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具有规整结构和高强度的水凝胶研究进展 被引量:13
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作者 王雪珍 汪辉亮 《高分子通报》 CAS CSCD 2008年第3期1-6,共6页
人造水凝胶普遍存在结构不规整的问题,即交联点无序性分布和链节长短不一。这就导致人造水凝胶存在机械性能差、响应速度慢、溶胀之后回复性不好等缺点,大大限制了其在生物医学和工业等领域的应用范围。然而,生物凝胶却普遍具有规整的... 人造水凝胶普遍存在结构不规整的问题,即交联点无序性分布和链节长短不一。这就导致人造水凝胶存在机械性能差、响应速度慢、溶胀之后回复性不好等缺点,大大限制了其在生物医学和工业等领域的应用范围。然而,生物凝胶却普遍具有规整的微结构和优异的性能。制备具有规整结构的水凝胶已经成为一个具有挑战性的重要课题。本文综述了制备具有规整结构的高强度水凝胶的研究进展。 展开更多
关键词 水凝胶 规整结构 高强度 制备
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Metal–ligand interfaces for well-defined gold nanoclusters
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作者 Dan Yang Yating Wu +5 位作者 Zhaotong Yuan Chunmei Zhou Yihu Dai Xiaoyue Wan Yan Zhu Yanhui Yang 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第3期806-823,共18页
Ligand engineering for well-defined gold nanoclusters(Au NCs) is getting more extensive attention. Organizing the Au-ligand interfaces on gold NCs can achieve the structural and functional control. This review focuses... Ligand engineering for well-defined gold nanoclusters(Au NCs) is getting more extensive attention. Organizing the Au-ligand interfaces on gold NCs can achieve the structural and functional control. This review focuses on the Au-ligand interfaces including gold-phosphorus(Au-P), gold-sulfur(Au-S), gold-selenium(Au-Se), gold-carbon(Au-C), and gold-nitrogen(Au-N), derived from the bonding between Au atoms and the different ligands(e.g., organic phosphine, thiolate, selenolate, alkynyl,n-heterocyclic carbene and nitrogenous ligands). The formation mechanism of Au-ligand interfaces is well discussed. In addition, the effects of Au-ligand interfaces on the stability, optical property, and catalysis are also presented. We hope the advances in this research area can boost the development of Au NC sciences. 展开更多
关键词 Au nanoclusters well-defined structures metal–ligand interfaces formation mechanism structure–property correlation
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Atomically Precise Water-Soluble Gold Nanoclusters:Synthesis and Biomedical Application
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作者 Qian Yan Zhaotong Yuan +8 位作者 Yating Wu Chunmei Zhou Yihu Dai Xiaoyue Wan Dan Yang Xu Liu Nianhua Xue Yan Zhu Yanhui Yang 《Precision Chemistry》 2023年第8期468-479,共12页
Atomically precise water-soluble gold nanoclusters(Au NCs)protected by organic ligands have attracted growing attention in serving as unique nanomaterials with the potential to generate theranostic tools(bioimaging,bi... Atomically precise water-soluble gold nanoclusters(Au NCs)protected by organic ligands have attracted growing attention in serving as unique nanomaterials with the potential to generate theranostic tools(bioimaging,biosensing,and biotherapy),due to their ultrasmall size,superior photoluminescence,good biocompatibility,and nontoxicity.More importantly,Au NCs afford a well-defined atomic packing structure and molecular purity,providing a superior platform to unravel the structure−performance correlations for biodistribution,biological pharmacokinetics,and excretion of Au NCs.In this Review,we mainly survey the synthesis of water-soluble Au NCs and the recent progress in biomedicine of Au NCs,including bioimaging,biosensing,and biotherapy.The effects of ligand and size on the biomedical properties are discussed in detail.We hope that the advances in this research area can expand the applications of Au NCs in biomedicine. 展开更多
关键词 Gold nanocluster well-defined structure WATER-SOLUBLE biodiagnostic THERANOSTIC
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稀土-钛氧簇合物EuTi6,EuTi7和La2Ti14的可控合成 被引量:3
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作者 杨亚梅 伦会洁 +2 位作者 龙腊生 孔祥建 郑兰荪 《物理化学学报》 SCIE CAS CSCD 北大核心 2020年第9期124-129,共6页
相比于纳米材料,原子精度的金属簇合物具有精确的表面结构和晶体结构,更有利于在原子水平上去理解化学反应的活性与结构的关系。作为团簇的一个有趣的分支,异金属的稀土-钛氧簇合物因其有趣的化学性质引起了人们的广泛关注。但是稀土-... 相比于纳米材料,原子精度的金属簇合物具有精确的表面结构和晶体结构,更有利于在原子水平上去理解化学反应的活性与结构的关系。作为团簇的一个有趣的分支,异金属的稀土-钛氧簇合物因其有趣的化学性质引起了人们的广泛关注。但是稀土-钛氧簇合物的精准合成是目前的重要挑战,这阻碍了其性能的进一步研究。因为螯合配体可以降低Ti4+的水解速度,因此选择合适的螯合配体是制备稀土钛氧团簇的有效方法。最近,我们以螯合作用较强的3,5-二叔丁基水杨酸(H2dtbsa)为配体,稀土盐和Ti(OiPr)4为原料,通过溶剂热法成功合成了四个新的稀土-钛氧簇合物[EuTi6(μ3-O)3(OC2H5)8(dtbsa)6(Hdtbsa)]·(C2H5OH)(1),[EuTi7(μ3-O)3(μ2-OH)2(OiPr)9(dtbsa)6(Hdtbsa)Cl]·(HOiPr)3(2),[EuTi7(μ3-O)3(μ2-OH)2(OiPr)8(dtbsa)7(Hdtbsa)]·(HOiPr)2(3)和[LaTi7(μ3-O)3(μ2-OH)2(OC2H5)8(dtbsa)7(Hdtbsa)]2·(C2H5OH)4(4)。单晶分析表明,七核化合物1内核EuTi6具有三角棱柱的结构,其中Eu3+位于六个Ti4+离子形成的棱柱中心。八核化合物2和3的金属内核结构可以看作是化合物1中三棱柱的一侧连接一个Ti4+。化合物4中,Ln2Ti14的金属骨架可看作是EuTi7的二聚体。紫外-可见漫反射光谱估算的带隙值表明,簇合物1、2和3的禁带宽度值分别为2.35、2.07和2.16 eV,明显小于锐钛矿的禁带宽度值。光电响应测试发现这三种簇合物具有明显的光电响应,而且簇合物1和2的电荷分离效应好于簇合物3。为了探索这类簇合物在光催化方面的应用,我们做了在甲醇水溶液中的光催化(300–800 nm)分解水产氢实验。簇合物1、2和3的产氢率分别为112、106和87μmol?h-1?g-1,高于商用P25。粉末X射线衍射(PXRD)和热重分析(TGA)证明了簇合物的光热稳定性。本文不但提供了一种制备稀土钛氧簇合物的螯合配体策略,而且还表明稀土钛氧簇合物具有较低的带隙和光驱动的催化活性。 展开更多
关键词 稀土-钛氧簇合物 精确结构 溶剂热法 产氢 光解水
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Measurement of pore diffusion factor of porous solid materials 被引量:1
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作者 Jin-Tao Guo Ya-Qian Wei +4 位作者 Sheng-Li Chen Wei Sun Ting-Ting Fan Ming-Ri Xu Chang-Cheng Zhang 《Petroleum Science》 SCIE CAS CSCD 2022年第4期1897-1904,共8页
Internal diffusion of molecules in porous materials plays an important role in many chemical processes.However, the pore diffusion capacity of porous materials cannot be measured by conventional catalyst characterizat... Internal diffusion of molecules in porous materials plays an important role in many chemical processes.However, the pore diffusion capacity of porous materials cannot be measured by conventional catalyst characterization methods. In the present paper, a pore diffusion factor, the ratio of the diffusionconstriction factor to the pore tortuosity of the porous materials, was proposed to measure the diffusion ability of pores inside solid materials, and a method was proposed for measuring the diffusion factor using a well-defined and uniform pore size material as a reference. The diffusion factor was calculated based on the effective diffusion coefficients and the diffusion-constriction factor and pore tortuosity of the reference porous materials. The pore diffusion factor measurement can be performed at room temperature and atmospheric pressure. The pore diffusion factor of conventional porous materials was found to be much smaller than 1, indicating that there is a lot of room for improving the diffusion ability of the conventional catalysts and adsorbents, and could be significantly increased through adding small number of fibers into the conventional porous materials as template. 展开更多
关键词 Porous materials well-defined and uniform pore structure materials Internal diffusion Diffusion factor TORTUOSITY
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运用连接子化学合成特定结构功能聚合物 被引量:1
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作者 袁金颖 闫强 《高分子通报》 CAS CSCD 北大核心 2011年第4期55-67,共13页
连接子化学已经成为聚合物合成的有效途径。本文介绍了作者课题组运用连接子化学合成多种特定结构功能聚合物的研究进展,主要包括运用缩合反应、开环反应、点击化学实现连接子反应,以及可逆的连接子的设计和构筑。最后展望了连接子化学... 连接子化学已经成为聚合物合成的有效途径。本文介绍了作者课题组运用连接子化学合成多种特定结构功能聚合物的研究进展,主要包括运用缩合反应、开环反应、点击化学实现连接子反应,以及可逆的连接子的设计和构筑。最后展望了连接子化学在聚合物合成领域的发展方向。 展开更多
关键词 连接子化学 聚合物 特定结构 可控聚合 功能调控
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Restructuring of well-defined Pt-based electrode surfaces under mild electrochemical conditions
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作者 Jie Wei Wei Chen +2 位作者 Da Zhou Jun Cai Yan-Xia Chen 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第11期2792-2801,共10页
Since the 1980s,single-crystal Pt electrodes with well-defined surface structures have been deemed stable under mild electrochemical conditions(e.g.,in the potential region of electric double layers,underpotential dep... Since the 1980s,single-crystal Pt electrodes with well-defined surface structures have been deemed stable under mild electrochemical conditions(e.g.,in the potential region of electric double layers,underpotential deposition of hydrogen,or mild hydrogen evolution/OH adsorption)and have served as model electrodes for unraveling the structure-performance relation in electrocatalysis.With the advancement of in situ electrochemical microscopy/spectroscopy techniques,subtle surface restructuring under mild electrochemical conditions has been achieved in the last decade.Surface restructuring can considerably modify electrocatalytic properties by generating/destroying highly active sites,thereby interfering with the deduction of the structure-performance relation.In this review,we summarize recent progress in the restructuring of well-defined Pt(-based)electrode surfaces under mild electrochemical conditions.The importance of the meticulous structural characterization of Pt electrodes before,during,and after electrochemical measurements is demonstrated using CO adsorption/oxidation,hydrogen adsorption/evolution,and oxygen reduction as examples.The implications of present findings for correctly identifying the reaction mechanisms and kinetics of other electrocatalytic systems are also briefly discussed. 展开更多
关键词 Surface restructuring well-defined Pt electrode surface structure-performance relation In situ/operando electrochemical characterization ELECTROCATALYSIS
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Design and Synthesis of Structurally Well-Defined Functional Polyolefins via Transition Metal-Mediated Olefin Polymerization Chemistry 被引量:3
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作者 Jin-Yong Dong 《复旦学报(自然科学版)》 CAS CSCD 北大核心 2005年第5期655-656,共2页
关键词 聚烯烃 金属介质 分子结构 石蜡 聚合化学
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活性聚合改性富勒烯C_(60)在新型聚合物材料中的应用 被引量:2
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作者 李宏宇 陈志强 李效玉 《化工新型材料》 CAS CSCD 北大核心 2006年第4期60-62,共3页
富勒烯(Fullerene)由于其独特的性能,成为新型聚合物材料方面的一个研究热点,特别是通过对其家族中的典型代表C60的改性修饰,可以获得具有特殊功能的高分子材料,如光电材料和生物医药材料。本文对近几年来高分子化学中活性聚合手段对C6... 富勒烯(Fullerene)由于其独特的性能,成为新型聚合物材料方面的一个研究热点,特别是通过对其家族中的典型代表C60的改性修饰,可以获得具有特殊功能的高分子材料,如光电材料和生物医药材料。本文对近几年来高分子化学中活性聚合手段对C60的改性修饰进行了回顾。 展开更多
关键词 富勒烯改性 活性或可控聚合 结构规整
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