46 results on '"Songqing Hu"'
Search Results
2. Degradation of Methyl Orange by ultrasonic Fenton-like process with Fe-based amorphous alloy powders
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Ling Tan, Xiaoyan Wang, Shaoke Wang, Xiaorui Qin, Linfeng Xiao, Chunling Li, Shuangqing Sun, and Songqing Hu
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Materials Chemistry ,General Chemistry ,Catalysis - Abstract
Fe-based amorphous alloy (FAA) is considered to be a new type of wastewater treatment catalyst. In this paper, the degradation performance of Fe-Nb-Cu-Si-B amorphous alloy powders to methyl orange (MO)...
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- 2023
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3. Top-down and matchable interfacial engineering to construct hierarchical deformed NiS/NiCoP for hydrogen evolution reaction over a broad pH range
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Xiaoyan Wang, Meng Cheng, Zihao Chen, Zhikun Wang, Chunling Li, Shuangqing Sun, and Songqing Hu
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General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2023
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4. Effect of hydrophobically modified SiO2 nanoparticles on the stability of water-based SDS foam
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Yan Wang, Xiyu Zhao, Jianhui Luo, Hongbing Wang, Shuangqing Sun, Songqing Hu, and Chunling Li
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Chemistry ,General Chemical Engineering ,Nanoparticle ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,SiO2 nanoparticles ,0104 chemical sciences ,Surface tension ,lcsh:Chemistry ,Molecular dynamics ,chemistry.chemical_compound ,Adsorption ,Pulmonary surfactant ,Chemical engineering ,lcsh:QD1-999 ,Surfactant ,Zeta potential ,Molecule ,lipids (amino acids, peptides, and proteins) ,Sodium dodecyl sulfate ,Foam stability ,0210 nano-technology - Abstract
In the present study, SiO2 nanoparticles were first hydrophobically modified and then added into anionic surfactant sodium dodecyl sulfate (SDS) stabilized water-based foam to improve the foam stability. The foam stability was experimentally evaluated by measuring surface tension, Zeta potential and half-life of the foam. The foam stabilizing mechanism was also studied from a micro perspective by molecular dynamics simulation through analyzing the equilibration configuration and MSD curve of both SDS surfactant and water molecules. The results show that foam exhibits an optimal stability when SiO2 concentration is 0.35 wt% under a specific surfactant concentration (0.5 wt%) in this work. The addition of SiO2 nanoparticles with suitable concentration could improve the adsorption between SDS molecules and nanoparticles, thus limiting the movement of SDS and restricting the movement of surrounding water molecules, which is beneficial to enhance the foam stability.
- Published
- 2020
5. Engineering the pore environment of metal–organic framework membranes via modification of the secondary building unit for improved gas separation
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Lili Fan, Yang Feng, Zhikun Wang, Zixi Kang, Shou Feng, Songqing Hu, Weidong Fan, and Daofeng Sun
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Materials science ,Renewable Energy, Sustainability and the Environment ,02 engineering and technology ,General Chemistry ,Microporous material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Membrane technology ,Membrane ,Chemical engineering ,Molecule ,General Materials Science ,Metal-organic framework ,Gas separation ,Solubility ,0210 nano-technology ,Selectivity - Abstract
The designability and adjustability of the pore structure are vital advantages of metal–organic framework (MOF) materials for separation. Their exploration in the field of membrane separation is still inadequate, especially for the regulation of the pore environment based on the inorganic secondary building unit (SBU). In this work, we have studied the effect of the pore environment regulated by the SBU on the gas separation performance of MOF membranes for the first time. The Fe3(μ3-O)(CH3COO)6 SBU of the parent framework (soc-MOF, a stable microporous Fe-MOF) was in situ modified with imidazole (IM) molecules to construct the soc-MOF-IM polycrystalline membrane. The exact location of the incorporated IM and the narrowed pore size are observed based on the determined crystal structure. The gas solubility, diffusivity and separation performance of the two membranes are evaluated. Compared to the soc-MOF membrane with a H2/CO2 selectivity of 6, the soc-MOF-IM polycrystalline membrane possesses a significantly enhanced H2/CO2 selectivity (48), which is mainly attributed to the triggered molecular sieving effect. Thanks to the facile introduction of functional molecules and precise adjustment of the pore environment, SBU modification can be a powerful strategy to improve the separation performance of MOF membranes.
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- 2020
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6. Three birds with one stone: Contemporaneously boosting passive, active and self-healing properties for long-term anticorrosion coatings
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Meng Cheng, Junhao Liu, Yuqi Liu, Hao Jiang, Chunling Li, Shuangqing Sun, and Songqing Hu
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General Chemical Engineering ,Environmental Chemistry ,General Chemistry ,Industrial and Manufacturing Engineering - Published
- 2023
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7. Smart polymer with rapid self-healing and early corrosion reporting capabilities: Design, performance and mechanism
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Hao Jiang, Zhikun Wang, Meng Cheng, Wuting Pang, Yizeng Mou, Fanjie Meng, Chunling Li, Shuangqing Sun, Songqing Hu, Zhigang Di, and Bingjie Lian
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General Chemical Engineering ,Environmental Chemistry ,General Chemistry ,Industrial and Manufacturing Engineering - Published
- 2023
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8. Anticorrosion mechanism of Cr-doped nickel-base alloy in Br/O environment: a DFT study
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Yunzhi Zhang, Junqiao Zhao, Lingran Xia, Li Jiyong, Shao Hongyun, Songqing Hu, and Dong Hao
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Materials science ,General Chemical Engineering ,Alloy ,Nickel base ,02 engineering and technology ,engineering.material ,01 natural sciences ,Condensed Matter::Materials Science ,Adsorption ,0103 physical sciences ,General Materials Science ,Physics::Chemical Physics ,Adsorption energy ,010304 chemical physics ,Cr doped ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Condensed Matter::Soft Condensed Matter ,Bond length ,Modeling and Simulation ,engineering ,Physical chemistry ,Condensed Matter::Strongly Correlated Electrons ,Density functional theory ,0210 nano-technology ,Mechanism (sociology) ,Information Systems - Abstract
Density functional theory was used to investigate the anticorrosion mechanism of Cr-doped nickel-base alloy in Br/O environment. The adsorption properties including adsorption energy, bond length a...
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- 2019
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9. Self-assembly of DCPD-loaded cross-linked micelle from triblock copolymers and its pH-responsive behavior: A dissipative particle dynamics study
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Zhikun Wang, Jianbang Gao, Pei Wang, Chunling Li, Songqing Hu, and Shuangqing Sun
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Materials science ,Applied Mathematics ,General Chemical Engineering ,Dissipative particle dynamics ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Methacrylate ,Micelle ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,020401 chemical engineering ,Chemical engineering ,chemistry ,Dicyclopentadiene ,PEG ratio ,Copolymer ,Self-assembly ,0204 chemical engineering ,0210 nano-technology ,Dispersion (chemistry) - Abstract
Dissipative particle dynamics (DPD) simulations were applied to investigate the solution self-assembly and pH-responsive behavior of hydrophobic DCPD (dicyclopentadiene)-loaded microcapsules from triblock copolymers poly (1,2-ethanediol, homopolymer-b-2-Diethylaminoethylmethacrylate-b-methyl methacrylate) (PEG- b -PDMAEMA- b -PMMA). Results indicate that micelles with longer hydrophilic PEG blocks and shorter hydrophobic PMMA blocks were in favor of encapsulating hydrophobic DCPD. Cross-linking at the core/shell interface generates a chemically bonded network structure in the micelle and leads to a significant decrease of their thermodynamic mobility (i.e., the increase of stability). Both non cross-linked and cross-linked micelles show a good pH-responsive behavior. In particular, cross-linked micelles still have the ability to carry DCPD due to the incomplete dispersion even completely protonation of PDMAEMA, which indicates that the cross-linked micelles could be expected to realize the slow release of encapsulated DCPD agent.
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- 2019
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10. Temperature and salt resistant CO2 responsive gas well foam: Experimental and molecular simulation study
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Chunling Li, Zhikun Wang, Wendong Wang, Huafeng Zhu, Shuangqing Sun, and Songqing Hu
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General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2022
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11. One-step Ethylene Purification from an Acetylene/Ethylene/Ethane Ternary Mixture by Cyclopentadiene Cobalt-Functionalized Metal-Organic Frameworks
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Mingyue Fu, Xiaoqing Lu, Zhikun Wang, Xiaokang Wang, Songqing Hu, Rongming Wang, Yue Li, Zixi Kang, Fangna Dai, Wenyue Guo, Weidong Fan, Yutong Wang, Lei Zhu, Chunlian Hao, and Daofeng Sun
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chemistry.chemical_classification ,Cyclopentadiene ,Ethylene ,Materials science ,010405 organic chemistry ,chemistry.chemical_element ,General Medicine ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Hydrocarbon ,chemistry ,Acetylene ,Chemical engineering ,Metal-organic framework ,Ternary operation ,Cobalt ,Kinetic diameter - Abstract
The separation of ethylene (C2 H4 ) from a mixture of ethane (C2 H6 ), ethylene (C2 H4 ), and acetylene (C2 H2 ) at normal temperature and pressure is a significant challenge. The sieving effect of pores is powerless due to the similar molecular size and kinetic diameter of these molecules. We report a new modification method based on a stable ftw topological Zr-MOF platform (MOF-525). Introduction of a cyclopentadiene cobalt functional group led to new ftw-type MOFs materials (UPC-612 and UPC-613), which increase the host-guest interaction and achieve efficient ethylene purification from the mixture of hydrocarbon gases. The high performance of UPC-612 and UPC-613 for C2 H2 /C2 H4 /C2 H6 separation has been verified by gas sorption isotherms, density functional theory (DFT), and experimentally determined breakthrough curves. This work provides a one-step separation of the ternary gas mixture and can further serve as a blueprint for the design and construction of function-oriented porous structures for such applications.
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- 2021
12. Potential and design of imine-linked two-dimensional covalent organic framework membranes for Ethane/Methane separation
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Hongbing Wang, Dingyun Wang, Yang Liu, Zhikun Wang, Chunling Li, Shuangqing Sun, Qiang Lyu, and Songqing Hu
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General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2022
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13. Effect of HPAM hydrolysis degree on catanionic mixtures of DTAB/HPAM: A coarse-grained molecular dynamic simulation
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Hongbing Wang, Shuangqing Sun, Songqing Hu, Chunling Li, Qianqian Zhu, and Pei Wang
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chemistry.chemical_classification ,General Computer Science ,Polyacrylamide ,Cationic polymerization ,General Physics and Astronomy ,02 engineering and technology ,General Chemistry ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Polyelectrolyte ,0104 chemical sciences ,Computational Mathematics ,chemistry.chemical_compound ,Molecular dynamics ,Hydrolysis ,chemistry ,Chemical engineering ,Pulmonary surfactant ,Mechanics of Materials ,General Materials Science ,Carboxylate ,0210 nano-technology - Abstract
Self-assembly of polymer and surfactant mixtures has attracted great interests because of its potential applications, ranging from tertiary oil recovery to drug delivery. However, the mechanism by which the hydrolysis degree of polymers promotes morphology transition is still experimentally challenging. In this study, self-assembly of the cationic surfactant dodecyltrimethylammonium bromide (DTAB) and anionic polyelectrolyte partially hydrolyzed polyacrylamide (HPAM) mixture was investigated by coarse-grained molecular dynamics (CG MD) simulation. In the polymer-surfactant mixtures, a sphere-to-rod transition of aggregates was obtained with the increasing concentration of DTAB. The increase of HPAM hydrolysis degree can promote the morphological transition from spherical into rod-like aggregates. Our simulation revealed that the flexibility of HPAM chain and the electrostatic attraction between DTAB headgroups ( N(CH3)3+) and HPAM carboxylate ions ( COO−) exerted a crucial role in promoting the morphological transition of aggregates. These simulation results brought to light the molecular-level information of sphere-to-rod transitions in polymer-surfactant aggregates. This work is expected to trigger further studies on morphology transition of polymer-surfactant mixtures.
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- 2018
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14. DFT study of imidazoles adsorption on the grain boundary of Cu (100) surface
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Hongbo Wang, Songqing Hu, Shenghui Chen, Yilei Hao, Meng Cheng, Chunling Li, and Shuangqing Sun
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Materials science ,Benzotriazole ,Hydrogen bond ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Crystallography ,Adsorption ,chemistry ,Chemisorption ,Imidazole ,Molecule ,General Materials Science ,Density functional theory ,Grain boundary ,0210 nano-technology - Abstract
Density functional theory was used to investigate the adsorption of imidazole (IMD), benzotriazole (BTAH) and 2-mercaptobenzoxazole (MBO) on the grain boundary (GB) of Cu (100) surface. Results show that molecules prefer to adsorb on the grain boundary with the larger distortion degree and more adsorption sites. The main interaction of molecules and grain boundary is chemisorption through C, N, S Cu bonds in both perpendicular and parallel modes. Hydrogen bonds and the lateral dipole-dipole interactions are also found. Based on the adsorption behaviour, the coverage effect and charge redistribution might be two possible inhibition mechanisms of inhibitor molecules.
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- 2018
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15. Molecular dynamics simulations of the aggregation behaviour of overlapped graphene sheets in linear aliphatic hydrocarbons
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Thomas E. Lacy, Songqing Hu, Steven R. Gwaltney, Chunling Li, Charles U. Pittman, Shuangqing Sun, and Shenghui Chen
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Materials science ,Graphene ,Dodecane ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,law.invention ,Hexane ,chemistry.chemical_compound ,Molecular dynamics ,chemistry ,Chemical physics ,law ,Modeling and Simulation ,General Materials Science ,0210 nano-technology ,Information Systems - Abstract
Molecular dynamics simulations were used to investigate the aggregation of two partially overlapped graphene sheets in hexane, dodecane and eicosane. When partially overlapped graphene shee...
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- 2018
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16. Fabrication and characterization of a TiO2/polysiloxane resin composite coating with full-thickness super-hydrophobicity
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Yangchao Sun, Shuangqing Sun, Songqing Hu, Meng Cheng, and Chunling Li
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Fabrication ,Materials science ,Scanning electron microscope ,Abrasion (mechanical) ,General Chemical Engineering ,Nanoparticle ,02 engineering and technology ,General Chemistry ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Contact angle ,Coating ,engineering ,Environmental Chemistry ,Thermal stability ,Fourier transform infrared spectroscopy ,Composite material ,0210 nano-technology - Abstract
We present a simple approach for the fabrication of a full-thickness super-hydrophobic composite coating consisted of modified TiO 2 nanoparticles and polysiloxane resin. Scanning electron microscope (SEM), fourier transform infrared spectrometer (FTIR), contact angle meter and a simple self-made device were employed to characterize the surface morphologies, chemical compositions, contact angle and sliding angle of the modified TiO 2 nanoparticles and composite coating, respectively. Results show that for both the modified TiO 2 nanoparticles and the as-prepared composite coating the contact angle and sliding angle of is up to 152° and 0°, respectively. In addition, due to the coating design of full-thickness super-hydrophobicity, the composite coating also exhibited good thermal stability, abrasion resistance and corrosion resistance in the thermo-gravimetric analysis (TGA) experiment, abrasion test and immersion test, respectively.
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- 2018
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17. Nanocatalyst-mediated oxygen depletion in epoxy coating for active corrosion protection
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Zhikun Wang, Chunling Li, Songqing Hu, Meng Cheng, Shuangqing Sun, and Hao Jiang
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Materials science ,General Chemical Engineering ,Dispersity ,chemistry.chemical_element ,General Chemistry ,Epoxy ,engineering.material ,Oxygen ,Industrial and Manufacturing Engineering ,Catalysis ,Corrosion ,Coating ,chemistry ,Chemical engineering ,visual_art ,engineering ,visual_art.visual_art_medium ,Environmental Chemistry ,Pyrolysis ,Carbon - Abstract
Smart coatings depending on external nanocontainers are often complex and expensive, which can only inhibit local corrosion depending on the microenvironment change after corrosion. In this work, nanocatalytic anticorrosion based on silica coated nitrogen enriched hollow carbon spheres (NHCs@mSiO2) is developed to achieve the prolongation of coating lifetime and long-term protection of metals. Obtained NHCs@mSiO2 by confined space pyrolysis strategy shows a double-shelled hollow structure with interior N-doped carbon shell and exterior silica shell. Moreover, the NHCs@mSiO2 spheres possess favorable catalytic ability for oxygen thanks to the incorporation of nitrogen. When blended into epoxy coatings, amphiphilic NHCs@mSiO2 spheres distribute uniformly and occupy the pores or cracks in composite coatings. The diffused oxygen through coating micropores are preferentially adsorbed by NHCs@mSiO2 and directly reduced to water through four-electron pathways. Therefore, the corrosion is greatly avoided due to the depletion of oxygen. The introduction of nano-catalyst with excellent dispersity and oxygen reduction ability will pave the way toward the development of new smart coatings with active corrosion resistance.
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- 2021
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18. Two-dimensional imine covalent organic frameworks for methane and ethane separation: A GCMC simulation study
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Chunling Li, Hongbing Wang, Qiang Lyu, Shuangqing Sun, Songqing Hu, Zhikun Wang, Yang Liu, and Yanyan Liu
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Materials science ,Imine ,General Chemistry ,Condensed Matter Physics ,Methane ,chemistry.chemical_compound ,Tetragonal crystal system ,Monomer ,Adsorption ,chemistry ,Chemical engineering ,Mechanics of Materials ,General Materials Science ,Porous medium ,Porosity ,Selectivity - Abstract
Separation of methane and ethane using porous materials is a challenge. Size exclusion will reduce the working capacity and increase the difficulty of material fabrication. Covalent organic frameworks (COFs) are hopeful due to the adsorption selectivity of C2H6/CH4 and other advantages. In this paper, we used the grand canonical Monte Carlo (GCMC) simulations to study the adsorption behavior of 1171 theoretical two-dimensional (2D) imine COFs, focusing on the effects of monomer structure and composition on the and C2H6/CH4 separation performance. 11 structures with excellent performance were screened according to C2H6 working capacity and the C2H6/CH4 selectivity. COFs with trigonal nodes were found to have better performance than that with tetragonal nodes. It is supposed that the shape, size, and spatial ductility of the nodes have important effects on structural parameters such as largest free sphere diameter (LCD), surface area, and void fraction. In addition, the nitrogen content of these COFs also has a significant effect on the separation performance of CH4 and C2H6, which is mainly related to the way of nitrogen introduction. We hope that the results of this study can provide guidance for the monomer selection and structural design of the separation materials for CH4 and C2H6.
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- 2021
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19. DFT study on the adsorption of deprotonated benzotriazole on the defective copper surfaces
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Shuangqing Sun, Zhikun Wang, Songqing Hu, Yunying Jiang, Fengting Li, Chunling Li, and Shougang Chen
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Materials science ,Benzotriazole ,020209 energy ,General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Copper ,Metal ,Corrosion inhibitor ,chemistry.chemical_compound ,Adsorption ,chemistry ,Impurity ,visual_art ,Vacancy defect ,0202 electrical engineering, electronic engineering, information engineering ,visual_art.visual_art_medium ,Physical chemistry ,General Materials Science ,Density functional theory ,0210 nano-technology - Abstract
Density functional theory calculation was conducted to investigate the adsorption behavior and mechanism of benzotriazole (BTA) on the copper surface with the defects of vacancy, impurity, and grain boundary (GB). On the Cu (111) surface with vacancies, BTA tends to obliquely, rather than vertically, adsorb on the copper surface. The surface doped with Zn and O has stronger adsorption activity for negatively charged particles compared with the surface doped with Ni and S. For impurity and GB surface, the adsorption energy and transferred charge show that the oblique and horizontal adsorption configurations are more stable than the vertical adsorption of BTA. Our findings provide profound explanation for corrosion inhibitor protection of defective metal surface.
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- 2021
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20. Molecular dynamics simulations of aggregation behavior of sodium dodecyl sulfate on SiO2 and CaCO3 surfaces
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Wang Xiumin, Shuangqing Sun, Gang Wu, Congtai Yuan, Chunling Li, Songqing Hu, and Qianqian Zhu
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Thesaurus (information retrieval) ,Chemical substance ,Solid surface ,Kinetics ,Molecular simulation ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Search engine ,Molecular dynamics ,chemistry ,Chemical engineering ,Materials Chemistry ,Sodium dodecyl sulfate ,0210 nano-technology - Published
- 2017
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21. Fabrication of a Hydrogen-Bonded Organic Framework Membrane through Solution Processing for Pressure-Regulated Gas Separation
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Zhanning Liu, Yanxue Shang, Zhikun Wang, Songqing Hu, Weidong Fan, Yang Feng, Daofeng Sun, Shou Feng, Rongming Wang, Zixi Kang, Hailing Guo, Jianzhuang Jiang, Lili Fan, and Guodong Kong
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Materials science ,Fabrication ,Hydrogen ,010405 organic chemistry ,Hydrogen bond ,chemistry.chemical_element ,General Medicine ,General Chemistry ,Microporous material ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Solvent vapor ,Membrane ,Chemical engineering ,chemistry ,Gas separation ,Porosity - Abstract
Ordered and flexible porous frameworks with solution processability are highly desirable to fabricate continuous and large-scale membranes for the efficient gas separation. Herein, the first microporous hydrogen-bonded organic framework (HOF) membrane has been fabricated by an optimized solution-processing technique. The framework exhibits the superior stability because of the abundant hydrogen bonds and strong π-π interactions. Thanks to the flexible HOF structure, the membrane possesses the unprecedented pressure-responsive H2 /N2 separation performance. Furthermore, the scratched membrane can be healed by the treatment of solvent vapor, achieving the recovery of separation performance.
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- 2019
22. Theoretical Prediction of Mechanical Strength and Desalination Performance of One-Atom-Thick Hydrocarbon Polymer in Pressure-Driven Separation
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Fei Shan, Qiang Lyu, Songqing Hu, Shuangqing Sun, and Chunling Li
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chemistry.chemical_classification ,Work (thermodynamics) ,Materials science ,Polymers and Plastics ,Continuum mechanics ,General Chemistry ,Polymer ,mechanical strength ,Desalination ,Article ,molecular simulation ,law.invention ,membrane-based separation ,lcsh:QD241-441 ,Hydrocarbon ,Membrane ,lcsh:Organic chemistry ,chemistry ,law ,water desalination ,two-dimensional hydrocarbon polymer ,Composite material ,Reverse osmosis ,Filtration - Abstract
One-atom-thick materials hold promise for the future of membrane-based gas purification and water filtration applications. However, there are a few investigations on the mechanical properties of these materials under pressure-driven condition. Here, by employing molecular simulation techniques and continuum mechanics simulation, we investigate the mechanical strength of two-dimensional hydrocarbon polymers containing sub-nanometer pores with various topologies. We demonstrate that the mechanical strengths of the membranes are correlated with their pore sizes and geometries. In addition, when the pore size of substrates is controlled within a reasonable range, all of the membrane candidates can withstand the practical hydraulic pressure of few megapascal. The studied materials also exhibit better seawater desalination performance as compared to the traditional polymeric reverse osmosis membrane. This work presents a new route to design new separation membrane, and also propose a simulation method to evaluate the mechanical strength and desalination performance.
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- 2019
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23. Effect of Carbon Nanotube Addition on the Interfacial Adhesion between Graphene and Epoxy: A Molecular Dynamics Simulation
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Shuangqing Sun, Shenghui Chen, Fei Shan, Weng Xuanzhou, and Songqing Hu
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Materials science ,Polymers and Plastics ,Composite number ,Carbon nanotube ,composites ,Article ,law.invention ,lcsh:QD241-441 ,Molecular dynamics ,Matrix (mathematics) ,lcsh:Organic chemistry ,law ,pullout ,Composite material ,carbon nanotube ,chemistry.chemical_classification ,Graphene ,graphene ,General Chemistry ,Polymer ,Interaction energy ,Epoxy ,molecular dynamics simulation ,chemistry ,visual_art ,visual_art.visual_art_medium - Abstract
The pullout process of graphene from an epoxy/graphene composite filled with a carbon nanotube (CNT) was simulated by molecular dynamics simulations. The interaction energy and the interfacial adhesion energy were calculated to analyze the effect of CNT addition on the interfacial adhesion between the graphene and the epoxy matrix, with varying CNT radii, distances between the CNT and the graphene sheet, CNT axial directions, and the number of CNT walls. Generally, the addition of a CNT strengthens the interfacial adhesion between the graphene and the polymer matrix. Firstly, a larger CNT radius induces a stronger interfacial adhesion of graphene with the matrix. Secondly, when the CNT is farther away from the graphene sheet, the interfacial adhesion of graphene with the matrix becomes weaker. Thirdly, the CNT axial direction has little effect on the interfacial adhesion of graphene in the equilibrium structure. However, it plays an important role in the graphene pullout process. Finally, compared with a single-walled CNT, the interfacial adhesion between graphene and the matrix is stronger when a double-walled CNT is added to the matrix.
- Published
- 2019
24. Back Cover: One‐step Ethylene Purification from an Acetylene/Ethylene/Ethane Ternary Mixture by Cyclopentadiene Cobalt‐Functionalized Metal–Organic Frameworks (Angew. Chem. Int. Ed. 20/2021)
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Daofeng Sun, Songqing Hu, Lei Zhu, Xiaoqing Lu, Yue Li, Weidong Fan, Wenyue Guo, Xiaokang Wang, Zhikun Wang, Yutong Wang, Fangna Dai, Rongming Wang, Zixi Kang, Mingyue Fu, and Chunlian Hao
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Ethylene ,Cyclopentadiene ,chemistry.chemical_element ,One-Step ,General Chemistry ,Catalysis ,chemistry.chemical_compound ,chemistry ,Acetylene ,Polymer chemistry ,Metal-organic framework ,Cover (algebra) ,Ternary operation ,Cobalt - Published
- 2021
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25. Study on the influence of the external conditions and internal components on foam performance in gas recovery
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Qi Yang, Shuangqing Sun, Hongbing Wang, Songyan Li, Songqing Hu, Ji Liu, and Yan Wang
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Alkane ,chemistry.chemical_classification ,Materials science ,Applied Mathematics ,General Chemical Engineering ,Fatty alcohol ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Instability ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,Molecular dynamics ,Temperature and pressure ,020401 chemical engineering ,chemistry ,Phase (matter) ,Molecule ,Foam film ,0204 chemical engineering ,Composite material ,0210 nano-technology - Abstract
In the lifting process of drainage gas recovery, external conditions and internal components of the foam are complex. We used molecular dynamics simulation to construct a series of fatty alcohol polyoxyethylene ether sulfate (AES) foam models that could represent various foams in different lifting stages from well to ground. The effect of temperature and pressure on foam stability was investigated. We found that there are two main reasons for foam instability in the first-half stage of the lifting process. Firstly, high temperature aggravated the molecule movement; some CH4 molecules entered the foam film and formed a molecular transport channel. Secondly, the interaction between the CH4 phase and condensate oil leads to some alkane molecules entering the gas–liquid interface. The calculation results and theoretical analysis will help to deepen the understanding of the performance of oily foams under harsh conditions.
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- 2021
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26. Synthesis of magnetic Fe3O4@PS-ANTA-M2+ (M = Ni, Co, Cu and Zn) nanospheres for specific isolation of histidine-tagged proteins
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Xilong Du, Yi Shen, Yong Cao, Zuoqi Gai, Guo Liu, Songqing Hu, Moyan Ge, Renshui Fan, and Jiali Zhang
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Thermogravimetric analysis ,Chemistry ,General Chemical Engineering ,Metal ions in aqueous solution ,Isothermal titration calorimetry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Adsorption ,Protein purification ,Environmental Chemistry ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Selectivity ,Hydrate ,Nuclear chemistry - Abstract
Developing high-performance materials for efficient isolation of proteins is of great importance. Herein, the authors synthesized a series of magnetic Fe3O4@PS-ANTA-M2+ (M = Ni, Co, Cu and Zn) nanospheres, consisting of fine Fe3O4 nanoparticles encapsulated by functionalized polystyrene shell, where metal ions were complexed by Nα, Nα-Bis(carboxymethyl)-L-lysine hydrate for selectively immobilizing histidine (His)-tagged proteins. The structures of the Fe3O4@PS-ANTA-M2+ were studied by field scanning electron microscopy, transmission microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and vibrating sample magnetometer. The adsorption performance of the Fe3O4@PS-ANTA-M2+ was studied using bovine hemoglobin as a model protein. The thermodynamics of the binding process was studied by isothermal titration calorimetry tests. The resulting Fe3O4@PS-ANTA-Cu2+, Fe3O4@PS-ANTA-Ni2+, Fe3O4@PS-ANTA-Co2+ and Fe3O4@PS-ANTA-Zn2+ possessed adsorption capacities of 21200, 8080, 6640 and 5360 mg g−1, respectively, rendering them as the best adsorbents for protein purification. The adsorption isotherm was better fitted by Langmuir equation. To verify the selectivity, the Fe3O4@PS-ANTA-M2+ was practically employed to isolate His-tagged proteins from cell lysate. The results indicated that the samples showed outstanding adsorption capacity, selectivity and stability, and facile regeneration and separation, outperforming a commercial NTA-Ni column. These findings suggested that the Fe3O4@PS-ANTA-M2+ showed promising applications for specifically isolating proteins from complex biological systems.
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- 2021
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27. Adsorption behavior of carbon dioxide and methane in bituminous coal: A molecular simulation study
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Songqing Hu, Dou Wu, Bin Fan, Hongxing Yao, Jing You, Li Tian, and Chao Zhang
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Bituminous coal ,Environmental Engineering ,Petroleum engineering ,General Chemical Engineering ,geology.rock_type ,Heteroatom ,geology ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Mole fraction ,01 natural sciences ,Biochemistry ,Methane ,chemistry.chemical_compound ,Molecular dynamics ,Adsorption ,chemistry ,Chemical engineering ,Enhanced coal bed methane recovery ,Carbon dioxide ,0210 nano-technology ,0105 earth and related environmental sciences - Abstract
The adsorption behavior of CO2, CH4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic (MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo (GCMC) simulations were then carried out to investigate the single and binary component adsorption of CO2 and CH4 with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO2 adsorption is greater than that of CH4 adsorption. CO2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH4, which can account for the larger adsorption capacity of CO2 in the bituminous coal model. In the case of binary adsorption of CO2 and CH4 mixtures, CO2 exhibits the preferential adsorption compared with CH4 under the studied conditions. The adsorption selectivity of CO2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO2 decreases gradually with the increase of the bulk CO2 mole fraction and the depth of CO2 injection site.
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- 2016
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28. Inhibitor-self-gated stimuli-responsive anticorrosion system based on π-π stacking
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Qiang Lyu, Songqing Hu, Meng Cheng, Chunling Li, Shuangqing Sun, Zhikun Wang, Beiluo Shan, and Xiyu Zhao
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Materials science ,Fabrication ,Stimuli responsive ,General Chemical Engineering ,Alloy ,Stacking ,Nanocontainer ,02 engineering and technology ,General Chemistry ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Corrosion ,Mesoporous organosilica ,Chemical engineering ,Copper alloy ,engineering ,Environmental Chemistry ,0210 nano-technology - Abstract
Most of existing nanocontainers suffer from tedious, complicated and unsustainable assembly process which restricts their application in corrosion protection as smart inhibitor carriers. In this study, we adopted the framework-hybridization approach to prepare a smart anticorrosion system (MBT@Ph-HPMO), with MBT inhibitor as cargo and phenylene-bridged hollow periodic mesoporous organosilica (Ph-HPMO) as nanocontainer. Results reveal that the π-π stacking between MBT and framework of Ph-HPMO serves as nature valve, which is supplemented by the molecular dynamic simulation. The encapsulated inhibitor was loaded into Ph-HPMO at neutral pH, demonstrating fast release in acidic environment. On-demand release of inhibitors from MBT@Ph-HPMO contributed to achieving in situ active corrosion protection. Anticorrosion performance of MBT@Ph-HPMO for copper alloy was evaluated in 3.5 wt% NaCl solution for a period of 30 days. The alloy exhibited the slightest corrosion damage in the corrosion medium with the addition of 0.24 wt% MBT@Ph-HPMO. This facile and versatile strategy will have broad applications in new class of nanocontainers fabrication and open up a new prospect for active corrosion protection.
- Published
- 2020
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29. Exploiting interior surface functionalization in reverse osmosis desalination membranes to mitigate permeability–selectivity trade-off: Molecular simulations of nanotube-based membranes
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Dun-Yen Kang, Li-Chiang Lin, Qiang Lyu, and Songqing Hu
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Nanotube ,Materials science ,Mechanical Engineering ,General Chemical Engineering ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Permeation ,021001 nanoscience & nanotechnology ,Desalination ,Membrane ,020401 chemical engineering ,Surface modification ,General Materials Science ,0204 chemical engineering ,0210 nano-technology ,Selectivity ,Porous medium ,Reverse osmosis ,Water Science and Technology - Abstract
Increasing demand for affordable desalinating water has stimulated the vigorous development of reverse osmosis (RO) membranes. To date, the performance of polymeric membranes is limited by the permeability–selectivity trade-off: more permeable membranes lead to a less ideal selectivity and vice versa. Significant efforts have been made to identify new classes of ultra-permeable nanoporous membranes, but such trade-off can still be commonly observed. In this study, we identify the key role of the surface uniformity and chemistry of permeation channels inside nanoporous membranes in mitigating the trade-off. By using highly tunable aluminosilicate nanotubes (AlSiNTs) as a model system, this study demonstrates that, by properly designing the interior surface of AlSiNTs, the materials can offer not only higher water permeability but also a better ability to reject salts. Detailed investigations on the capacity, dynamics, energetics, and distribution of water as well as the free energy landscapes for water molecules and ions are also carried out to understand the permeation mechanisms of species at an atomic level. The outcomes obtained herein can provide guidelines for the rational design of nanotube-based membranes, or porous materials in general, to achieve more efficient and effective desalination processes.
- Published
- 2020
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30. Inside Cover: Fabrication of a Hydrogen‐Bonded Organic Framework Membrane through Solution Processing for Pressure‐Regulated Gas Separation (Angew. Chem. Int. Ed. 10/2020)
- Author
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Songqing Hu, Daofeng Sun, Rongming Wang, Shou Feng, Zhanning Liu, Lili Fan, Yanxue Shang, Hailing Guo, Zhikun Wang, Zixi Kang, Weidong Fan, Yang Feng, Guodong Kong, and Jianzhuang Jiang
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Membrane ,Materials science ,Fabrication ,Chemical engineering ,Hydrogen ,chemistry ,INT ,chemistry.chemical_element ,Cover (algebra) ,General Chemistry ,Gas separation ,Catalysis - Published
- 2020
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31. Effects of coverage and solvent on H2S adsorption on the Cu(100) surface: A DFT study
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Bingjie Lian, Songqing Hu, Shenghui Chen, Shuangqing Sun, and Yunfei Ma
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Solvent ,Surface (mathematics) ,Adsorption ,Computational chemistry ,Chemistry ,Materials Chemistry ,Density functional theory ,Surfaces and Interfaces ,General Chemistry ,Solvent effects ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2015
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32. Glass transition investigations on highly crosslinked epoxy resins by molecular dynamics simulations
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Shenghui Chen, Zhikun Wang, Chunling Li, Qiang Lv, Shuangqing Sun, and Songqing Hu
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Materials science ,Diglycidyl ether ,Internal energy ,General Chemical Engineering ,Diffusion ,Thermosetting polymer ,General Chemistry ,Epoxy ,Condensed Matter Physics ,Molecular dynamics ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,Modeling and Simulation ,visual_art ,Polymer chemistry ,visual_art.visual_art_medium ,General Materials Science ,Composite material ,Glass transition ,Information Systems - Abstract
Molecular dynamics simulations at the atomistic level were performed to investigate the glass transition of a highly crosslinked thermoset epoxy resin system composed of diglycidyl ether bisphenol A and isophorone diamine. The crosslinked model was first constructed using a cyclic dynamic method, and extended by investigating the effect of conversion degree on the static properties of local structure, internal energy and volume shrinkage. Based on this model, a systematic investigation on volume, energy and dynamic properties against temperature was made, which determined the glass transition temperature (Tg). The Tgs obtained from various volumetric and energy properties agree well with the differential scanning calorimetry experimental data available, yet a dynamic Tg obtained from the diffusion coefficient is relatively higher. Moreover, the investigation on epoxy segmental dynamics confirmed that the glass transition of the highly crosslinked epoxy resin has a strong dependence on the backbone bond to...
- Published
- 2015
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33. Controllable multicompartment morphologies from cooperative self-assembly of copolymer-copolymer blends
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Songqing Hu, Shuangqing Sun, Zhikun Wang, Chunling Li, and Roland Faller
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chemistry.chemical_classification ,Materials science ,Nanostructure ,Chemical Physics ,Shell (structure) ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Micelle ,Surface energy ,0104 chemical sciences ,Engineering ,chemistry ,Chemical engineering ,Chemical Sciences ,Physical Sciences ,Copolymer ,Self-assembly ,0210 nano-technology ,Ternary operation - Abstract
Multicompartment nanostructures, such as microcapsules with clearly separated shell and core, are not easily accessible by conventional block copolymer self-assembly. We assess a versatile computational strategy through cooperative assembly of diblock copolymer blends to generate spherical and cylindrical compartmentalized micelles with intricate structures and morphologies. The co-assembly strategy combines the advantages of polymer blending and incompatibility-induced phase separation. Following this strategy, various nanoassemblies of pure AB, binary AB/AC and ternary AB/AC/AD systems such as compartmentalized micelles with sponge-like, Janus, capsule-like and onion-like morphologies can be obtained. The formation and structural adjustment of microcapsule micelles, in which the shell or core can be occupied by either pure or mixed diblock copolymers, were explored. The mechanism involving the separation of shell and core copolymers is attributed to the stretching force differences of copolymers which drive the arrangement of different copolymers in a pathway to minimize the total interfacial energy. Moreover, by adjusting block interactions, an efficient approach is exhibited for regulating the shell or core composition and morphology in microcapsule micelles, such as the transition from the "pure shell/mixed core" morphology to the "mixed shell/pure core" morphology in the AB/AC/AD micelle. This mesoscale simulation study identifies the key factors governing co-assembly of diblock copolymer blends and provides bottom-up insights towards the design and optimization of new multicompartment micelles.
- Published
- 2017
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34. Molecular dynamics simulations of the graphene sheet aggregation in dodecane
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Shuangqing Sun, Chunling Li, Charles U. Pittman, Steven R. Gwaltney, Thomas E. Lacy, Songqing Hu, and Shenghui Chen
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Materials science ,Graphene ,Dodecane ,Aggregation rate ,Bioengineering ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Molecular dynamics ,chemistry ,law ,Chemical physics ,Modeling and Simulation ,Molecule ,General Materials Science ,0210 nano-technology ,Layer (electronics) - Abstract
Molecular dynamics simulations are used to investigate the aggregation and behavior of two parallel graphene sheets (22.0–64.0 A in length) in dodecane. The dodecane layer formed on the graphene surface leads to an energy barrier which slows the rate of the graphene aggregation process when the two sheets are totally separated by dodecane molecules. The graphene sheets aggregate in dodecane only when portions of one graphene sheet are in contact with another sheet. The aggregation rate depends on the combined structures of the two graphene sheets. The aggregation rate for two parallel graphene sheets in half contact with one another is constant since the relative sheet geometry and spacing are nearly constant in the transition region between sheets where dodecane molecules are being displaced during aggregation. The aggregation rate for partially overlapped graphene sheets becomes progressively slower as aggregation continues since the area not overlapped decreases as the aggregation proceeds.
- Published
- 2017
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35. Exfoliation Corrosion of Extruded AA2024-T4 in the Industrial and Coastal-Industrial Environments
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Shuangqing Sun, Shenghui Chen, Yunfei Ma, Qifei Zheng, and Songqing Hu
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Materials science ,Exfoliation corrosion ,Critical relative humidity ,General Chemical Engineering ,Metallurgy ,Alloy ,engineering ,General Materials Science ,General Chemistry ,engineering.material ,Corrosion - Abstract
Exfoliation of extruded AA2024-T4 (UNS A92024) in the industrial and coastal-industrial environments was investigated by the field test and laboratory-accelerated test. Results show that the exfoliation corrosion was influenced by the alloy structure and the type of the atmospheric environment, especially the concentration of SO42− in the environment. In the field test, AA2024-T4 suffered slighter exfoliation in both environments than that in the coastal environments. The side wall with a thinner coarse-grain structure of extruded AA2024-T4 suffered more severe exfoliation than the bottom with a thicker coarse-grain structure after a 20-year exposure. Energy-dispersive spectroscopy (EDS) results show that the corrosion products of extruded AA2024-T4 exposed in both environments contained a small amount of S in addition to a large amount of Al and O. In the laboratory-accelerated test, both the critical relative humidity (RH) and induction period for exfoliation in the simulated coastal-industrial environm...
- Published
- 2014
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36. CO2/N2 switchable aqueous foam stabilized by SDS/C12A surfactants: Experimental and molecular simulation studies
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Hongbing Wang, Shengxiang Feng, Songqing Hu, Chunling Li, Xiqiang Zhang, Yan Wang, Jianhui Luo, and Shuangqing Sun
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Materials science ,Aqueous solution ,Applied Mathematics ,General Chemical Engineering ,Molecular simulation ,Protonation ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,Pulmonary surfactant ,Chemical engineering ,Phase (matter) ,Molecule ,Amine gas treating ,0204 chemical engineering ,Sodium dodecyl sulfate ,0210 nano-technology - Abstract
A novel CO2/N2 switchable aqueous foam was developed using a CO2-responsive surfactant N,N-dimethyl-N-dodecyl amine (C12A) and a conventional surfactant sodium dodecyl sulfate (SDS). The performance and mechanism of this switchable foam were studied by both experiment and molecular simulation methods. Experimental results demonstrate that the foam stabilized by SDS/C12A surfactants has better stability and water carrying capacity than single C12A foam. The foam could be rapidly switched between stable and unstable states at ambient temperature with CO2 or N2 as the triggers. Simulation results shows that when CO2 was introduced, most of SDS and C12A molecules aggregated in the water phase, instead of adsorbing at the air-water interface to stabilize the foam films. The strong electrostatic attraction between protonated C12A and SDS molecules could account for the aggregation. Due to the presence of limited surfactants located at the air-water interface after introducing CO2, the foam bursts quickly.
- Published
- 2019
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37. Intergranular-stress corrosion cracking mechanism of brass in H2S environment: A DFT study
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Songqing Hu, Hongbo Wang, Yilei Hao, Chunling Li, Shuangqing Sun, and Le Zhang
- Subjects
Materials science ,General Computer Science ,General Physics and Astronomy ,02 engineering and technology ,General Chemistry ,Intergranular corrosion ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Corrosion ,Brass ,Computational Mathematics ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Grain boundary ,Composite material ,Stress corrosion cracking ,0210 nano-technology ,Tensile testing ,Metallic bonding - Abstract
Density functional theory and first-principles computational tensile test were used to investigate the intergranular-stress corrosion mechanism of brass in H2S environment. Results show that the complicated structure of grain boundary makes H2S and its decomposed corrosive ions adsorb on the surface more easily. The segregation of Zn atoms is conducive to the decomposition of H2S and the permeation of H atom. H permeation in the grain boundary can weaken the strength of metallic bond. GB structure, Zn segregation and H permeation all facilitate the intergranular-stress corrosion process of brass in H2S environment under the action of external stress.
- Published
- 2019
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38. Emulsified oil phase induced internal instability of ionic and nonionic foams revealed by coarse-grained molecular dynamics simulation
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Xiqiang Zhang, Songqing Hu, Zhikun Wang, Shuangqing Sun, Pei Wang, Jianhui Luo, Hongbing Wang, and Chunling Li
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Materials science ,General Computer Science ,Pentaethylene glycol monododecyl ether ,General Physics and Astronomy ,Ionic bonding ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrostatics ,01 natural sciences ,Instability ,0104 chemical sciences ,Computational Mathematics ,chemistry.chemical_compound ,Molecular dynamics ,chemistry ,Chemical engineering ,Mechanics of Materials ,Phase (matter) ,Molecule ,General Materials Science ,Sodium dodecyl sulfate ,0210 nano-technology - Abstract
Oil phase has strong hydrophobicity and weak interface tension in the foam system, which will destroy the internal structure of foam and reduce the intrinsic stability of the foam film. Coarse-grained molecular simulation techniques were employed to investigate the effect of oil phases on the structural instabilities of two typical foam systems, i.e., ionic sodium dodecyl sulfate (SDS) and nonionic pentaethylene glycol monododecyl ether (C 12 E 5 ). In both systems, the pseudo-emulsion film ruptures at a critical thickness, subsequently the oil phase enters the air-water interface subsequently. Instability mechanisms are obtained by analyzing dynamic processes of the foam systems. For the SDS foam system, an oil-bridge is formed in the foam film, which is attributed to the electrostatic repulsion between the SDS at the oil-water interface and that at the air-water interface, as well as the discontinuous distribution of SDS at the air-water interface caused by the structural reversal of SDS molecules. However, for the C 12 E 5 foam system, oil phase spreads at the air-water interfaces, which is caused by the continuous distribution of the C 12 E 5 molecules at the air-water interface and the attractive interaction between the neutral C 12 E 5 molecules at the air-water interface and that at the oil-water interface. The outcomes of this work shed light on the destructive mechanism of foam films induced by oil phase and provide guidelines for the design of novel oil-resistant foam system.
- Published
- 2019
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39. Behavior of protruding lateral plane graphene sheets in liquid dodecane: molecular dynamics simulations
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Songqing Hu, Thomas E. Lacy, Shenghui Chen, Steven R. Gwaltney, Chunling Li, Shuangqing Sun, and Charles U. Pittman
- Subjects
Materials science ,Dodecane ,Bioengineering ,Nanotechnology ,02 engineering and technology ,Edge (geometry) ,010402 general chemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Molecular dynamics ,Stack (abstract data type) ,law ,Molecule ,General Materials Science ,Plane (geometry) ,Graphene ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,chemistry ,Chemical physics ,Modeling and Simulation ,0210 nano-technology - Abstract
Molecular dynamics simulations are used to investigate the behavior of two parallel graphene sheets fixed on one edge (lateral plane) in liquid dodecane. The interactions of these sheets and dodecane molecules are studied with different starting inter-sheet distances. The structure of the dodecane solvent is also analyzed. The results show that when the distance between the two graphene sheets is short (less than 6.8 A), the sheets will expel the dodecane molecules between them and stack together. However, when the distance between two sheets is large (greater than 10.2 A), the two sheets do not come together, and the dodecane molecules will form ordered layers in the interlayer spacing. The equilibrium distance between the graphene sheets can only take on specific discrete values (3.4, 7.8, and 12.1 A), because only an integer number of dodecane layers forms between the two sheets. Once the graphene sheets are in contact, they remain in contact; the sheets do not separate to allow dodecane into the interlayer spacing.
- Published
- 2016
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40. Density functional theory study of imidazole, benzimidazole and 2-mercaptobenzimidazole adsorption onto clean Cu(111) surface
- Author
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Songqing Hu, Youguo Yan, Shenghui Chen, Yufeng Geng, Shuangqing Sun, and Li Tian
- Subjects
Benzimidazole ,Hydrogen bond ,General Chemical Engineering ,Inorganic chemistry ,General Chemistry ,chemistry.chemical_compound ,Crystallography ,Adsorption ,chemistry ,Chemisorption ,Imidazole ,Molecule ,General Materials Science ,Density functional theory ,Dehydrogenation - Abstract
Density functional theory was used to investigate the adsorption of three corrosion inhibitors on the Cu(1 1 1) surface in both neutral and dehydrogenated forms, including imidazole, benzimidazole and 2-mercaptobenzimidazole. Results show that three neutral molecules can weakly chemisorb perpendicularly on the surface through N Cu or S Cu bond as well as the X H⋯Metal hydrogen bond (X = C or S). Neutral benzimidazole and 2-mercaptobenzimidazole can physisorb almost parallel to the surface. The dehydrogenated molecules can strongly chemisorb on the surface with both perpendicular and tilt adsorption configurations, and their chemisorption strength order is consistent with the experimental results of inhibiting efficiency.
- Published
- 2012
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41. Growth analysis of novel ZnO nanotetrapods with tubular legs from aspect of reagent’s vapor pressure and growth temperature
- Author
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Lixia Zhou, Shuangqing Sun, Yuhua Zhen, Jun Zhang, Songqing Hu, and Youguo Yan
- Subjects
Nanostructure ,Materials science ,Chemical engineering ,Vapor pressure ,Reagent ,General Materials Science ,Nanotechnology ,General Chemistry ,Growth model - Abstract
In this article, novel ZnO nanotetrapods with tubular legs was successfully synthesized using mixed powder of Zn, ZnO, and carbon as source. The growth process was analyzed at large, and a two-step growth model, viz. initial deficient-oxidation and latter second-volatilization, was proposed to explain the formation of tubular leg of ZnO nanotetrapod. In the growth model, the high Zn vapor pressure and high growth temperature were considered as two crucial factors determining the growth behavior. Zn-rich ZnO nanotetrapod formed under high Zn vapor pressure at the initial stage. These redundant Zn clusters coexisted in ZnO lattice as interstitial Zn. The following second-volatilization of interstitial Zn under high growth temperature led to formation of tubular leg. Four other experiments were designed to analyze the growth behavior under high and low Zn vapor pressure and growth temperature, respectively, and these experimental results further confirmed the validity of our growth model. Our experiment proposed a feasible synthesis route to prepare hollow nanostructures controlled by the vapor pressure and growth temperature. Furthermore, these novel ZnO nanotetrapods might have potential application as building blocks for functional nanodevices.
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- 2012
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42. Exfoliation corrosion of extruded 2024-T4 in the coastal environments in China
- Author
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Songqing Hu, Shuangqing Sun, Defu Li, Junguo Wen, and Qifei Zheng
- Subjects
Exfoliation corrosion ,Materials science ,Atmospheric corrosion ,Test site ,General Chemical Engineering ,Metallurgy ,General Materials Science ,Relative humidity ,General Chemistry ,Exfoliation joint ,Corrosion - Abstract
Exfoliation behavior of extruded 2024-T4 in four coastal environments was investigated by the field testing and laboratory-accelerated test. At the Wanning, Qionghai and Qingdao test sites, exfoliation appeared on 2024-T4 after 6, 10 and 20 years exposure, respectively. At the Guangzhou test site, 2024-T4 did not suffer exfoliation after 20 years exposure. In the laboratory-accelerated test, the effects of relative humidity, temperature and Cl − amount on exfoliation were studied. Exfoliation could not occur on extruded 2024-T4 when RH was below 75%. Above this RH, the higher the temperature or the Cl − amount was, the more serious exfoliation the specimen suffered.
- Published
- 2011
- Full Text
- View/download PDF
43. Molecular dynamics simulation of corrosive particle diffusion in benzimidazole inhibitor films
- Author
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Weizhao Yu, Yang Ti, Youguo Yan, Jun Zhang, Lijun Yu, Guimin Qiao, and Songqing Hu
- Subjects
Benzimidazole ,Materials science ,General Chemical Engineering ,Diffusion ,Metallurgy ,General Chemistry ,Microstructure ,Corrosion ,chemistry.chemical_compound ,Corrosion inhibitor ,Molecular dynamics ,chemistry ,Particle ,Physical chemistry ,General Materials Science - Abstract
Diffusion of corrosive particles inside inhibitor films consisting of 2-mercaptobenzimidazole (2-SH-BI), 2-aminobenzimidazole (2-NH2-BI), 2-methylbenzimidazole (2-CH3-BI), and benzimidazole (BI) was investigated by molecular dynamics simulation. Diffusion coefficients of various corrosive particles in the films were calculated, following the same order of 2-SH-BI 2-NH2-BI > 2-CH3-BI > BI, which is in good accordance with published experimental results.
- Published
- 2011
- Full Text
- View/download PDF
44. Theoretical evaluation of corrosion inhibition performance of imidazoline compounds with different hydrophilic groups
- Author
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Songqing Hu, Guimin Qiao, Jun Zhang, Zhenjia Ren, Lijun Yu, and Youguo Yan
- Subjects
Materials science ,Carbon steel ,General Chemical Engineering ,Inorganic chemistry ,Imidazoline receptor ,General Chemistry ,engineering.material ,Quantum chemistry ,Molecular mechanics ,Medicinal chemistry ,Corrosion ,Corrosion inhibitor ,chemistry.chemical_compound ,chemistry ,Monolayer ,engineering ,General Materials Science ,Reactivity (chemistry) - Abstract
Corrosion inhibition performance of four 1-R-2-undecyl-imidazoline compounds (R CH 2 COOH (A), CH 2 CH 2 OH (B), CH 2 CH 2 NH 2 (C) and H (D)) for carbon steel was evaluated by quantum chemistry and molecular mechanics methods. Results indicated that the hydrophilic groups (R) have remarkable influence on molecular reactivity, binding strength between self-assembled monolayer (SAM) and Fe surface, and compactness of the inhibitor SAM. The inhibition efficiency evaluated via theoretical methods was well accorded with reported experimental ones, following the same order as A > B > C > D. This research might provide a theoretical inhibition performance evaluation approach for homologous inhibitors.
- Published
- 2011
- Full Text
- View/download PDF
45. Molecular modeling study on inhibition performance of imidazolines for mild steel in CO2 corrosion
- Author
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Songqing Hu, Guimin Qiao, Weizhao Yu, Jinxiang Liu, Jun Zhang, and Long You
- Subjects
Molecular model ,Inorganic chemistry ,General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Quantum chemistry ,Molecular mechanics ,Surfaces, Coatings and Films ,Corrosion inhibitor ,chemistry.chemical_compound ,Molecular dynamics ,Membrane ,chemistry ,Computational chemistry ,Molecule ,Reactivity (chemistry) - Abstract
Corrosion inhibiting performance of 1-hydroxyethyl-2-heptadecylimidazoline (A) and 1-aminoethyl-2-heptadecylimidazoline (B) for mild steel was evaluated by combination of quantum chemistry calculation, molecular mechanics, and molecular dynamics simulation. The calculated results by quantum chemistry method demonstrated that frontier orbitals of A and B molecules are mainly located on imidazoline rings, and molecule B possesses higher reactivity than molecule A. The calculated results by molecular mechanics and molecular dynamics simulation presented that these two inhibitor molecules could form dense and high-coverage membranes to prevent diffusion of reactive corrosive species to metal surface. Furthermore, the adsorption energy, cohesive energy, and adsorption angle demonstrated that the binding affinity and stability of B membrane was remarkably greater than that of A, which indicated that B had better inhibition performance in CO2 corrosion. The calculated results were well accorded with previous reported experimental results. These researches implied that molecular modeling might be an effective approach to assess inhibition performance, which has potential application in design of new inhibitors.
- Published
- 2010
- Full Text
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46. Atmospheric Corrosion Behavior of Extruded Aluminum Alloy 7075-T6 After Long-Term Field Testing in China
- Author
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A. Guo, Shuangqing Sun, Songqing Hu, Y. Geng, and X. Jia
- Subjects
Materials science ,Scanning electron microscope ,General Chemical Engineering ,Alloy ,Metallurgy ,chemistry.chemical_element ,General Chemistry ,Corrosion morphology ,engineering.material ,Intergranular corrosion ,Corrosion ,Exfoliation corrosion ,chemistry ,Atmospheric corrosion ,Aluminium ,engineering ,General Materials Science - Abstract
The long-term atmospheric corrosion behavior of extruded aluminum alloy 7075-T6 (UNS A97075) was investigated by weight loss, corrosion morphology, loss in mechanical properties, and corro...
- Published
- 2011
- Full Text
- View/download PDF
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