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72.
Jiarui Yu Nan Gao Xiaowen Xie Xing Xin Zhanqi Li Shuai Chen Jingkun Xu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(5):794-802
Thermally healing capability of cracks and defects is important and urgent for the safe operation and life extending of electric materials and devices. Here, by the combination of thermally driven reversible Diels–Alder (DA) interaction and in-situ chemical oxidative polymerization of 3,4-ethylenedioxythiophene (EDOT), a series of intrinsically conductive poly(3,4-ethylenedioxythiophene) (PEDOT)/DA composites possess intrinsically self-healing property under low-temperature (reverse DA reaction at 100°C; DA crosslinking at 60°C) stimulus were achieved. The crosslinking DA bonding reactions are multiple from the co-existence of pre-synthesized macromolecular polyurethane attached DA units (PU-DA) and 2,4-hexadiyne-1,6-diol (DADOL) in the films. PU-DA involved in the polymerization process of EDOT to endow PEDOT with outstanding solution-processability, uniform film making, and structural self-healing capability, while DADOL was added to enhance the cross bonding between polymer chains. This work will accelerate the research and application development of intrinsically self-healing conducting polymers for commercial capacitors, antistatic coatings, implantable, printable electronics, and so on. 相似文献
73.
以"应用广泛的酸、碱、盐"教学为例,从微观层面利用微粒观,帮助学生突破学习的难点,运用微粒观建构概念,理解化学反应的本质,把握物质的通性,合理运用。 相似文献
74.
Dr. Malin Li Dr. Yu Gao Dr. Nan Chen Dr. Xing Meng Prof. Chunzhong Wang Dr. Yaoqing Zhang Dr. Dong Zhang Prof. Yingjin Wei Dr. Fei Du Prof. Gang Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11405-11412
Cu3V2O8 nanoparticles with particle sizes of 40–50 nm have been prepared by the co‐precipitation method. The Cu3V2O8 electrode delivers a discharge capacity of 462 mA h g?1 for the first 10 cycles and then the specific capacity, surprisingly, increases to 773 mA h g?1 after 50 cycles, possibly as a result of extra lithium interfacial storage through the reversible formation/decomposition of a solid electrolyte interface (SEI) film. In addition, the electrode shows good rate capability with discharge capacities of 218 mA h g?1 under current densities of 1000 mA g?1. Moreover, the lithium storage mechanism for Cu3V2O8 nanoparticles is explained on the basis of ex situ X‐ray diffraction data and high‐resolution transmission electron microscopy analyses at different charge/discharge depths. It was evidenced that Cu3V2O8 decomposes into copper metal and Li3VO4 on being initially discharged to 0.01 V, and the Li3VO4 is then likely to act as the host for lithium ions in subsequent cycles by means of the intercalation mechanism. Such an “in situ” compositing phenomenon during the electrochemical processes is novel and provides a very useful insight into the design of new anode materials for application in lithium‐ion batteries. 相似文献
75.
Effect of chain architecture on the phase transition of star and cyclic poly(N‐isopropylacrylamide) in water 下载免费PDF全文
Na Xue Xing‐Ping Qiu Yougen Chen Toshifumi Satoh Toyoji Kakuchi Françoise M. Winnik 《Journal of Polymer Science.Polymer Physics》2016,54(20):2059-2068
The heat‐induced phase transition of aqueous solutions of Poly(N‐isopropylacrylamide) (PNIPAM) in water is examined for a four‐arm PNIPAM star (s‐PNIPAM), a cyclic PNIPAM (c‐PNIPAM), and their linear counterparts (l‐PNIPAM) in the case of polymers (1.0 g L?1) of 12,700 g mol?1 < Mn < 14,700 g mol?1. Investigations by turbidity, high‐sensitivity differential scanning calorimetry (HS‐DSC), and light scattering (LS) indicate that the polymer architecture has a strong effect on the cloud point (Tc: decrease for s‐PNIPAM; increase for c‐PNIPAM), the phase transition enthalpy change (ΔH decrease for s‐PNIPAM and c‐PNIPAM), and the hydrodynamic radius of the aggregates formed above Tc (RH: c‐PNIPAM < s‐PNIPAM < l‐PNIPAM). The properties of s‐PNIPAM are compared with those of previously reported PNIPAM star polymers (3 to 52 arms). The overall observations are described in terms of the arm molecular weight and the local chain density in the vicinity of the core of the star, by analogy with the model developed for PNIPAM brushes on nanoparticles or planar surfaces. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2059–2068. 相似文献
76.
77.
Au/H相似性的研究是现代化学中的一个热门话题.我们从理论上报道Au/H相似的新成员:共价化合物B2Au4,离子化合物Al2Au4和BAl Au4.采用密度泛函和波函数理论方法对比研究了缺电子体系B2Au4、Al2Au4和BAl Au4的几何和电子结构.详细讨论了它们基态结构的轨道、适应性自然密度划分(Ad NDP)和电子局域函数(ELF)分析.计算结果表明稍微扭曲变形的C2B2Au4是基态结构,在这个共价化合物中含有两个B―Au―B三中心二电子(3c-2e)键.然而C3vAl+(Al Au4)-和C3vAl+(BAu4)-被研究证明是含有三个X―Au―Al三中心二电子键的类盐化合物(在Al2Au4中X=Al,BAl Au4中X=B).Al2Au4和BAl Au4是至今为止首例报道的在离子缺电子体系中含有金桥键的化合物.同时计算了B2Au4-、Al2Au4-和BAl Au4-阴离子基态结构的绝热剥离能和垂直剥离能,为实验表征提供依据.文中报道的金桥键为共价键和离子键相结合的缺电子体系提供了一个有趣的键合模式,有助于设计含有高度分散金原子的新材料和催化剂. 相似文献
78.
79.
Dr. Yun‐Peng Xie Dr. Jun‐Ling Jin Prof. Xing Lu Prof. Thomas C. W. Mak 《Angewandte Chemie (International ed. in English)》2015,54(50):15176-15180
The n‐butylphosphonate ligand has been employed to construct three new silver(I) thiolate compounds. Single‐crystal X‐ray analysis revealed that complexes 1 and 2 are Ag48 and Ag51 coordination chain polymers, while 3 contains a discrete Ag48 cluster, in which three different kinds of silver(I) thiolate cluster shells enclose three different phosphonate‐functionalized silver(I) cluster cores, respectively. The structures of clusters in 1 – 3 feature three three‐shell arrangements, S@Ag12@(nBuPO3)9@Ag36S23, S@Ag11@(nBuPO3)7(MoO4)2 @Ag40S27 and MoO4@Ag12@(nBuPO3)8S6 @Ag36S24, respectively. 相似文献
80.
Tianrong Yu Yang Gao Bo Wang Xing Dai Wanrun Jiang Ruixia Song Prof. Zhanwen Zhang Prof. Mingxing Jin Prof. Yongjian Tang Prof. Zhigang Wang 《Chemphyschem》2015,16(15):3308-3312
The mechanism of depolymerization is one of the most essential issues in chemical engineering and materials science. In this work, we investigate the depolymerization reactions of three typical free‐radical poly(alpha‐methylstyrene) tetramers by using first‐principles density functional theory. The calculated results show that these reactions all need to overcome the energy barriers in the range of 0.58 to 0.77 eV, and that breaking the C?C bond at the chain end leads to the dissociation of alpha‐methylstyrene monomers from the polymers. Electronic‐structure analysis indicates that the reactions occur easily at the CR3 unsaturated end, and that the frontier molecular orbitals that participate in the reactions are mainly localized at the unsaturated ends. Meanwhile, spin population analysis presents the unique net spin‐transfer process in free‐radical depolymerization reactions. We hope the current findings can contribute to understanding the free‐radical depolymerization mechanism and help guide future experiments. 相似文献