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Quartz crystal microbalance study of the kinetics of surface initiated polymerization

science china chemistry 2009年第12期52卷 2307-2322,1-5页

作者： CHEN XinAn zhang YaoZhong HE JianAn XIONG ChunYang MENG Yonghong JIN Gang MA hongWei department of Biomedical engineering College of EngineeringPeking UniversityBeijing 100871China National Microgravity Laboratory Institute of MechanicsChinese Academy of SciencesBeijing 100190China Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of SciencesSuzhou 215125China

Surface initiated polymerization (SIP) is a valuable tool in synthesizing functional polymer brushes,yet the kinetic understanding of SIP lags behind the development of its application. We apply quartz crystal microbalance (QCM) to address two issues that are not fully addressed yet play a central role in the rational design of functional polymer brushes,namely quantitative determination of the kinetics and the initiator efficiency (IE) of SIP. SIP are monitored online using QCM. Two quantitative frequencythickness (f-T) relations make the direct determination and comparison of the rate of polymerization possible even for different monomers. Based on the bi-termination model,the kinetics of SIP is simply described by two variables,which are related to two polymerization constants,namely a = 1/(kp,s,app-[M][R·]0) and b = kt,s,app/(kp,s,app[M]). Factors that could alter the kinetics of SIP are studied,including (i) the molecular weight of monomers,(ii) the solvent used,(iii) the initial density of the initiator,(iv) the concentration of monomer,[M],and (v) the catalyst system (ratio among the ingredients,metal,ligands,and additives). The dynamic nature of IE is also described by these two variables,IE = a/(a + bt). Instead of the molecular weight and the polydispersity,we suggest that film thickness,the two kinetic parameters (a and b),and the initial density of the initiator and IE be the parameters that characterize ultrathin polymer brushes. Besides the kinetics study of SIP,the reported method has many other applications,for example,in the fast screening of catalyst system for SIP and other polymerization systems.

关键词： surface initiated polymerization quartz crystal microbalance kinetics controlled living radical polymerization

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A Moonlighting Superpositively Charged SpyCatcher

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CCS chemistry 2023年第11期5卷 2663-2673页

作者： Tingting Yang Yajie Liu Wen-Hao Wu Rongmei Peng Wen-Bin zhang beijing National Laboratory for molecular sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenter for Soft Matter Science and EngineeringCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871 Key Laboratory of Vision Loss and Restoration Ministry of EducationBeijing 100084 department of Ophthalmology Peking University Third HospitalBeijing 100191 beijing Academy of Artificial Intelligence Beijing 100084

Genetically encoded covalent peptide tagging tools such as the SpyTag/SpyCatcher reactive pair,have been demonstrated versatile and useful for protein ***,we present a superpositively charged SpyCatcher bearing a theoretical net charge of+21 capable of accomplishing multiple unrelated independent tasks to enrich this toolbox and cultivate new *** SpyCatcher(+21)possessed stimuli-responsive reactivity toward SpyTag and could serve as a potent and general platform for the delivery of proteins,including RNaseAinto HeLa ***,the delivered RNase A caused substantial proliferation inhibition toward HeLa *** addition,the superpositively charged SpyCatcher could form coacervate with plasmid DNA for further study of gene delivery and liquid–liquid phase *** findings demonstrate the robustness of the SpyTag/SpyCatcher structure against surface mutation and the prospect of applying supercharging technology on diverse functional proteins to create moonlighting proteins.

关键词： SpyCatcher stimuli-responsive protein delivery phase separation supercharging cyclic proteins topology

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The impact of fluorination on both donor polymer and non-fullerene acceptor:The more fluorine,the merrier

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Nano Research 2019年第9期12卷 2400-2405页

作者： Nicole Bauer Qianqian zhang Jeromy James Rech Shuixing Dai Zhengxing Peng Harald Ade Jiayu Wang Xiaowei Zhan Wei You department of chemistry University of North Carolina at Chapel HillNorth Carolina 27599USA department of Materials science and engineering College of EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry EducationPeking UniversityBeijing 100871China department of Physics and ORaCEL North Carolina State UniversityRaleighNorth Carolina 27695USA

Fluorination of the donor polymer or non-fullerene acceptor (NFA) in an organic photovoltaic device is an effective method to improve device *** there have been many studies on donor polymer fluorination,blends containing both a fluorinated donor and fluorinated NFA have rarely been *** this study,we use two donor polymers (4'-FT-HTAZ and 4'-FT-FTAZ) and two NFAs (ITIC-Th and ITIC-Th1) with different amounts of fluorine (from 2F to 6F) to investigate how the degree of fluorination in a blend impacts device *** find that fluorinating the NFA leads to a higher short-circuit current density (Jsc) and fill factor (FF),however,the open-circuit voltage (Voc) is decreased due to a depressed lowest unoccupied {3. orbital (LUMO) *** additional fluorine to the donor polymer does not have a large effect on the Jsc or FF,but it does lead to an improved *** fluorinating the NFA and having more fluorine on the donor polymer,we obtain both a high Jsc and Voc simultaneously,leading to a power conversion efficiency over 10% in the case of 4'-FT-FTAZ:ITIC-Th1,which has the most amount of fluorine (6F).

关键词： organic solar cells non-fullerene acceptors fluorination bulk heterojunction

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卟啉衍生物及其高分子材料

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高分子学报 2018年第7期28卷 864-877页

作者：张佳玮马志远赵传壮袁金颖朱晓夏中国科学院宁波材料工程与技术研究所宁波315201 蒙特利尔大学化学系蒙特利尔H3.3.7 宁波大学材料科学与化学工程学院宁波315211 清华大学化学系北京100084

卟啉是一类由4个吡咯环通过次甲基相连而形成的共轭大环化合物.卟啉及其衍生物广泛存在于生物体内,参与催化、氧的输运和能量转移等重要生理过程.因其独特的生理功能和物理化学特性,卟啉衍生物及其高分子材料的制备和合成引起了广泛关注... 详细信息

卟啉是一类由4个吡咯环通过次甲基相连而形成的共轭大环化合物.卟啉及其衍生物广泛存在于生物体内,参与催化、氧的输运和能量转移等重要生理过程.因其独特的生理功能和物理化学特性,卟啉衍生物及其高分子材料的制备和合成引起了广泛关注.本文介绍了卟啉及其衍生物在生命系统中的功能及其合成方法,回顾了含卟啉的高分子材料和超分子组装体的设计和制备方法,总结了近年来基于卟啉的高分子和超分子功能材料的研究动态.

关键词：卟啉卟啉衍生物功能高分子

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Scalable and ultrafast epitaxial growth of single-crystal graphene wafers for electrically tunable liquid-crystal microlens arrays

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science Bulletin 2019年第10期64卷 659-668页

作者： Bing Deng Zhaowei Xin Ruiwen Xue Shishu zhang Xiaozhi Xu Jing Gao Jilin Tang Yue Qi Yani Wang Yan Zhao Luzhao Sun Huihui Wang Kaihui Liu Mark H. Rummeli Lu-Tao Weng Zhengtang Luo Lianming Tong Xinyu zhang Changsheng Xie Z{3.fan Liu Hailin Peng Center for Nanochemistry (CNC) Beijing Science and Engineering Center for Nanocarbons Beijing National Laboratory for Molecular Sciences (BNLMS) College of Chemistry and Molecular Engineering Peking University Beijing 100871 China beijing Graphene Institute (BCl) Beijing 100094 China Wuhan National Laboratory for Optoelectronics School of Automation National Key Laboratory of Science and Technology on Multispectral Information Processing Huazhong University of Science & Technology Wuhan 430074 China department of Chemical and Biological engineering Materials Characterization and Preparation Facility The Hong Kong University of Science and Technology Hong Kong 999077 China State Key Laboratory for Mesoscopic Physics School of Physics Peking University Beijing 100871 China Institute of Functional Nano and Soft Materials (FUNSOM) J iangsu Key Laboratory for Carbon-Based Functional Materials and Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices Soochow University Suzhou 215123 China Academy for Advanced Interdisciplinary Studies Peking University Beijing 100871 China Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province College of Energy Soochow Institute for Energy and Materials Innovations Soochow University Suzhou 215006 China Centre of polymer and Carbon Materials Polish Academy of Sciences Zabrze 41-819 Poland Wuhan National Laboratory for Optoelectronics Huazhong University of Science & Technology Wuhan 430074 China

The scalable growth of wafer-sized single-crystal graphene in an energy-efficient manner and compatible with wafer process is critical for the killer applications of graphene in high-performance electronics and optoelectronics. Here, ultrafast epitaxial growth of single-crystal graphene wafers is realized on singlecrystal Cu90Ni10(1 1 1) thin films fabricated by a tailored two-step magnetron sputtering and recrystallization process. The minor nickel(Ni) content greatly enhances the catalytic activity of Cu, rendering the growth of a 4 in. single-crystal monolayer graphene wafer in 10 min on Cu90Ni10(1 1 1), 50 folds faster than graphene growth on Cu(1 1 1). Through the carbon isotope labeling experiments, graphene growth on Cu90Ni10(1 1 1) is proved to be exclusively surface-reaction dominated, which is ascribed to the Cu surface enrichment in the Cu Ni alloy, as indicated by element in-depth profile. One of the best benefits of our protocol is the compatibility with wafer process and excellent scalability. A pilot-scale chemical vapor deposition(CVD) system is designed and built for the mass production of single-crystal graphene wafers, with productivity of 25 pieces in one process cycle. Furthermore, we demonstrate the application of single-crystal graphene in electrically controlled liquid-crystal microlens arrays(LCMLA), which exhibit highly tunable focal lengths near 2 mm under small driving voltages. By integration of the graphene based LCMLA and a CMOS sensor, a prototype camera is proposed that is available for simultaneous light-field and light intensity imaging. The single-crystal graphene wafers could hold great promising for highperformance electronics and optoelectronics that are compatible with wafer process.

关键词： Graphene Ultrafast growth CuNi(1 1 1)thin film Single crystal wafer Liquid crystal microlens arrays

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Carbon nanotubes assisting interchain charge transport in semiconducting polymer thin films towards much improved charge carrier mobility

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science china Materials 2019年第6期62卷 813-822页

作者： Zhe Zheng Zhenjie Ni Xiaotao zhang Yonggang Zhen Huanli Dong Jin zhang Wenping Hu Tianjin Key Laboratory of molecular Optoelectronic science Department of ChemistrySchool of ScienceTianjin University and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) beijing National Laboratory for molecular sciences Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of Sciences Center for Nanochemistry Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular Sciences (BNLMS)College of Chemistry and Molecular EngineeringPeking University

Conjugated polymers attracted much attention in the past few decades due to their wide applications in various optoelectronic devices and circuits. The charge transport process in conjugated polymers mainly occurs in the intrachain and interchain parts, where the interchain charge transport is generally slower than intrachain transport and may slow down the whole charge transport properties. Aiming at this issue, herein we employ semiconducting single-walled carbon nanotubes(s-SWNTs) as efficient charge-transporting jointing channels between conjugated polymer chains for improving the charge transport performance. Taking the typical conjugated polymer, ploy-N-alkyl-diketopyrrolopyrrole-dithienylthieno[3.2-b]thiophene(PDPP-TT) as an example, polymer thin film transistors(PTFTs) based on the optimized blended films of PDPP-TT/s-SWNTs exhibit an obviously increasing device performance compared with the devices based on pure PDPP-TT films, with the hole and electron mobility increased from 2.3. to 12.3. cm^2 V^-1 s^-1 and from 2.02 to 5.77 cm^2 V^-1 s^-1, respectively. This result suggests the importance of forming continuous conducting channels in conjugated polymer thin films, which can also be extended to other polymeric electronic and optoelectronic devices to promote their potential applications in large-area, low-cost and high performance polymeric electronic devices and circuits.

关键词： conjugated polymer s-SWNTs connected conducting channel carrier mobility

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甲壳型液晶高分子的构筑、自组装及其功能化

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高分子学报 2017年第10期27卷 1591-1608页

作者：候平平张振宇平静沈志豪范星河周其凤北京分子科学国家实验室高分子化学与物理教育部重点实验室软物质科学与工程中心北京大学化学与分子工程学院北京100871

甲壳型液晶高分子的发展很大程度上依赖于聚合物自组装的发展,而各种可设计、可预测、可调控的自组装策略的涌现,将甲壳型液晶高分子研究推向前所未有的高度,同时也极大地丰富了高分子化学与物理的内容,提升了研究水准.研究表明,侧链"... 详细信息

甲壳型液晶高分子的发展很大程度上依赖于聚合物自组装的发展,而各种可设计、可预测、可调控的自组装策略的涌现,将甲壳型液晶高分子研究推向前所未有的高度,同时也极大地丰富了高分子化学与物理的内容,提升了研究水准.研究表明,侧链"甲壳效应"在调控甲壳型液晶高分子有序结构等方面有着重要作用.本综述从甲壳型液晶高分子设计合成、液晶相态调控、嵌段共聚物自组装和功能化应用等方面,总结和评述了近年来该领域国内的最新研究进展.最后,本综述总结了甲壳型液晶高分子在发展中所面临的主要问题,并对其发展趋势进行了展望.

关键词：甲壳型液晶高分子超分子液晶相态自组装软物质

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光电高分子材料的研究进展

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高分子学报 2019年第10期50卷 988-1046页

作者：黄飞薄志山耿延候王献红王利祥马於光侯剑辉胡文平裴坚董焕丽王树李振帅志刚李永舫曹镛华南理工大学高分子光电材料与器件研究所发光材料与器件国家重点实验室广州510640 北京师范大学化学学院北京100875 天津大学材料科学与工程学院天津300072 中国科学院长春应用化学研究所高分子物理与化学国家重点实验室长春130022 中国科学院化学研究所北京分子科学国家研究中心北京100190 天津大学理学院天津市分子光电科学重点实验室天津300072 北京大学化学与分子工程学院北京100871 武汉大学化学与分子科学学院武汉430072 清华大学化学系北京100084 苏州大学材料与化学化工学部先进光电材料实验室苏州215123

光电活性共轭高分子是高分子科学的前沿研究方向.共轭高分子光电材料的研究在中国引起了学术界的广泛兴趣,中国的学者们对推动此研究领域的发展做出了重要贡献,并在新的高性能光电共轭高分子的分子设计、新型及可控聚合、性能调控以及... 详细信息

光电活性共轭高分子是高分子科学的前沿研究方向.共轭高分子光电材料的研究在中国引起了学术界的广泛兴趣,中国的学者们对推动此研究领域的发展做出了重要贡献,并在新的高性能光电共轭高分子的分子设计、新型及可控聚合、性能调控以及光电应用等方面取得了一系列重要的创新成果.本文总结和评述了中国学者在光电高分子领域的研究成果与最新进展,并展望了其未来的发展.

关键词：光电高分子共轭高分子高分子合成有机光电材料与器件理论研究

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Reversible hydrogels with tunable mechanical properties for optically controlling cell migration

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Nano Research 2018年第10期11卷 5556-5565页

作者： Xin Wu Wenmao Huang Wen-Hao Wu Bin Xue Dongfang Xiang Ying Li Meng Qin Fei Sun Wei Wang Wen-Bin zhang Yi Cao Collaborative Innovation Center of Advanced Microstructures National Laboratory of Solid State Microstructure and Department of Physics Nanjing University Nanjing 210093 China Key Laboratory of polymer chemistry & Physics of Ministry of Education Center for Soft Matter Science and Engineering College ot Chemistry and Molecular Engineering Peking University Beijing 100871 China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology School of Environmental Science and Engineering Nanjing University olin formation Science & Technology Nanjing 210044 China department of Chemical and Biomolecular engineering Division of BioMedical Engineering and Center for Systems Biology & Human Health The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong China

Synthetic hydrogels are widely used as biomimetic in vitro model systems to understand how cells respond to complex microenvironments. The mechanical properties of hydrogels are deterministic for many cellular behaviors, including cell migration, spreading, and differentiation. However, it remains a major challenge to engineer hydrogels that recapture the dynamic mechanical properties of native extracellular matrices. Here, we provide a new hydrogel platform with spatiotemporally tunable mechanical properties to assay and define cellular behaviors under light. The change in the mechanical properties of the hydrogel is effected by a photo-induced switch of the cross-linker fluorescent protein, Dronpa145N, between the tetrameric and monomeric states, which causes minimal changes to the chemical properties of the hydrogel. The mechanical properties can be rapidly and reversibly tuned for multiple cycles using visible light, as confirmed by rheological measurements and atomic force microscopy- based nano-indentation. We further demonstrated real-time and reversible modulation of cell migration behaviors on the hydrogels through photo-induced stiffness switching, with minimal invasion to the cultured cells. Hydrogels with a programmable mechanical history and a spatially defined mechanical hierarchy might serve as an ideal model system to better understand complex cellular functions.

关键词： Dronpa photo-responsive hydrogel mechanical properties cell migration artificial extracellular matrix

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Electrodes with Electrodeposited Water-excluding polymer Coating Enable High-Voltage Aqueous Supercapacitors

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Research 2020年第1期2020卷 711-723页

作者： Wujie Dong Tianquan Lin Jian Huang Yuan Wang zhichao zhang Xin Wang Xiaotao Yuan Jie Lin I-Wei Chen Fuqiang Huang State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China State Key Laboratory of Rare Earth Materials chemistry and Applications College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China department of Materials science and engineering University of PennsylvaniaPhiladelphiaPA 19104USA

Aqueous supercapacitors are powerful energy sources,but they are limited by energy density that is much lower than lithium-ion *** raising the voltage beyond the thermodynamic potential for water splitting(1.23.V)can boost the energy density,there has been much effort on water-stabilizing salvation additives such as Li_(2)SO_(4) that can provide an aqueous electrolyte capable of withstanding~1.8 *** by the first-principles calculations that reveal water can promote hydrogen and oxygen evolution reactions,here,we pursue a new strategy of covering the electrode with a dense electroplated polymerized polyacrylic acid,which is an electron insulator but a proton conductor and proton *** combined effect of salvation and coating expands the electrochemical window throughout pH 3.to pH 10 to 2.4V for both fast and slow proton-mediated redox *** allows activated carbon to quadruple the energy density,a kilogram of nitrogen-doped graphene to provide 127 Watt-hour,and both to have improved endurance because of suppression of water-mediated ***,aqueous supercapacitors can now achieve energy densities quite comparable to that of a lithium-ion battery,but at 100 times the charging/discharging speed and cycle durability.

关键词： lithium durability battery

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