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Friction reactions induced by selective hydrogenation of textured surface under lubricant conditions

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Friction 2024年第1期12卷 174-184页

作者： Naizhou DU Xubing WEI Xiaowei LI Zan CHEN Shiqi LU Jiaqing DING Cunao FENG Kai CHEN Jianghao QIAO dekun zhang Kwang-Ryeol LEE Tiancai zhang School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201China Computational Science Center Korea Institute of Science and TechnologySeoul 136-791Republic of Korea Technology Development Department Shipbuilding Technology Research InstituteShanghai 200032China

The passivation of hydrogen atoms and the conformation of textured surfaces under oil-lubricated conditions are effective strategies to obtain amorphous carbon(a-C)films with extremely low friction.It is critical to understanding the influence mechanism of selective surface hydrogenation on the tribological behaviors of textured a-C film under oil-lubricated conditions.In particular,the interactions of hydrogen atoms and lubricants are confusing,which is enslaved to the in situ characterization technique.The reactive molecular dynamics(RMD)simulations were conducted to analyze the friction response of textured a-C films with selective hydrogenation surfaces under oil-lubricated conditions.The results indicate that the existence of hydrogen atoms on specific bump sites significantly decreases the friction coefficient(μ)of textured a-C film,which is highly dependent on the surface hydrogen content.The repulsion between hydrogen atoms and lubricant molecules prompts the formation of a dense lubricant film on the surface of the mating material.Interestingly,with the enhancement of the surface hydrogen content,the passivation of the friction interface and the repulsion between hydrogen atoms and lubricants play dominant roles in reducing the friction coefficient instead of hydrodynamic lubrication.

关键词： textured amorphous carbon(a-C) selective hydrogenation oil lubrication friction mechanism reactive molecular dynamics(RMD)

Textured Perovskite/Silicon Tandem Solar Cells Achieving Over 30% Efficiency Promoted by 4-Fluorobenzylamine Hydroiodide

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Nano-Micro Letters 2024年第9期16卷 557-570页

作者： Jingjing Liu Biao Shi Qiaojing Xu Yucheng Li Yuxiang Li Pengfei Liu Zetong SunLi Xuejiao Wang Cong Sun Wei Han Diannan Li Sanlong Wang dekun zhang Guangwu Li Xiaona Du Ying Zhao Xiaodan zhang Renewable Energy Conversion and Storage Center Solar Energy Conversion CenterInstitute of Photoelectronic Thin Film Devices and TechnologyNankai UniversityTianjin 300350People’s Republic of China Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Tianjin 300350People’s Republic of China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192People’s Republic of China Engineering Research Center of Thin Film Photoelectronic Technology of Ministry of Education Tianjin 300350People’s Republic of China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072People’s Republic of China Center of Single‑Molecule Sciences Institute of Modern OpticsTianjin Key Laboratory of Micro‑Scale Optical Information Science and TechnologyCollege of Electronic Information and Optical EngineeringNankai University38 Tongyan RoadJinnan DistrictTianjin 300350People’s Republic of China Shenzhen Research Institute of Nankai University 16Th FloorYantian Science and Technology BuildingHaishan StreetYantian DistrictShenzhen 518083People’s Republic of China

Monolithic textured perovskite/silicon tandem solar cells(TSCs)are expected to achieve maximum light capture at the lowest cost,potentially exhibiting the best power conversion efficiency.However,it is challenging to fabricate high-quality perovskite films and preferred crystal orientation on commercially textured silicon substrates with micrometersize pyramids.Here,we introduced a bulky organic molecule(4-fluorobenzylamine hydroiodide(F-PMAI))as a perovskite additive.It is found that F-PMAI can retard the crystallization process of perovskite film through hydrogen bond interaction between F^(−)and FA^(+)and reduce(111)facet surface energy due to enhanced adsorption energy of F-PMAI on the(111)facet.Besides,the bulky molecular is extruded to the bottom and top of perovskite film after crystal growth,which can passivate interface defects through strong interaction between F-PMA+and undercoordinated Pb^(2+)/I^(−).As a result,the additive facilitates the formation of large perovskite grains and(111)preferred orientation with a reduced trap-state density,thereby promoting charge carrier transportation,and enhancing device performance and stability.The perovskite/silicon TSCs achieved a champion efficiency of 30.05%based on a silicon thin film tunneling junction.In addition,the devices exhibit excellent longterm thermal and light stability without encapsulation.This work provides an effective strategy for achieving efficient and stable TSCs.

关键词： Perovskite crystallization (111)preferred orientation Defect passivation Perovskite/silicon tandem solar cells

Optimization study of station track utilization in high-speed railroad based on constraints of control in random origin and process

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Railway Sciences 2024年第3期3卷 332-343页

作者： Yajing Zheng dekun zhang School of Civil Engineering and Transportation South China University of TechnologyGuangzhouChina

Purpose-The purpose of this paper is to eliminate the fluctuations in train arrival and departure times caused by skewed distributions in interval operation times.These fluctuations arise from random origin and process factors during interval operations and can accumulate over multiple intervals.The aim is to enhance the robustness of high-speed rail station arrival and departure track utilization schemes.Design/methodologylapproach-To achieve this objective,the paper simulates actual train operations,incorporating the fluctuations in interval operation times into the utilization of arrival and departure tracks at the station.The Monte Carlo simulation method is adopted to solve this problem.This approach transforms a nonlinear model,which includes constraints from probability distribution functions and is difficult to solve directly,into a linear programming model that is easier to handle.The method then linearly weights two objectives to optimize the solution.Findings-Through the application of Monte Carlo simulation,the study successfully converts the complex nonlinear model with probability distribution function constraints into a manageable linear programming model.By continuously adjusting the weighting coefficients of the linear objectives,the method is able to optimize the Pareto solution.Notably,this approach does not require extensive scene data to obtain a satisfactory Pareto solution set.Originality/value-The paper contributes to the field by introducing a novel method for optimizing high-speed rail station arrival and departure track utilization in the presence of fluctuations in interval operation times.The use of Monte Carlo simulation to transform the problem into a tractable linear programming model represents a significant advancement.Furthermore,the method's ability to produce satisfactory Pareto solutions without relying on extensive data sets adds to its practical value and applicability in real-world scenarios.

关键词： Control in random origin Control in random process High-speed railroad station Arrival and departure track utilization Optimization Paper type Research paper

Wear mechanism and debris analysis of PEEK as an alternative to CoCrMo in the femoral component of total knee replacement

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Friction 2023年第10期11卷 1845-1861页

作者： Xinyue zhang Tao zhang Kai CHEN Handong XU Cunao FENG dekun zhang School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China School of Materials and Physics China University of Mining and TechnologyXuzhou 221116China

The polyetheretherketone(PEEK)-highly cross-linked polyethylene(XLPE),all-polymer knee prosthesis has excellent prospects for replacing the traditional metal/ceramic-polyethylene joint prosthesis,improving the service life of the joint prosthesis and the quality of patients’life.The long-term wear mechanism of PEEK-XLPE knee joint prosthesis is comprehensively evaluated from wear amount,wear morphology,and wear debris compared to that of CoCrMo-XLPE joint prosthesis.After 5 million cycles of in vitro wear,the wear loss of XLPE in PEEK-XLPE(30.9±3.2 mg)is lower than that of XLPE in CoCrMo-XLPE(32.1±3.1 mg).Compared to the XLPE in CoCrMo-XLPE,the plastic deformation of XLPE in PEEK-XLPE is more severe in the early stage,and the adhesive peeling and adhesion are lighter in the later stage.The size distribution of XLPE wear debris in PEEK-XLPE is relatively dispersed,which in CoCrMo-XLPE is relatively concentrated.Wear debris is mainly flake and block debris,and the wear mechanism of XLPE was abrasive wear.The wear volume per unit area of PEEK femoral condyle(10.45×10^(5)μm^(3)/mm^(2))is higher than that of CoCrMo(8.32×10^(5)μm^(3)/mm^(2)).The PEEK surface is mainly furrows and adhesions,while the CoCrMo surface is mainly furrows and corrosion spots.The PEEK wear debris is mainly in flakes and blocks,and the CoCrMo wear debris is mainly in the shape of rods and blocks.The wear mechanism of PEEK is abrasive wear and adhesion,and that of CoCrMo is abrasive wear and corrosion.

关键词： polyetheretherketone(PEEK)-highly cross-linked polyethylene(XLPE) cobalt-chromium-molybdenum(CoCrMo)-XLPE wear debris wear mechanism

Tribo-corrosion interaction of the parallel steel wires in the suspension bridges

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摩擦:英文版 2023年第12期11卷 2221-2237页

作者： Bo WANG Dagang WANG Hailang CHONG Guozheng XIE dekun zhang Shirong GE School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China School of Materials and Physics China University of Mining and TechnologyXuzhou 221116China College of Mechatronic Engineering China University of Mining and Technology(Beijing)Beijing 100083China

The effect of contact load and relative displacement on tribo-corrosion interaction of parallel steel wires of main cable in the suspension bridge was investigated in this study.A self-made tribo-corrosion test bench was employed to conduct tribo-corrosion tests of parallel steel wires in 3.5%(wt%)NaCl solution and deionized water under different contact loads and different relative displacements.The friction coefficient and wear coefficient of wires were presented.Electrochemical corrosion behavior(Tafel polarization curves,Nyquist diagram,and equivalent circuit diagram)was characterized by electrochemical analyzer.Wear morphology was observed by scanning electron microscope.Wear volume loss and corrosion‒wear interaction were quantitatively demonstrated by high-precision weighing balance.The results show that the electrochemical corrosion ability of the steel wires increases with the increase of the contact load or relative displacement.The increased contact load or relative displacement increases the volume loss of corrosion‒wear and pure wear,but decreases the wear coefficient.The wear mechanisms in 3.5%NaCl solution are adhesive wear,abrasive wear,and corrosive wear as compared to adhesive wear and abrasive wear in deionized water under different contact loads.The wear mechanisms of parallel steel wires are slightly different under different relative displacements.But the main wear mechanisms are similar to that under different contact loads.The interaction effects of corrosion and wear produced by the contact load and relative displacement are all the synergistic effects.

关键词： main cable parallel steel wires friction corrosion‒wear interaction

Kinetic Resolution of 1,2-Diamines via Organocatalyzed Asymmetric Electrophilic Aminations of Anilines

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Chinese Journal of Chemistry 2022年第14期40卷 1674-1680页

作者： Jinglei Xie Zheng Guo Wei Liu dekun zhang Yu-Peng He Xiaoyu Yang School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Key Laboratory of Petrochemical Catalytic Science and Technology Liaoning Shihua UniversityFushunLiaoning 113001China Universityof Chinese Academy of Sciences Bejing 100049China State Key Laboratory of Fine Chemicals Ningbo Institute of Dalian University of TechnologyNingboZhejiang 315016China

An efficient kinetic resolution(KR)protocol for 1,2-diamines has been developed through asymmetric electrophilic aminations of anilines enabled by chiral phosphoric acid catalysis.A wide array of substituted 1,2-diamines were compatible with this method,generating both the recovered staring materials and the amination products with high enantioselectivities(with s-factor up to 218).Notably,this method is amenable to the kinetic resolution of 1,2-diamines bearingα-tertiary amine moieties,which represents the first KR of this type of 1,2-diamines.Facile removal of the introduced hydrazine group and oxidative cleavage of the N-aryl group to release the free primary amine demonstrate the value of this method.

关键词： Asymmetric catalysis 1,2-Diamines Kinetic resolution Chiral phosphoric acids Amination

Cartilage-bone inspired the construction of soft-hard composite material with excellent interfacial binding performance and low friction for artificial joints

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Friction 2023年第7期11卷 1177-1193页

作者： Qin CHEN Xinyue zhang Siyu LIU Kai CHEN Cunao FENG Xiaowei LI Jianwei QI Yong LUO Hongtao LIU dekun zhang School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

Inspired by the cartilage-bone structure in natural joints,soft-hard integrated materials have received extensive attention,which are the most promising candidates for artificial joints due to their combination of excellent load-bearing properties and lubricating properties.The latest progress showed that the combination of hydrogel and titanium alloy can realize a bionic natural joint lubrication system on the surface of titanium alloy.However,obtaining a tough interface between the hydrogel(soft and wet)and the titanium substrate(hard and dry)is still a great challenge.Here,we designed a"soft(hydrogel)-hard(Ti6Al4V)"integrated material with outstanding combination,which simulates the structure and function of cartilage-bone in the natural joint.The load-bearing properties,binding performance,and tribological behaviors for different forms of the soft-hard integrated materials were investigated.The results showed that the hydrogel layer and Ti6Al4V substrate possess ultra-high interfacial toughness(3,900 J/m^(2)).In addition,the combination of the hydrogel layer and Ti6Al4V substrate provided a good lubrication system to endow the"soft(hydrogel)-hard(Ti6Al4V)"integrated material with high load-bearing and excellent tribological properties.Therefore,this study provided an effective strategy for prolonging the service life of Ti6Al4V in the biomedical field.

关键词： Ti6Al4V alloy hydrogel soft-hard interface friction

Insights into friction behavior of textured amorphous carbon and lubricant composite system: Dependence on the lubricant viscosity and textured shape

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Progress in Natural Science:Materials International 2023年第5期33卷 616-624页

作者： Jiaqing Ding Naizhou Du Xubing Wei Xiaowei Li Zan Chen Shiqi Lu Haolin zhang Cunao Feng Kai Chen Jianghao Qiao dekun zhang Kwang-Ryeol Lee School of Materials Science and Physics China University of Mining and Technology Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective Technologies Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Computational Science Center Korea Institute of Science and Technology

Combining textured amorphous carbon(a-C) film with lubricant achieves ultra-low friction to improve the mechanical component’s service life. However, the coupling influence of lubricant viscosity and textured shape on friction behavior and interfacial transformation are still unclear. In this work, the evolution of friction performance with Poly-alpha-olefin viscosities and its dependence on textured shapes were investigated by reactive molecular dynamics simulation. Results reveal that as the textured shape is fixed, increasing the lubricant viscosity causes friction coefficient to decline first and then increase, due to the hydrodynamic lubrication and regional aggregation of lubricant. While under same lubricant condition, rectangular textured systems exhibit lower friction coefficient than circular textured ones, attributing to the formation of stable lubricant film without serious aggregation.

关键词： Amorphous carbon Surface texture Lubricant Reactive molecular dynamics

A Facile Modifier-free Approach to Fabricate Antistatic Superhydrophobic Composite Coatings with Remarkable Thermal Stability and Corrosion Resistance

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Journal of Bionic Engineering 2020年第3期17卷 421-435页

作者： Xiang Liu dekun zhang Zhiguang Guo School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China School of Materials Science and Engineering China University of Mining and TechnologyXuzhou 221116China Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials Hubei UniversityWuhan 430062China

Research on antistatic superhydrophobic surfaces has attracted widespread attention in some fields.However,in the application of superhydrophobic materials,fabricating stable and practical superhydrophobic surfaces through facile and low-cost approaches still faces considerable challenges.Herein,a polyphenylene sulfide(PPS)-based antistatic superhydrophobic composite coating with a high water contact angle(166°)and a low sliding angle(2°)was fabricated on a Q345 steel surface through a simple spray-coating method without any modifier.Furthermore,the as-prepared superhydrophobic coating also displayed excellent superhydrophobicity for water droplets at different pH values,as well as self-cleaning,anti-fouling and anti-icing properties.Importantly,the superhydrophobic coating still exhibited superhydrophobicity after calcination at 350°C for 1 h,indicating its outstanding thermal stability.Excellent antistatic and anticorrosion properties were obtained on the prepared coating surface,which allows the coating to be applied under harsh conditions.Benefiting from the above characteristics,compared with the commercial coating,the as-obtained antistatic superhydrophobic coating may be applied more widely in related fields.

关键词： no-modifier superhydrophobicity thermal stability antistatic property anticorrosion