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61.
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64.
The effect of pH value on the electrostatic layer-by-layer self-assembly and the photo-responsive behavior of Poly{2-[4-(4-ethoxyphenylazo)phenoxy]ethyl
acrylate-co-acrylic acid} (PEAPE) was studied. Results show that in the studied pH value range, the lower the pH value is, the higher
is the UV-vis absorbance and the larger is the thickness of the multilayer films. FTIR studies indicate that the azo polyelectrolyte
exhibits a different ionization degree in solutions with different pH values. The higher absorbance and the larger thickness
of the layer-by-layer films can be attributed to the low ionization degree and the shrinkage conformation of PEAPE in the
solution with low pH values. FTIR analysis also confirms that the driving force for layer-by-layer self-assembly of PEAPE
and PDAC is the electrostatic interaction.
__________
Translated from Acta Polymerica Sinica, 2007, 5: 440–445 [译自: 高 分子学报] 相似文献
65.
将偶氮化合物乙基橙样品置于一对正交的偏振片之间,用一束激发光照射该样品,分别测量 在激发光的不同强度和不同偏振方向下探测光的透射功率,研究样品的双折射特性.实验表 明,透射光的饱和值和稳定值与激发光强成正比,且与激发光偏振方向有关,探测光与激发 光振动方向的夹角(θ)为45°时,其值最大;若θ不太小(>10°),sin22θ 与透射光的饱和值、稳定值成线性关系.同时,利用巴俾涅补偿器对样品的双折射率差进 行了测量,分别得到了绿光激发前后的准确数值为1.11×10-3和3.57×10 -3.
关键词:
偶氮
双折射
测量 相似文献
66.
Wen Piao Satoru Tsuda Dr. Yuji Tanaka Dr. Satoshi Maeda Dr. Fengyi Liu Shodai Takahashi Yu Kushida Dr. Toru Komatsu Dr. Tasuku Ueno Dr. Takuya Terai Prof. Toru Nakazawa Prof. Masanobu Uchiyama Prof. Keiji Morokuma Prof. Tetsuo Nagano Dr. Kenjiro Hanaoka 《Angewandte Chemie (International ed. in English)》2013,52(49):13028-13032
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68.
Melanie Aubert Ronan C. Nicolas Weronika Pawelec Carl‐Eric Wilén Michael Roth Rudolf Pfaendner 《先进技术聚合物》2011,22(11):1529-1538
A number of symmetrical and unsymmetrical azoalkanes of the general formula R′?N = N?R and related azoxy, hydrazone as well as azine derivatives have been synthesized in order to assess their potential as novel flame retardants for polypropylene alone or in combination with commercially available flame retardants such as alumina trihydrate (ATH), decabromodiphenyl ether (DecaBDE) and tris(3‐bromo‐2,2‐bis(bromomethyl)‐propyl)phosphate (TBBPP). The experimental results show that in the series of different sized azocycloalkanes the flame retardant efficacy decreased in the following order: R = cyclohexyl > cyclopentyl > cyclobutyl > cyclooctanyl >> cyclododecanyl. Whereas in the series of aliphatic azoalkanes compounds the efficacy decreased in the following order: R = n‐alkyl > tert‐butyl > tert‐octyl. In addition, also some of the prepared azoxy, azine, and hydrazone derivatives provide flame retardancy to polypropylene films at already very low concentrations (0.25–1 wt%). Noteworthy is that in contrast to other halogen‐free radical generators, the azoalkanes are also very effective as flame retardants in polypropylene thick moldings. Interestingly, it was found that 4,4′‐bis(cyclohexylazocyclohexyl)‐methane) shows a strong synergistic effect with ATH. Thus, in the presence of 0.5 wt% of azoalkane the ATH loading could be reduced from 60 to 25 wt% and still UL94 V‐2 rating could be reached. Furthermore, the fire testing data reveal that azoalkanes show a synergistic effect with DecaBDE and when used in conjunction with very low loadings of TBBPP. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
69.
Kenji Kinashi Yuki Kambe Masahiro Misaki Yasuko Koshiba Kenji Ishida Yasukiyo Ueda 《Journal of polymer science. Part A, Polymer chemistry》2012,50(24):5107-5114
Three types of bi‐functionalized copolymers ( P1FAz , P2FAz , and P3FAz ) with different numbers of fluorene units and an azobenzene unit were synthesized and characterized using UV–vis and polarized absorption spectroanalysis. The trans‐cis photoisomerization was conformed under 400 nm light irradiation for all copolymers in chloroform. However, in the film state, only the trans‐cis photoisomerization occurred by mono‐fluorene attached copolymer poly[(9,9‐di‐n‐octylfluorenyl‐2,7‐diyl)‐alt‐4,4′‐azobenzene)] ( P1FAz ). Photo‐induced alignment was achieved using the P1FAz film after irradiation with linear polarized 400 nm light and subsequent annealing at 60 °C. Surface orientation of a spin‐coating film of poly(9,9‐didodecylfluorene) ( F12 ) was achieved using the photo‐induced alignment layer of the P1FAz film after annealing at 90 °C. The photo‐induced alignment layer of P1FAz has potential application to the surface orientation technique for appropriate polymers, which will be useful for the fabrication of optoelectronics devices. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献