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Rodriguez C, Torres-Costa V, Bittner A, Morin S, Cascajo Castresana M, Chiriaev S, Modin E, Chuvilin A, Manso Silván M. Electron microscopy approach to the wetting dynamics of single organosilanized mesopores. iScience 2023; 26:107981. [PMID: 37860771 PMCID: PMC10583112 DOI: 10.1016/j.isci.2023.107981] [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: 12/30/2022] [Revised: 09/08/2023] [Accepted: 09/16/2023] [Indexed: 10/21/2023] Open
Abstract
Columnar mesoporous silicon (PSi) with hydrophobic vs. hydrophilic chemistries was chosen as a model for the local (pore-by-pore) study of water-pore interactions. Tomographic reconstructions provided a 3D view of the ramified pore structure. An in situ study of PSi wetting was conducted for categorized pore diameters by environmental scanning TEM. An appropriate setting of the contrast allows for the normalization of the gray scale in the images as a function of relative humidity (RH). This allows constructing an isotherm for each single pore and a subsequent averaging provides an isotherm for each pore size range. The isotherms systematically point to an initial adsorption through the formation of water adlayers, followed by a capillary filling process at higher RH. The local isotherms correlate with (global) gravimetric determination of wetting. Our results point at the validation of a technique for the study of aging and stability of single-pore nanoscale devices.
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Affiliation(s)
- C. Rodriguez
- Departamento de Física Aplicada, Centro de Microanálisis de Materiales and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Mecwins, Roda de Poniente 15, Tres Cantos, Madrid 28760, Spain
| | - V. Torres-Costa
- Departamento de Física Aplicada, Centro de Microanálisis de Materiales and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - A.M. Bittner
- CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
| | - S. Morin
- CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
- Department of Chemistry, York University, 4700 Keele Street, Toronto M3J 1P3, Canada
| | - M. Cascajo Castresana
- CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
- Tecnalia, 20009 Donostia-San Sebastián, Spain
| | - S. Chiriaev
- Mads Clausen Institute, University of Southern Denmark, 6400 Sønderborg, Denmark
| | - E. Modin
- CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
| | - A. Chuvilin
- CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
| | - M. Manso Silván
- Departamento de Física Aplicada, Centro de Microanálisis de Materiales and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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2
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Li M, Zhao Y, Bian S, Qiao J, Hu X, Yu S. A green, environment-friendly, high-consolidation-strength composite dust suppressant derived from xanthan gum. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:7489-7502. [PMID: 34476699 DOI: 10.1007/s11356-021-16258-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
To solve issues of low consolidation strength, poor dust suppression effect, and secondary pollution of the current coal dust suppressors, a greener and higher-consolidation-strength composite dust suppressor was synthesized by the radical polymerization of xanthan gum (XG) as the graft substrate, methyl acrylate (MA), and vinyl acetate (VAc) as the graft monomers. Taking compressive strength as the main optimization index and viscosity and surface tension as the secondary indices, the optimum ratio of MA:VAc was 3:5 and the optimum solid content was 2%. Experiments reveal that the prepared dust suppressant can naturally infiltrate into coal to form a hard solidified layer. At a wind speed of 10 m/s, the solidified layer still maintained structural integrity, indicating that the dust suppressant exhibits a good dust fixation effect. The dust suppressant can not only maintain relatively stable performance for a period of time but also degrade naturally. Furthermore, molecular dynamics simulation reveals not only the interaction mechanism between coal molecules and the dust suppressor but also the wetting mechanism of the dust suppressor. Experimental and simulation results reveal that as a multifunctional dust suppressor with excellent performance, the as-prepared dust suppressor demonstrates the immense potential for the control of coal dust. Graphical abstract.
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Affiliation(s)
- Miaomiao Li
- College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Yanyun Zhao
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China.
| | - Susu Bian
- College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Jian Qiao
- College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Xiangming Hu
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
- Key Lab of Mine Disaster Prevention and Control, College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China
| | - Shijian Yu
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China.
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3
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Zhou G, Liu C, Bumm LA, Huang L. Force Field Parameter Development for the Thiolate/Defective Au(111) Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4098-4107. [PMID: 32200638 DOI: 10.1021/acs.langmuir.0c00530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A molecular-level understanding of the interplay between self-assembled monolayers (SAMs) of thiolates and gold surface is of great importance to a wide range of applications in surface science and nanotechnology. Despite theoretical research progress of the past decade, an atomistic model, capable of describing key features of SAMs at reconstructed gold surfaces, is still missing. In this work, periodic ab initio density functional theory (DFT) calculations were utilized to develop a new atomistic force field model for alkanethiolate (AT) SAMs on a reconstructed Au(111) surface. The new force field parameters were carefully trained to reproduce the key features, including vibrational spectra and torsion energy profiles of ethylthiolate (C2S) in the bridge or staple motif model on the Au(111) surface, wherein, the force constants of the bond and angle terms were trained by matching the vibrational spectra, while the torsion parameters of the dihedral angles were trained via fitting the torsion energy profiles from DFT calculations. To validate the developed force field parameters, we performed classical molecular dynamics (MD) simulations for both pristine and reconstructed Au-S interface models with a (2√3 × 3) unit cell, which includes four dodecanethiolate (C10S) molecules on the Au(111) surface. The simulation results showed that the geometrical features of the investigated Au-S interface models and structural properties of the C10S SAMs are in good agreement with the ab initio MD studies. The newly developed atomistic force field model provides new fundamental insights into AT SAMs on the reconstructed Au(111) surface and adds advancement to the existing interface research knowledge.
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Affiliation(s)
- Guobing Zhou
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Chang Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009, China
| | - Lloyd A Bumm
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Liangliang Huang
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States
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4
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Liu D, Li Y, Liu F, Zhou W, Sun A, Liu X, Chen F, Xu BB, Wei J. Interfacial Interaction Enhanced Rheological Behavior in PAM/CTAC/Salt Aqueous Solution-A Coarse-Grained Molecular Dynamics Study. Polymers (Basel) 2020; 12:polym12020265. [PMID: 31991789 PMCID: PMC7077399 DOI: 10.3390/polym12020265] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 01/19/2020] [Accepted: 01/21/2020] [Indexed: 11/16/2022] Open
Abstract
Interfacial interactions within a multi-phase polymer solution play critical roles in processing control and mass transportation in chemical engineering. However, the understandings of these roles remain unexplored due to the complexity of the system. In this study, we used an efficient analytical method-a nonequilibrium molecular dynamics (NEMD) simulation-to unveil the molecular interactions and rheology of a multiphase solution containing cetyltrimethyl ammonium chloride (CTAC), polyacrylamide (PAM), and sodium salicylate (NaSal). The associated macroscopic rheological characteristics and shear viscosity of the polymer/surfactant solution were investigated, where the computational results agreed well with the experimental data. The relation between the characteristic time and shear rate was consistent with the power law. By simulating the shear viscosity of the polymer/surfactant solution, we found that the phase transition of micelles within the mixture led to a non-monotonic increase in the viscosity of the mixed solution with the increase in concentration of CTAC or PAM. We expect this optimized molecular dynamic approach to advance the current understanding on chemical-physical interactions within polymer/surfactant mixtures at the molecular level and enable emerging engineering solutions.
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Affiliation(s)
- Dongjie Liu
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (D.L.); (W.Z.)
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;
| | - Yong Li
- Drilling and Production Engineering Research Institute, Chuanqing Drilling and Exploration Engineering Company Ltd., CNPC, Xi’an 710018, China;
| | - Fei Liu
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;
| | - Wenjing Zhou
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (D.L.); (W.Z.)
| | - Ansu Sun
- Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK; (A.S.); (X.L.)
| | - Xiaoteng Liu
- Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK; (A.S.); (X.L.)
| | - Fei Chen
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (D.L.); (W.Z.)
- Correspondence: (F.C.); (B.B.X.); (J.W.); Tel.: +86-029-82664375 (J.W.)
| | - Ben Bin Xu
- Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK; (A.S.); (X.L.)
- Correspondence: (F.C.); (B.B.X.); (J.W.); Tel.: +86-029-82664375 (J.W.)
| | - Jinjia Wei
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (D.L.); (W.Z.)
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;
- Correspondence: (F.C.); (B.B.X.); (J.W.); Tel.: +86-029-82664375 (J.W.)
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5
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Liu D, Liu F, Zhou W, Chen F, Wei J. Molecular dynamics simulation of self-assembly and viscosity behavior of PAM and CTAC in salt-added solutions. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.07.053] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Li X, Zhu L, Xue Q, Chang X, Ling C, Xing W. Superior Selective CO 2 Adsorption of C 3N Pores: GCMC and DFT Simulations. ACS APPLIED MATERIALS & INTERFACES 2017; 9:31161-31169. [PMID: 28832119 DOI: 10.1021/acsami.7b09648] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Development of high-performance sorbents is extremely significant for CO2 capture due to its increasing atmospheric concentration and impact on environmental degradation. In this work, we develop a new model of C3N pores based on GCMC calculations to describe its CO2 adsorption capacity and selectivity. Remarkably, it exhibits an outstanding CO2 adsorption capacity and selectivity. For example, at 0.15 bar it shows exceptionally high CO2 uptakes of 3.99 and 2.07 mmol/g with good CO2/CO, CO2/H2, and CO2/CH4 selectivity at 300 and 350 K, separately. More importantly, this adsorbent also shows better water stability. Specifically, its CO2 uptakes are 3.80 and 5.91 mmol/g for and 0.15 and 1 bar at 300 K with a higher water content. Furthermore, DFT calculations demonstrate that the strong interactions between C3N pores and CO2 molecules contribute to its impressive CO2 uptake and selectivity, indicating that C3N pores can be an extremely promising candidate for CO2 capture.
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Affiliation(s)
- Xiaofang Li
- State Key Laboratory of Heavy Oil Processing and ‡College of Science, China University of Petroleum , Qingdao 266555, Shandong, People's Republic of China
| | - Lei Zhu
- State Key Laboratory of Heavy Oil Processing and ‡College of Science, China University of Petroleum , Qingdao 266555, Shandong, People's Republic of China
| | - Qingzhong Xue
- State Key Laboratory of Heavy Oil Processing and ‡College of Science, China University of Petroleum , Qingdao 266555, Shandong, People's Republic of China
| | - Xiao Chang
- State Key Laboratory of Heavy Oil Processing and ‡College of Science, China University of Petroleum , Qingdao 266555, Shandong, People's Republic of China
| | - Cuicui Ling
- State Key Laboratory of Heavy Oil Processing and ‡College of Science, China University of Petroleum , Qingdao 266555, Shandong, People's Republic of China
| | - Wei Xing
- State Key Laboratory of Heavy Oil Processing and ‡College of Science, China University of Petroleum , Qingdao 266555, Shandong, People's Republic of China
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7
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Zhang L, Liu L. Polymeric Self-Assembled Monolayers Anomalously Improve Thermal Transport across Graphene/Polymer Interfaces. ACS APPLIED MATERIALS & INTERFACES 2017; 9:28949-28958. [PMID: 28766936 DOI: 10.1021/acsami.7b09605] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ultralow thermal conductivities of bulk polymers greatly limit their applications in areas demanding fast heat dissipation, such as flexible electronics and microelectronics. Therefore, polymeric composites incorporating highly thermally conductive filler materials (e.g., graphene and carbon nanotubes) have been produced to address the issue. However, despite some enhancement, thermal conductivities of these materials are still far below theoretical predictions, mainly due to the inefficient thermal transport across material interfaces. Here, using molecular dynamics simulations, we demonstrate that polyethylene (PE) self-assembled monolayer (SAM) functionalized graphene surfaces at a high grafting density can drastically improve interfacial thermal conduction between graphene and the matrix of poly(methyl methacrylate) (PMMA). In contrast to abrupt temperature drop across pristine graphene/PMMA interfaces, temperature field in the vicinity of a PE-grafted graphene/PMMA interface is continuous with a smoother transition and higher thermal conductance. This anomalous improvement is attributed to three factors that closely relate to the grafting density of the SAM of PE. First, the SAM with high grafting densities features highly extended chains that enhance along-chain thermal conduction. Second, the strong covalent bonding between the SAM and the graphene facilitates heat transfer at their joints. Third, the SAM and the PMMA matrix are both organic materials, leading to enhanced interfacial vibrational coupling. Molecular mechanisms underpinning these phenomena are systematically elucidated by analyzing the temperature field, density distribution, Herman's orientation factor, the vibrational density of states, cumulative correlation factor, the integrated autocorrelation of interfacial heat power, and interfacial adhesion. All results suggest the incorporation of SAMs at a high grafting density or extremely extended polymer brushes for drastically improved interfacial thermal transport between hard and soft materials toward a wide range of applications.
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Affiliation(s)
- Lin Zhang
- Department of Mechanical and Aerospace Engineering, Utah State University , Logan, Utah 84322, United States
| | - Ling Liu
- Department of Mechanical and Aerospace Engineering, Utah State University , Logan, Utah 84322, United States
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8
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Cheng G, Liao M, Zhao D, Zhou J. Molecular Understanding on the Underwater Oleophobicity of Self-Assembled Monolayers: Zwitterionic versus Nonionic. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1732-1741. [PMID: 28122450 DOI: 10.1021/acs.langmuir.6b03988] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Molecular dynamics simulations are conducted to investigate the underwater oleophobicity of self-assembled monolayers (SAMs) with different head groups. Simulation results show that the order of underwater oleophobicity of SAMs is methyl < amide < oligo(ethylene glycol) (OEG) < ethanolamine (ETA) < hydroxyl < mixed-charged zwitterionic. The underwater-oil contact angles (OCAs) are <133° for all nonionic hydrophilic SAMs, while the mixed-charged zwitterionic SAMs are underwater superoleophobic (OCA can reach 180°). It appears that surfaces with stronger underwater oleophobicity have better antifouling performance. Further study on the effect of different alkyl ammonium ions on mixed-charged SAMs reveals that the underwater OCAs are >143.6° for all SAMs; mixed-charged SAMs containing primary alkyl ammonium ion are likely to possess the best underwater oleophobicity for its strong hydration capacity. It seems that alkyl sulfonate anion (SO3-) is more hydrophilic than alkyl trimethylammonium ion (NC3+) for the hydrophobic methyl groups on nitrogen atoms and that the hydration of SO3- in mixed-charged SAMs can be seriously blocked by NC3+. The monomer of SO3- should be slightly longer than that of NC3+ to obtain better underwater oleophobicity in NC3+-/SO3--SAMs. In addition, the underwater oleophobicity of SAMs might become worse at low grafting densities. This work systematically proves that a zwitterionic surface is more underwater oleophobic than a nonionic surface. These results will help for the design and development of superoleophobic surfaces.
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Affiliation(s)
- Gang Cheng
- School of Chemistry and Chemical Engineering, Guangdong Provincial Key Laboratory for Green Chemical Product Technology, South China University of Technology , Guangzhou 510640, China
| | - Mingrui Liao
- School of Chemistry and Chemical Engineering, Guangdong Provincial Key Laboratory for Green Chemical Product Technology, South China University of Technology , Guangzhou 510640, China
| | - Daohui Zhao
- School of Chemistry and Chemical Engineering, Guangdong Provincial Key Laboratory for Green Chemical Product Technology, South China University of Technology , Guangzhou 510640, China
| | - Jian Zhou
- School of Chemistry and Chemical Engineering, Guangdong Provincial Key Laboratory for Green Chemical Product Technology, South China University of Technology , Guangzhou 510640, China
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Guo P, Tu Y, Yang J, Wang C, Sheng N, Fang H. Water-COOH Composite Structure with Enhanced Hydrophobicity Formed by Water Molecules Embedded into Carboxyl-Terminated Self-Assembled Monolayers. PHYSICAL REVIEW LETTERS 2015; 115:186101. [PMID: 26565476 DOI: 10.1103/physrevlett.115.186101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Indexed: 06/05/2023]
Abstract
By combining molecular dynamics simulations and quantum mechanics calculations, we show the formation of a composite structure composed of embedded water molecules and the COOH matrix on carboxyl-terminated self-assembled monolayers (COOH SAMs) with appropriate packing densities. This composite structure with an integrated hydrogen bond network inside reduces the hydrogen bonds with the water above. This explains the seeming contradiction on the stability of the surface water on COOH SAMs observed in experiments. The existence of the composite structure at appropriate packing densities results in the two-step distribution of contact angles of water droplets on COOH SAMs, around 0° and 35°, which compares favorably to the experimental measurements of contact angles collected from forty research articles over the past 25 years. These findings provide a molecular-level understanding of water on surfaces (including surfaces on biomolecules) with hydrophilic functional groups.
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Affiliation(s)
- Pan Guo
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yusong Tu
- College of Physics Science and Technology, Yangzhou University, Jiangsu 225009, China
| | - Jinrong Yang
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, 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
| | - 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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10
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Šolc R, Tunega D, Gerzabek MH, Woche SK, Bachmann J. Wettability of organically coated tridymite surface – molecular dynamics study. PURE APPL CHEM 2015. [DOI: 10.1515/pac-2014-1103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractClassical molecular dynamics (MD) study was performed in order to explain a different wettability of silanized silica-glass surfaces prepared by using two different precursors – dichlorodimethylsilane (DCDMS) and dimethyldiethoxysilane (DMDES), respectively. Whereas the modified surface prepared by DCDMS becomes hydrophobic (contact angle (CA) of water >90°), DMDES-modified surface stays partially hydrophilic (CA ∼39°). In order to explain the observed discrepancy, several models of surfaces of trydimite with different coating by (CH3)2–Si= units were constructed and treated by water nanodroplets in the MD simulations. The models of surfaces differ by a different degree of surface coverage and/or oligomerized (CH3)2–Si= units in a lateral dimension. The simulations showed that incomplete coverage leads to a decrease of the computed CA, whereas upon lateral oligomerization the CA increases. This variation of the CA is directly related to the accessible amount of the hydroxyl groups on the surfaces and can be a possible explanation of the difference in wettability between DCDMS- and DMDES-treated glass surfaces.
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Affiliation(s)
- Roland Šolc
- 1Institute of Soil Research, University of Natural Resources and Life Sciences, Peter-Jordan-Strasse 82, A-1190 Vienna, Austria
| | - Daniel Tunega
- 1Institute of Soil Research, University of Natural Resources and Life Sciences, Peter-Jordan-Strasse 82, A-1190 Vienna, Austria
| | - Martin H. Gerzabek
- 1Institute of Soil Research, University of Natural Resources and Life Sciences, Peter-Jordan-Strasse 82, A-1190 Vienna, Austria
| | - Susanne K. Woche
- 2Institute of Soil Science, Leibniz University Hannover, Herrenhäuser-Strasse 2, 30419 Hannover, Germany
| | - Jörg Bachmann
- 2Institute of Soil Science, Leibniz University Hannover, Herrenhäuser-Strasse 2, 30419 Hannover, Germany
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11
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Ramírez-Gutiérrez D, Nieto-Draghi C, Pannacci N, Castro LV, Álvarez-Ramírez F, Creton B. Surface photografting of acrylic acid on poly(dimethylsiloxane). Experimental and dissipative particle dynamics studies. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:1400-1409. [PMID: 25558765 DOI: 10.1021/la503694h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This work includes both experimental and theoretical studies of the wetting property changes of water on a surface of poly(dimethylsiloxane) (PDMS) modified with different amounts of acrylic acid (AA). The default surface properties of PDMS were changed from hydrophobic to hydrophilic behavior which was characterized with contact angle measurements by two approaches: (i) experimental tests of samples subjected to a photografting polymerization procedure to obtain a functionalized surface and (ii) DPD (dissipative particle dynamics) simulations which also involve the calculation of sets of repulsive parameters determined following two methods: the use of the "Blends" module in the Materials Studio software and the calculation of cohesive energy density with molecular simulations. Changes of contact angle values observed from both experimental and numerical simulation results provide qualitative and quantitative information on the wetting behavior of photografted surfaces.
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12
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Zhang J, Li W, Yan Y, Wang Y, Liu B, Shen Y, Chen H, Liu L. Molecular insight into nanoscale water films dewetting on modified silica surfaces. Phys Chem Chem Phys 2015; 17:451-8. [DOI: 10.1039/c4cp04554h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In this work, molecular dynamics simulations are adopted to investigate the microscopic dewetting mechanism of nanoscale water films on methylated silica surfaces.
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Affiliation(s)
- Jun Zhang
- College of Science
- China University of Petroleum
- 266580 Qingdao
- People's Republic of China
- Key Laboratory of New Energy Physics & Materials Science in Universities of Shandong
| | - Wen Li
- College of Science
- China University of Petroleum
- 266580 Qingdao
- People's Republic of China
- Key Laboratory of New Energy Physics & Materials Science in Universities of Shandong
| | - Youguo Yan
- College of Science
- China University of Petroleum
- 266580 Qingdao
- People's Republic of China
- Key Laboratory of New Energy Physics & Materials Science in Universities of Shandong
| | - Yefei Wang
- School of Petroleum Engineering
- China University of Petroleum
- 266580 Qingdao
- People's Republic of China
| | - Bing Liu
- College of Science
- China University of Petroleum
- 266580 Qingdao
- People's Republic of China
- Key Laboratory of New Energy Physics & Materials Science in Universities of Shandong
| | - Yue Shen
- College of Science
- China University of Petroleum
- 266580 Qingdao
- People's Republic of China
- Key Laboratory of New Energy Physics & Materials Science in Universities of Shandong
| | - Haixiang Chen
- College of Science
- China University of Petroleum
- 266580 Qingdao
- People's Republic of China
- Key Laboratory of New Energy Physics & Materials Science in Universities of Shandong
| | - Liang Liu
- College of Science
- China University of Petroleum
- 266580 Qingdao
- People's Republic of China
- Key Laboratory of New Energy Physics & Materials Science in Universities of Shandong
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13
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Peng C, Liu J, Zhao D, Zhou J. Adsorption of hydrophobin on different self-assembled monolayers: the role of the hydrophobic dipole and the electric dipole. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:11401-11. [PMID: 25185838 DOI: 10.1021/la502595t] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In this work, the adsorptions of hydrophobin (HFBI) on four different self-assembled monolayers (SAMs) (i.e., CH3-SAM, OH-SAM, COOH-SAM, and NH2-SAM) were investigated by parallel tempering Monte Carlo and molecular dynamics simulations. Simulation results indicate that the orientation of HFBI adsorbed on neutral surfaces is dominated by a hydrophobic dipole. HFBI adsorbs on the hydrophobic CH3-SAM through its hydrophobic patch and adopts a nearly vertical hydrophobic dipole relative to the surface, while it is nearly horizontal when adsorbed on the hydrophilic OH-SAM. For charged SAM surfaces, HFBI adopts a nearly vertical electric dipole relative to the surface. HFBI has the narrowest orientation distribution on the CH3-SAM, and thus can form an ordered monolayer and reverse the wettability of the surface. For HFBI adsorption on charged SAMs, the adsorption strength weakens as the surface charge density increases. Compared with those on other SAMs, a larger area of the hydrophobic patch is exposed to the solution when HFBI adsorbs on the NH2-SAM. This leads to an increase of the hydrophobicity of the surface, which is consistent with the experimental results. The binding of HFBI to the CH3-SAM is mainly through hydrophobic interactions, while it is mediated through a hydration water layer near the surface for the OH-SAM. For the charged SAM surfaces, the adsorption is mainly induced by electrostatic interactions between the charged surfaces and the oppositely charged residues. The effect of a hydrophobic dipole on protein adsorption onto hydrophobic surfaces is similar to that of an electric dipole for charged surfaces. Therefore, the hydrophobic dipole may be applied to predict the probable orientations of protein adsorbed on hydrophobic surfaces.
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Affiliation(s)
- Chunwang Peng
- School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology , Guangzhou, Guangdong 510640, P. R. China
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Zhang P, Xu Z, Liu Q, Yuan S. Mechanism of oil detachment from hybrid hydrophobic and hydrophilic surface in aqueous solution. J Chem Phys 2014; 140:164702. [DOI: 10.1063/1.4870930] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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15
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Vasumathi V, Cordeiro MND. Molecular dynamics study of mixed alkanethiols covering a gold surface at three different arrangements. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.03.064] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Li E, Du Z, Yuan S. Properties of a water layer on hydrophilic and hydrophobic self-assembled monolayer surfaces: A molecular dynamics study. Sci China Chem 2013. [DOI: 10.1007/s11426-013-4835-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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17
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Zhang C, Du C, Yan H, Yuan S, Chi L. Influence of self-assembled monolayers on the growth and crystallization of rubrene films: a molecular dynamics study. RSC Adv 2013. [DOI: 10.1039/c3ra41085d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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Pertsin A, Grunze M. Computer simulation of adhesion between hydrophilic and hydrophobic self-assembled monolayers in water. J Chem Phys 2012; 137:054701. [PMID: 22894365 DOI: 10.1063/1.4739745] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The grand canonical Monte Carlo technique and atomistic force fields are used to calculate the force-distance relations and free energies of adhesion between carboxyl and methyl terminated alkanethiolate self-assembled monolayers (SAMs) in water. Both symmetric and asymmetric confinements are considered, as formed by like and unlike SAMs, respectively. As the confinement is increased, water confined by the hydrophobic methyl terminated SAMs experiences capillary evaporation. As a consequence, the adhesion energy is determined by the direct interaction between bare SAMs. In the asymmetric system, an incomplete capillary evaporation is observed, with the number of water molecules dropped by more than an order of magnitude. The remaining water molecules are all adsorbed on the hydrophilic SAM, while the hydrophobic SAM is separated from the rest of the system by a thin vapor layer. The calculated free energies of adhesion are in acceptable agreement with experiment.
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Affiliation(s)
- Alexander Pertsin
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany.
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Wang H, Zhang H, Liu C, Yuan S. Coarse-grained molecular dynamics simulation of self-assembly of polyacrylamide and sodium dodecylsulfate in aqueous solution. J Colloid Interface Sci 2012; 386:205-11. [DOI: 10.1016/j.jcis.2012.07.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 07/03/2012] [Accepted: 07/04/2012] [Indexed: 10/28/2022]
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Electrochemical characterization of Self-assembled Monolayers (SAMs) of silanes on indium tin oxide (ITO) electrodes – Tuning electron transfer behaviour across electrode–electrolyte interface. J Colloid Interface Sci 2012; 374:241-9. [DOI: 10.1016/j.jcis.2012.02.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 01/18/2012] [Accepted: 02/06/2012] [Indexed: 01/04/2023]
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James M, Ciampi S, Darwish TA, Hanley TL, Sylvester SO, Gooding JJ. Nanoscale water condensation on click-functionalized self-assembled monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:10753-10762. [PMID: 21780835 DOI: 10.1021/la202359c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have examined the nanoscale adsorption of molecular water under ambient conditions onto a series of well-characterized functionalized surfaces produced by Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC or "click") reactions on alkyne-terminated self-assembled monolayers on silicon. Water contact angle (CA) measurements reveal a range of macroscopic hydrophilicity that does not correlate with the tendency of these surfaces to adsorb water at the molecular level. X-ray reflectometry has been used to follow the kinetics of water adsorption on these "click"-functionalized surfaces, and also shows that dense continuous molecular water layers are formed over 30 h. For example, a highly hydrophilic surface, functionalized by an oligo(ethylene glycol) moiety (with a CA = 34°) showed 2.9 Å of adsorbed water after 30 h, while the almost hydrophobic underlying alkyne-terminated monolayer (CA = 84°) showed 5.6 Å of adsorbed water over the same period. While this study highlights the capacity of X-ray reflectometry to study the structure of adsorbed water on these surfaces, it should also serve as a warning for those intending to characterize self-assembled monolayers and functionalized surfaces to avoid contamination by even trace amounts of water vapor. Moreover, contact angle measurements alone cannot be relied upon to predict the likely degree of moisture uptake on such surfaces.
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Affiliation(s)
- Michael James
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC NSW 2232, Australia.
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