliation(s)
- Zhongqiao Hu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117576
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