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nano Research 2016年第2期9卷 273-281页

作者： Bachir Aoun Daniela Russo Argonne National Laboratory Chicago IL 60439 USA CNR-IOM c/o Institut Laue-Langevin 38400 Grenoble France Institut Lumiere Matiere Universite de Lyon 69622 Lyon France

Molecular dynamics simulations have been used to investigate the confinement packing characteristics of small hydrophilic （N-acetyl-glycine-methylamide, Nagma） and hydrophobic （N-acetyl-leucine-methylamide, Nalma） biomolecules in large diameter single-wall carbon nanotubes （SWCNTs）. We find that hydrophilic biomolecules easily fill the nanotube and self organize into a geometrical configuration which reminds the water structural organization under SWCNT confinement. The packing of hydrophilic biomolecules inside the cylinder confines all water molecules in its core, which enhances their mobility. Conversely, hydrophobic biomolecules accommodate into the nanotubes with a trend for homogeneous filling, which generate unstable small pockets of water and drive toward a state of dehydration. These results shed light on key parameters important for the encapsulation of biomolecules with direct relevance for long-term storage and prevention of degradation.

关键词： nano-confinement protein folding hydration water carbon nanotube drug delivery

Robust architecture of 2D nano Mg-based borohydride on graphene with superior reversible hydrogen storage performance

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Journal of Materials Science & Technology 2023年第15期146卷 121-130页

作者： Xuancheng Wang Yuxiao Jia Xuezhang Xiao Panpan Zhou Jiapeng Bi Jiacheng Qi Ling Lv Fen Xu Lixian Sun Lixin Chen State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials School of Material Science and EngineeringGuilin University of Electronic TechnologyGuilin 541004China Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province Hangzhou 310013China

Efficient technical strategies to synthesize hydrides with high capacity and favorable reversibility are significant for the development of novel energy ***,nano Mg-based borohydride,Mg(BH_(4))_(2),with robust architecture was designed and prepared by confining on graphene through a solution selfconfinement *** Mg(BH_(4))_(2) confined on graphene displays a wrinkled 2D nano layer morphology within 8.8 nm *** 2D nano Mg(BH_(4))_(2) can start dehydrogenation at 67.9℃ with a high capacity of 12.0 wt.%,which is 190.5℃ lower than pristine Mg(BH_(4))_(2).The isothermal dehydrogenation tests and kinetics fitting results indicate the 2D nano Mg(BH_(4))_(2) possesses much-enhanced dehydrogenation kinetics of 31.3 kJ/mol activation energy,which is only half of pristine Mg(BH_(4))_(2).The thermodynamics of the 2D nano Mg(BH_(4))_(2) is also verified by PCT tests,of which Gibbs free energy value for the confined 2D nano Mg(BH_(4))_(2) is estimated to be-18.01 kJ/mol H_(2),lower than-16.36 kJ/mol H_(2) of pristine Mg(BH_(4))_(2).Importantly,the reversibility of the confined 2D nano Mg(BH_(4))_(2) is significantly enhanced to over 90%capacity retention with relatively kinetics stability during 10 *** mechanism analyses manifest that Mg(BH_(4))_(2) exhibits stable 2D nano morphology during 10 cyclic tests,resulting in the greatly reduced H diffusion path and the improved de/rehydrogenation kinetics of the 2D nano Mg(BH_(4))_(2).Based on theoretical calculations of Mg(BH_(4))_(2) and the intermediate MgB12H12 confined on graphene,the charge transfer status of both samples is modified to facilitate de/rehydrogenation,thus leading to the significant thermodynamic improvements of the reversible hydrogen storage performances for 2D nano Mg(BH_(4))_(2).Such investigation of the Mg-based borohydride will illuminate prospective technical research of energy storage materials.

关键词： Mg(BH_(4))_(2) nano-confinement Kinetics Thermodynamics Reversible hydrogen storage

Oscillating friction of nanoscale capillary bridge

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Friction 2022年第2期10卷 200-208页

作者： Shuai WU Yuqing HE Quanshui ZHENG Ming MA Department of Engineering Mechanics.Tsinghua University Beijing 100084China Center for nano and Micro Mechanics Tsinghua University.Beijing 100084China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084.China Department of Mechanical Engineering.Tsinghua University Beijing 100084China

The presence of a capillary bridge between solid surfaces is ubiquitous under ambient ***,it leads to a continuous decrease of friction as a function of bridge ***,using molecular dynamics we show that for a capillary bridge with a small radius confined between two hydrophilic elastic solid surfaces,the friction oscillates greatly when decreasing the bridge *** underlying mechanism is revealed to be a periodic ordered-disordered transition at the liquid–solid *** transition is caused by the balance between the surface tension of the liquid–vapor interface and the elasticity of the *** balance introduces a critical size below which the friction *** on the mechanism revealed,a parameter-free analytical model for the oscillating friction was derived and found to be in excellent agreement with the simulation *** results describe an interesting frictional phenomenon at the nanoscale,which is most prominent for layered materials.

关键词： capillary bridge nano-confinement elasticity atomically smooth surface

nanostructured MXene-based materials for boosting hydrogen sorption properties of Mg/MgH_(2)

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Materials Reports(Energy) 2024年第1期4卷 58-68页

作者： Yingyan Zhao Bolun Wang Li Ren Yinghui Li Xi Lin Qiuyu Zhang Zhigang Hu Jianxin Zou National Engineering Research Center of Light Alloys Net Forming&State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai200240PR China Shanghai Engineering Research Center of Mg Materials and Applications&School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai200240PR China Shanghai Key Laboratory of Hydrogen Science&Center of Hydrogen Science Shanghai Jiao Tong UniversityShanghai200240PR China

Hydrogen holds the advantages of high energy density,great natural abundance and zero emission,making it suitable for large scale and long term energy storage,while its safe and efficient storage is still *** various solid state hydrogen storage materials,MgH_(2) is promising for industrial applications due to its high gravimetric and volumetric hydrogen densities and the abundance of Mg on ***,the practical application of MgH_(2) has been limited by its stable thermodynamics and slow hydrogen desorption *** is considered as a promising approach for improving the hydrogen storage performance of MgH_(2) and bringing it closer to the requirements of commercial *** is worth mentioning that the recently emerging two-dimensional material,MXene,has showcased exceptional catalytic abilities in modifying the hydrogen storage properties of MgH_(2).Besides,MXene possesses a high surface area,excellent chemical/physical stability,and negatively charged terminating groups,making it an ideal support for the"nanoconfinement"of MgH_(2) or highly active ***,we endeavor to provide a comprehensive overview of recent investigations on MXene-based catalysts and MXene supports for improving the hydrogen sorption properties of Mg/MgH_(2).The mechanisms of hydrogen sorption involved in Mg-MXene based composites are highlighted with special emphases on thermodynamics,kinetics,and catalytic *** aim of this work is to provide a comprehensive and objective review of researches on the development of high-performance catalysts/supports to improve hydrogen storage performances of Mg/MgH_(2) and to identify the opportunities and challenges for future applications.

关键词： Magnesium-based hydride MXene Catalytic modification nano-confinement Hydrogen storage performance

Storage dynamics of ions on graphene

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Interdisciplinary Materials 2024年第2期3卷 189-202页

作者： Minghao Guo Kun Ni Yanwu Zhu Key Laboratory of Precision and Intelligent Chemistry Department of Materials Science and EngineeringSchool of Chemistry and Materials ScienceHefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefeiAnhuiChina

Carbon has been widely utilized as electrode in electrochemical energy storage,relying on the interaction between ions and *** performance of a carbon electrode is determined by a variety of factors including the structural features of carbon material and the behavior of ions adsorbed on the carbon surface in the specific *** the fundamental unit of graphitic carbons,graphene has been employed as a model to understand the energy storage mechanism of carbon materials through various experimental and computational methods,ex‐situ or in‐*** this article,we provide a succinct overview of the state‐of‐the‐art proceedings on the ion storage mechanism on *** include the structure engineering of carbons,electric gating effect of ions,ion dynamics on the interface or in the confined space,and specifically lithium‐ion storage/reaction on *** aim is to facilitate the understanding of electrochemistry on carbon electrodes.

关键词： graphene ion dynamics ion storage ionic gating nano-confinement

Recyclable nanocellulose-confined palladium nanoparticles with enhanced room-temperature catalytic activity and chemoselectivity

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Science China Materials 2021年第3期64卷 621-630页

作者： Juan Meng Yongzhuang Liu Xiaochao Shi Wenshuai Chen Xianquan Zhang Haipeng Yu Key Laboratory of Bio-based Material Science and Technology of Ministry of Education Northeast Forestry UniversityHarbin150040China

We describe the synthesis of even-dispersed palladium nanoparticles(Pd NPs)confined within a cellulose nanofiber(CNF)matrix for developing a high-performance and recyclable *** CNF matrix was composed of CNF-assembled mesoporous nanosheets and appeared as soft and hydrophilic *** Pd NPs(∼6 nm)with high-loading(9.6 wt%)were in situ grown on these mesoporous nanosheets,and their dense spatial distributions were likely to generate nano-confinement catalytic effects on the ***,the CNF-confined Pd NPs(CNF-Pd)exhibited an enhanced room-temperature catalytic activity on the model reaction of 4-nitrophenol hydrogenation with a highest rate constant of 8.8×10^−3 s^−1 and turnover frequency of 2640 h The CNF Pd catalyst possessed good chemical stability and recyclability in aqueous media which could be reused for at least six cycles without losing ***,chemoselective reduction of 3 nitrostyrene was achieved with high yield(80%–98%)of 3-aminostyrene in alcohol/water ***,this work demonstrates a positive nanoconfinement effect of CNFs for developing stable and recyclable metal NP catalysts.

关键词： nanocellulose deep eutectic solvents palladium nanoparticles catalysts nano-confinement