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采用示差扫描量热法(DSC)、一维(1D)、二维(2D)广角X-射线衍射(WAXD)和偏光显微镜(PLM)等研究手段对聚{11-[(4′-正庚氧基-4-联苯基)羰基]氧-1-十一炔}(PA-9,7)的本体相转变和相结构进行研究,并采用分子动力学方法对相结构进行模拟.结果表明,样品的相转变为近晶B相(SmB)近晶A相(SmA)各向同性态(Iso).在近晶B相中,侧链在层状结构中排列成具有六次对称性的准长程有序结构。 相似文献
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You Wu Jinlian Hu Huahua Huang Jie Li Yong Zhu Benzhong Tang Jianping Han Liangbin Li 《Journal of Polymer Science.Polymer Physics》2014,52(2):104-110
This article reports a chromic polymer, which is responsive to its shape memory properties and has both the behavior of shape memory polymers and chromic materials. We employed a strategy to fabricate such a smart material, which represents a new principle for making chromic materials. This material is made of shape memory polyurethane with tetraphenylethylene units (0.1 wt %) covalently connected to the soft‐segments (PCL, Mw = 4000). The material displays biocompatibility, shape fixity of 88–93%, and almost 100% shape recovery and has reversible mechanochromic, solvatochromic, and thermochromic shape memory effect. The memory chromism represented by the reversible change of emission intensity shows negative correlation with shape fixity, temperature, and existence of solvent. It may be explained that when the soft segments are molten or dissolved in solvent, the shape recovery switch is open, the AIE units are free from crystal binding and can migrate easily to larger areas, thus the AIE units/particles are far apart from each other and the barrier for rotation of phenyl groups is reduced, which lead to the reduction of emission intensity, appeared by no colors or pale colors, and vice versa. Since the switch is a fundamental structural character of SMPs, the shape memory properties have led to the chromism and we call this memory chromic. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014 , 52, 104–110 相似文献
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合成了带树枝状聚苯甲醚修饰基团的苯乙炔单体,在Rh[(nbd)Cl2]2催化剂的作用下得到了侧链带聚苯甲醚树枝的新型聚苯乙炔衍生物,用红外吸收光谱、核磁共振谱、紫外可见吸收光谱和凝胶渗透色谱表征了聚合物的结构.发现聚合物的重均分子量达到了57300,在氯仿、N,N-二甲基甲酰胺、四氢呋喃等有机溶剂中有良好的溶解性能.由于侧链上聚苯甲醚树枝体积庞大,聚合物主链采取立构规整的顺-顺式构象,紫外可见吸收光谱在440nm附近出现了显著的共轭主链的吸收肩峰;立构规整的顺-顺式构象使树枝状侧链形成了对主链保护的"夹套效应",聚合物热分解温度从聚苯乙炔母体的225℃提高到295℃. 相似文献
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Ting Zhu Longfeng Jiang Ying Li Zengqi Xie Zijie Li Lei Lv Hao Chen Zhiyuan Zhao Lang Jiang Benzhong Tang Hui Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(15):5098-5102
A goal for human society is to convert organic waste into valuable materials. Herein, 2‐(methylthio)‐bezothiazole (MTBT), an important organic waste in urban runoff, was catalytically converted into a series of organic semiconductors through carbon–sulfur bond activation. The efficient conversion of various substrates with different aromatic moieties and reacting functional groups (tin and boron) proved the generality of this novel diarylation Liebeskind–Srogl methodology. Moreover, the resulting organic semiconductors showed excellent performance in field effect transistors and cell imaging. This contribution presents an excellent example of converting organic waste into valuable materials and may open a new avenue to utilizing widely available aromatic thioethers. 相似文献
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基于离子相互作用,实现了以聚苯胺(PANI)为聚阳离子,以聚(邻氨基苯甲酸)(PCAN)、聚(邻氨基苯磺酸)(PSAN)为聚阴离子的层-层自组装,形成层厚均匀的全共轭超薄功能膜.由于磺酸基—SO3-的电负性高于—COO-,使得PANI-PSAN自组装膜沉积量小于PANI-PCAN;电化学实验结果显示,由于PCAN和PSAN的导电性均弱于PANI,所以两种自组装膜的电化学性能取决于PANI,但同时受到羧酸、磺酸基团的较大影响,使得PANI-PCAN自组装膜的电化学性能要优于PANI-PSAN. 相似文献
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Chen Songyan Liu Baolin Wang Benzhong Huang Meichun Chen Longhai Chen Chao 《Journal of Crystal Growth》1997,170(1-4):433-437
Lattice-mismatched heteroepitaxy has attracted considerable attention in recent years. A great interest of these systems is the possibility of integrating devices from different materials on a single substrate. 1.3 and 1.5 μm InGaAs(P)/InP laser diodes are essential for optical communication, whereas InP field effect transistor technology is less developed than that of GaAs MESFET. The performances of laser diodes are much more sensitive to a high density of disclocations, so it would be interesting to grow GaAs MESFET on InP for integration with 1.3 and 1.5 μm lasers. Due to the large difference of the thermal expansion coefficient and lattice parameter between GaAs and InP, it is very difficult to grow GaAs epilayers of high quality on it is very difficult to grow of GaAs epilayer high quality on InP substrates due to the large difference of the thermal expansion coefficient and lattice parameter between GaAs and InP. A new method, metalorganic source modulation epitaxy (MOSME), which improves the crystal quality of GaAs epilayers on InP substrates by MOVPE, has been adopted in our laboratory. The lowest full width at half maximum (FWHM) of the double crystal X-ray (DCX) diffraction spectra reaches as low as 120 arcsec for a 5 μm thick layer. Structural properties (misorientation, lattice parameters and crystal quality) of 1.0–5.0 μm thick GaAs layers grown on InP have been measured by DCX diffraction. On GaAs MESFETs grown on InP, we have measured gm = 100 ms/mm. For these transitions, the current gain cut-off frequency (Ft) is around 12 GHz and the maximum frequency of oscillation (Fmax) is higher than 30 GHz. 相似文献