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Chinese Journal of Polymer science 2005年第5期23卷 479-485页

作者： Kai Kang Cheng-you Kan Yi Du de-shan liu department of chemical engineering,school of materials science and engineering,tsinghua university,beijing 100084,china department of chemical engineering School of Materials Science and Engineering Tsinghua University Beijing 100084 China

Soap-free poly（methyl methacrylate-ethyl acrylate-methacrylic acid） latex particles with narrow size distribution were synthesized by seeded emulsion polymerization, and the porous particles were created by a stepwise alkali/acid treatment method. Effects of acid treatment conditions on the particle morphology were investigated. Results show that one to three pores were formed inside most of particles after post-treatment. At pH 7.0, when the treatment temperature was lower than 70℃, the size of particles and the volume of pores remained almost unchanged, and these two values increased significantly when the temperature was higher than 70℃. Both the particle size and the pore volume decreased with the increase of initial pH value and treatment time in the acid treatment. As the pH was below 4.0 and the treatment time was longer than 180 min, the particles shrunk in size.

关键词： Soap-free emulsion polymerization Particle morphology Porous structure Acid treatment Methyl methacrylate based copolymer.

Synthesis of Bis(4'-hydroxyphenyl)-toluene-2, 4-diurethane for Main Chain Liquid Crystalline Poly(urethane-ester)s

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Chinese chemical Letters 1998年第5期9卷 439-442页

作者： Yan Qing LIAN Ming Qi LI Qi Xiang ZHOU de shan liu(Institute of Polymer science and engineering, department of chemical engineering,tsinghua university, beijing 100084) Inst. of Poly. Sci. and engineering Department of Chemical Engineering Tsinghua University Beijing 100084 China

A new methodology was advanced that mesogenic cores appeared after theformation of urethane groups and during the monomer-to-polymer transition. A newdiphenol monomer, bis(4'-hydroxy-phenyl)-toluene-2 (BHPTU), was obtainedby the reaction of 2,4-tolulene diisocyanate with hydroquinone in dioxane or N,N-dimethyl-acetandde. The reaction process was monitored by FTIR, and the product was investigated bylH NMR and elemental analysis (EA). A liquid crystalline poly(urethane-ester) was obtainedusing the BHPTU monomer.

关键词： liquid crystalline polymer poly(urethane-ester) synthesis

Oxidation Behavior of Micro-Crystalline Coatings of 310S Stainless Steel

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International Journal of Minerals,Metallurgy and materials 1998年第1期12卷 51-56页

作者： Zhenyu liu Wei Gao Karl Dahm Yedong He (department of chemical and materials engineering, The university of Auckland, New Zealand)(materials science and engineering school, university of science and Technology beijing, beijing 100083, china) department of chemical and materials engineering University of Auckland Beijing New Zealand materials science and engineering school University of Science and Technology Beijing Beijing 100083 China

Micro-crystalline coatings of 310S stainless steels were produced by unbalanced magnetron sputter deposition. Isothermal oxidation behavior of the coated and uncoated specimens has been studied using a thermogravimetric analysis (TGA) station. The oxidation time was 50h and the temperature was 1 000℃. The oxidation rates of thecoated specimens was found to be much lower than the uncoated specimens after 50 h of oxidation. The oxidationkinetic curves of the coated specimens consisted of three stages : approximately parabolic at the first stage, speedingup at the second stage, and slow down at the third stage. The increase of the oxidation rate at the second stage nasattributed to the fast diffuison of Fe though the fine grained Cr2O3 layer formed on the micro-crystalline *** top view and cross-section microstructures of the oxides formed on the coated and the uncoated specimens werestudied with SEM and EDS. It was observed that the nucleation of oxide on the coated specimens was muchenhanced at the initial oxidation stage. This was explained as the result of reduction in the critical free energychange and increase in the supply of chromium ions.

关键词： oxidation 310S stainless steel magnetron sputter deposition oxide nucleation

A General Procedure for Surface Modification of Nano-alumina and Its Application to dendrimers

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Journal of Wuhan university of Technology(materials science) 2007年第3期22卷 453-456页

作者：王斌郭朝霞 Institute of Polymer science and engineering Department of Chemical EngineeringSchool of Materials Science and EngineeringTsinghua University

A general procedure for surface modification of nano-alumina using N, N＇-dicyclohexyl- carbodiimide （DCC） mediated amidation is reported. Aliphatic and aromatic carboxylic acids reacted smoothly with nano-alumina pretreated with 3-aminopropyltriethoxysilane in the presence of DCC, giving modified aluminas having organic surfaces. The grafted aluminas have been characterized qualitatively by FT-IR or ^13C CPMAS NMR spectroscopy, and quantitatively by thermogravimetric analysis and elemental analysis. The procedure was applied to polyether dendrons bearing carboxyl groups at the focal points, giving successful grafting of dendrimers onto nano-alumina.

关键词： nano-alumina N, N'-dicyclohexyl-carbodiimide (DCC) surface modification dendrimers

Hexafluoro-2-propanol as a potent cosolvent for chemical ligation of membrane proteins

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science china Chemistry 2011年第1期54卷 110-116页

作者： SHEN Fei,TANG shan & liu Lei department of Chemistry,university of science and Technology of china,Hefei 230026,china Key Laboratory of Bioorganic Phosphorus Chemistry and chemical Biology,Ministry of Education department of Chemistry,tsinghua university.beijing 100084,china department of Chemistry University of Science and Technology of China Hefei China Key Laboratory of Bioorganic Phosphorus Chemistry and chemical Biology Ministry of Education department of Chemistry Tsinghua University Beijing China

The study on membrane proteins is an important challenge mainly because of their very poor solubility in various *** traditional recombinant expression strategy and the native chemical ligation method both have difficulty in generating sufficient amounts of desired proteins with high *** studies have shown that multiply fluorinated alcohols exhibit good ability to dissolve difficult peptide sequences,especially hexafluoro-2-propanol (HFIP).In the present study we systematically studied the capability of solvents containing different percentage of HFIP in dissolving transmembrane *** both HPLC and UV analyses we concluded that 60% HFIP/8 M urea constituted a good solvent *** this solvent system we also optimized conditions to perform native chemical ligation (NCL).Under the optimized conditions we successfully achieved NCL’s for both dipeptide formation and the synthesis of a model protein (Trifolitoxin).These results suggested that HFIP was a potential cosolvent that could be used in the ligation of poorly soluble peptides for the generation of membrane proteins.

关键词： membrane protein native chemical ligation alternative solvent hexafluoro-2-propanol

Strong hetero-interface interaction in 2D/2D WSe_(2)/ZnIn_(2)S_(4) heterostructures for highly-efficient photocatalytic hydrogen generation

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Journal of Energy Chemistry 2024年第10期97卷 379-387,I0008页

作者： Xu Guo Xing liu jing shan Zhuo Xu Zhiming Fang Lu Wang Shengzhong liu school of Energy Powerand Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China Shaanxi Key Laboratory for Advanced Energy devices School of Materials Science and EngineeringShanxi Normal UniversityXi'an 710119ShanxiChina Qinghai Advanced Energy Storage Laboratory SPIC Qinghai Photovoltaic Industry Innovation Center Co.Ltd.State Power Investment CorporationXining 810oo7QinghaiChina Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Center of materials science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China

Green hydrogen is urgently required for sustainable development of human beings and rational construction of heterostructures holds great promising for photocatalytic hydrogen ***,2D/2D WSe_(2)/ZnIn_(2)S_(4) heterostructures with strong hetero-interface interaction and abundant contact were constructed via an impregnation-annealing *** charge transfer from ZnIn_(2)S_(4) to WSe_(2)was evidenced by transient absorption spectroscopy in crafted heterostructures owing to the tight and2D face-to-face *** a result,the prepared WSe_(2)/ZnIn_(2)S_(4) heterostructures exhibited boosted photocatalytic performance and a highest hydrogen evolution rate of 3.377 mmol/(g h)was achieved with an apparent quantum yield of 45.7%at 420 *** work not only provides new strategies to achieve efficient 2D/2D heterostructures but also paves the way for the development of green hydrogen in the future.

关键词： Strong hetero-interface interaction in 2D/2D WSe_(2)/ZnIn_(2)S_(4) heterostructures for highly-efficient photocatalytic hydrogen generation

Manufacturing process of water-soluble salt-based ceramic cores based on vat photopolymerization

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Journal of Advanced Ceramics 2024年第5期13卷 652-665页

作者： Yuzhen Zhang Wenyan Duan Yue Gu Xingyao Sun shan Li Bingshan liu Gong Wang Key Laboratory of Space Manufacturing Technology(SMT) Technology and Engineering Center for Space UtilizationChinese Academy of SciencesBeijing 100094China university of Chinese Academy of sciences Beijing 100049China Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing Changchun University of Science and TechnologyChangchun 130022China

Water-soluble salt-based ceramic cores can be recycled and have excellent high-temperature chemical *** this work,vat photopolymerization was successfully applied to water-soluble salt-based ceramic cores for the first *** powder raw materials of the printing suspension were sodium chloride and ***-precision green bodies were manufactured by optimizing suspensions and *** addition,the postprocessing method was optimized according to the microstructure and mechanical *** sintered part had a high bending strength and smooth ***,the dissolution rate and moisture resistance were compared under different dissolution and storage *** to traditional manufacturing methods,vat photopolymerization enables the production of complex structures without molds and reduces production *** technology is suitable for the rapid iteration of complex structural parts and can be applied to precision parts in aerospace,military,and other technical fields with high cost-effectiveness and sustainability.

关键词： vat photopolymerization water-soluble salt-based ceramic cores defect formation control accuracy moisture rate

dehydration-triggered structural phase transition-associated ferroelectricity in a hybrid perovskite-type crystal

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Chinese chemical Letters 2024年第10期35卷 461-464页

作者： Zhi-Yuan Yue Hua-Kai Li Na Wang shan-shan liu Le-Ping Miao Heng-Yun Ye Chao Shi Chaotic Matter science Research Center Jiangxi University of Science and TechnologyGanzhou 341000China

Since the appearance of Rochelle salt,ferroelectrics have received extensive attention from researchers due to they are playing an important role in sensors,memories,mechanical actuation,and so *** recent years,with the rapid development of molecular ferroelectrics,high-performance molecular ferroelectrics have become effective complement to inorganic ***,compared with inorganic ferroelectrics,the family of molecular ferroelectrics is relatively scarce,and exploring highperformance ferroelectric materials through new synthesis strategies has become the trend of molecular ***,we successfully transformed non-polar material 1(2-H_(2)PCA)_(2)(H_(2)O)CdCl_(6)(2-H_(2)PCA=2-picolylamine cation)into polar material 2(2-H_(2)PCA)2CdCl_(6)by single-crystal to single-crystal transformation(SCSCT).Meanwhile,2 exhibits clear ferroelectricity with a high-temperature Tc of 378 K,a Ps of 1.18μC/cm^(2)at 300 *** work not only realizes the purpose of synthesizing ferroelectrics by forming polar structures by SCSCT,but also realizes the reversibility of SCSCT,which provides ideas for the construction and exploration of new molecular ferroelectrics.

关键词： Hybrid perovskite Ferroelectric materials Single-crystal to single-crystal transformation Phase transition Stimulus-structure-response

Gas-sensing properties of nanocomplex metal oxide

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Progress in Natural science:materials International 2005年第7期15卷 669-672页

作者： CHEN Liangyuan, HE Zhusheng, YAN Tao, BAI Shouli, CHEN Aifan and liu Chung Chiun ( Electronics design Center, Case Western Reserve university, Cleveland, OH 44106, USA department of Chemistry and chemical engineering, Baoji university of Arts and science, Baoji 721007, china College of science, beijing university of chemical Technology, beijing 100029, china) Electronics design Center Case Western Reserve University Cleveland OH 44106 United States department of Chemistry and chemical engineering Baoji University of Arts and Science Baoji 721007 China College of science Beijing University of Chemical Technology Beijing 100029 China

The development of CuO/CeO2 nanocomposites as the sensing material of semiconductor gas sensors is reported. CuO/CeO2 nanocomplex oxide is prepared by modified sol-gel method that uses copper nitrate, cerium nitrate and ethylene glycol as precursors. The optimized synthesis parameters and processing condition have been established. The particle size and distribution, phase morphology, specific surface, electronic states of atoms and gas sensing properties have been systematically characterized by Transmission Electron Microscope (TEM), Brunauer Emmett Teller (BET), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and gas sensitivity measurement. The results show that the sensor sensitivity depends on particle size, Cu/Ce cation ratio and calcination temperature. The effects of calcinations temperature and CuO loading on the gas sensitivity are also examined. The optimum calcination temperature and the CuO content for the highest sensitivity are 600 ℃and 12% , respectively. The combination of excellent thermal stability and tunable sensing properties through careful control of the processing parameters and selection of material composition gives rise to novel nanocomposites attractive to the sensitive and selective detection of a variety of toxic and combustible gases.

关键词： copper oxide cerium oxide nanocomposite CO gas sensitivity.

Ab initio molecular dynamics simulation of the atom packing and density of Al-Ni amorphous alloys

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science china(Technological sciences) 2010年第12期53卷 3175-3182页

作者： YU ChunYan1, HUI XiDong1, CHEN XiaoHua1, liu XingJun1, LIN deYe1, liu ZiKui2 & CHEN GuoLiang1 1 State Key Laboratory for Advanced Metals and materials, university of science and Technology beijing, beijing 100083, china 2 department of materials science and engineering, Pennsylvania State university, university Park, PA 16802, USA State Key Laboratory for Advanced Metals and materials University of Science and Technology Beijing Beijing China department of materials science and engineering Pennsylvania State University University Park USA

Al-Ni alloys have better glass forming ability (GFA) than other Al-based alloys. However, the relationship among the atomic arrangement, glass transition, packing density and composition hasn’t been systematically studied. In this paper the ab initio molecular dynamics simulation (AIMD) was performed on the atom packing and density of AlxNi100-x (x=80, 83, 85, 86, 87 and 90) alloys. The pair correlation function and Voronoi tessellation indicated that there are obvious topological and chemical short-range orders in these alloys. The topological structure consists of Al-centered icosahedra like and Ni-centered tri-capped trigonal prism (TTP) like polyhedra. There is strong chemical short-range ordering between Al and Ni atoms indicated by the bond-length of Al-Ni pair shorter than the sum of the radii of Al and Ni atoms, which increases with the increasing of Ni content. It is shown that the densities of amorphous alloys don’t agree with the linear law with a peak at x=85. Based on the features of the structure and density, it is concluded that Al-Ni alloys at x=84–86 have high GFA, which can be extended to multi-component Al-based alloys.

关键词： AIMD Al-Ni alloys density short-range order chemical short-range order