Oligo(aromatic ether sulfone)-F as a Nonlinear Polarized Polymeric Material: an Experiment and DFT Study

Polymeric membranes with diverse structures have attracted much attention as new materials for nonlinear optical devices. In this report, a novel oligomer of poly(aromatic ether sulfone)(OAES) has been synthesized and characterized. The electronic structure as well as linear and nonlinear optical properties has been studied by density function theory. The effect for general nonlinear optical polarizability of various condition has been further researched such as absence of side chains and introduction of phenyl substituent on side chains. The static and frequency-dependent hyperpolarizabilities of OAES and its derivatives have been calculated. This work interprets an efficient adjustment for the frequency response and the intensity of nonlinear optical polarizability can be achieved by regulating the structure of system, which provides a new potential for the application of oligomeric materials on nonlinear optical field.     

高性能磺化聚(苯-酰亚胺)质子传输膜的合成及表征

本文首次利用Ni11催化偶联合成了一系列的磺化聚苯和聚(苯-酰亚胺)质子传输膜材料,在聚合物中引入酰亚胺基团,提高了聚合物的成膜性和机械性能.由于SPI(Ⅰ)和SPI(Ⅱ)中存在不对称结构的酰亚胺基团,破坏了分子链的堆积,因此得到的膜具有较高的水吸收;尽管SPP具有高的IEC值,但水吸收很低.和Nafion 117(1.7?10-1S/cm,at 80℃)膜相比,磺酸的强酸性和良好的相分离结构导致高的质子导电率(大于2.6?10-1S/cm,at 80℃);尤其是在高温时,SPI(Ⅰ)和SPI(Ⅱ)膜都表现出了很高的质子导电率,可能是由于酰亚胺的不对成结构使得膜在高温时仍能保持大量的水分子以利于质子传输,例如SPI(Ⅰ)-70在80℃的质子导电率为0.687S/cm,相当于相同测试条件下Nafion 117的三倍.同时,-CF3和全芳香结构的引入大大的提高了膜的氧化稳定性,SPI(Ⅰ)膜在Fenton's试剂中完全溶解的时间高达263h;疏水的-CF3基团引入在氨基的邻位,阻止了水分进攻酰亚胺环,因此膜的水解稳定性得到很大的提高.柔性链的引入以及酐的低电子云密度,更大程度的提高了膜的水解稳定性,SPI(Ⅱ)-70在140℃的水中250h仍能保持原有的机械性能,这是目前报道的水解稳定时间最长的膜材料.因此,该膜有望成为一种新型的性能优良的质子传输膜材料在燃料电池中应用.     

Structure and Performance of Fe-N_x-C Catalyst for Oxygen Reduction Reaction Prepared by Vacuum Casting Method and the Second Pyrolysis

Affordable non-precious metal(NPM) catalysts played a vital role in the wide application of polymer electrolyte membrane fuel cells(PEMFC). In current work, a facile vacuum casting reacting method based on vacuum casting was introduced to prepare Fe-N_x-C oxygen reduction reaction(ORR) catalysts with high efficient in acid medium. The catalysts were prepared with ammonium ferrous sulfate hexahydrate(AFS) and 1,10-phenanthroline monohydrate utilizing homemade mesoporous silica template. The heat treatment and its influence on structure and performance were systematically evaluated to achieve superior ORR performance and some clues were found. And 850 ℃ was found to be the best temperature for the first and second pyrolysis. The linear sweep voltammetry(LSV) results showed that there were only 18 mV slightly negative shifts of half-wave potential(E_(1/2)) of the optimal catalyst(749 mV) compared with the commercial Pt/C(20 μg·Pt·cm~(-2)). Besides, I850 R also showed better electrochemical stability and methanol-tolerance than that of Pt/C. All evidences proved that our vacuum casting reacting strategy and heat treatment process were prospective for the future RD of high performance Fe-N_x-C ORR catalysts.     

高性能磺化聚（苯-酰亚胺）质子传输膜的合成及表征

本文首次利用Ni^11催化偶联合成了一系列的磺化聚苯和聚（苯-酰亚胺）质子传输膜材料，在聚合物中引入酰亚胺基团，提高了聚合物的成膜性和机械性能。由于SPI（I）和SPI（II）中存在不对称结构的酰亚胺基团，破坏了分子链的堆积，因此得到的膜具有较高的水吸收；尽管SPP具有高的IEC值，但水吸收很低。和Nafion 117（1．7？10^-1 S／cm，at 80℃）膜相比，磺酸的强酸性和良好的相分离结构导致高的质子导电率（大于2．6？10^-1 S／cm，at 80℃）；尤其是在高温时，SPI（I）和SPI（II）膜都表现出了很高的质子导电率，可能是由于酰亚胺的不对成结构使得膜在高温时仍能保持大量的水分子以利于质子传输，例如SPI（I）-70在80℃的质子导电率为0．687S／cm，相当于相同测试条件下Nafion 117的三倍。同时，-CF3和全芳香结构的引入大大的提高了膜的氧化稳定性，SPI（I）膜在Fenton’s试剂中完全溶解的时间高达263h；疏水的-CF3基团引入在氨基的邻位，阻止了水分子进攻酰亚胺环，因此膜的水解稳定性得到很大的提高。柔性链的引入以及酐的低电子云密度，更大程度的提高了膜的水解稳定性，SPI（II）-70在140℃的水中250h仍能保持原有的机械性能，这是目前报道的水解稳定时间最长的膜材料。因此，该膜有望成为一种新型的性能优良的质子传输膜材料在燃料电池中应用。     

咔唑及其衍生物在蓝光OLED中的应用

咔唑及其衍生物因其特有的电学性能、电化学性能和光物理性能而被广泛研究。由于这类材料不仅可以作为良好的空穴传输材料,而且在咔唑化合物的不同位置引入电子传输修饰基团,可以使得电子和空穴更加易于注入,并且可以很好地调节两者的平衡,因此,咔唑及其衍生物被认为是一类重要的蓝光荧光材料。咔唑及其衍生物不仅可以以小分子形式应用到蓝光荧光材料、蓝光磷光材料和热致延迟荧光材料,同样可以以高分子形式应用到蓝光荧光材料中。近年来,关于咔唑及其衍生物发光材料的合成及应用成为蓝光OLED研究的热点。本文综述了近年来国内外小分子咔唑及其衍生物作为蓝光有机电致发光主体材料的研究状况,对其分子结构设计光、电子轨道结构、物理性质、热学性质、电化学性质及器件性能等方面作了详细归纳比较,同时归纳了含咔唑结构的聚合物蓝光有机电致发光材料的研究进展,最后展望了咔唑基蓝光有机电致发光主体材料的发展前景和趋势。从光电转换效率及价格方面来说,热致延迟荧光材料和聚合物(含咔唑类基团)发光材料是最具有前景的蓝光OLED材料。