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Fabrication of Photochromic films by Electrolytic and Oxidation Polymerization

电解聚合和氧化聚合制备光致变色薄膜

基本信息

批准号：
12640567
负责人：
UCHIDA Kingo
金额：
$ 2.3万
依托单位：
RYUKOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

Photochromic molecules attract much attention from both fundamental as well as practical points of view because of their potential for applications to optical devices such as optical memories and switches, Among the photochromic compounds, diarylethenes are regarded as the best candidate, because of the thermal stability of their both isomers and the fatigue resistant property. For the fabrication of thin photochrbmic films for the applications, various methods have been employed. Dispersing the photochromic molecules into polymer matrices is the most convenient method to prepare the photochromic films. Although increment of the dye concentration is strongly desired to enhance the photochromic efficiency, preparation of films containing high concentration of the dyes is not easy because segregation takes place to some, extent after long term storage. Bulk amorphous and crystalline photochromic films have been extensively studied for the purpose. We now propose a new method to form thin … More films by oxidation polymerization.A diarylethene derivative 1,2-bis[2,4-dimethyl-5-(o-hydroxy-phenyl)-3-thienyl]-hexafluorocyclopentene (1a) was synthesized from commercially available 2,4-dibromo-3,5-dimethylthiophene. The isomer 1,2-bis[2,4-dimethyl-5-(m-hydroxyphenyl)-3-thienyl]-hexafiuorbcyclopentene (2a) was also synthesized by similar method. Upon UV light (280 nm) irradiation, the solution of la turned to red and absorption bands appeared at 545 and 347 nm attributable to the closed-ring isomer 1b, and the peak of 1a at 254 nm was suppressed. Upon visible light irradiation, the red color was bleached and regenerated the open-ring isomer la. The quantum yields of cyclization and cycloreversion of 1 were 0.19 (measured by 280 nm light irradiation) and 0.03 (measured by 492 nm light irradiation), respectively.The diarylethene 1a was polymerized according to Hay's method The prepared polymer film p(1a) showed a reversible photochromic reaction by alternate irradiation with UV and visible light. X-ray diffraction measurement showed no peaks even after 1 year storage at room temperature. This indicates that the polymer film is in the amorphous phase. The new amorphous photochromic film will be applicable for wave-guide and novel recording media. Less

光致变色化合物因其在光存储器、光开关等光学器件中的应用前景而受到人们的广泛关注。在光致变色化合物中，二芳基乙烯类化合物因其两种异构体的热稳定性和抗疲劳性能而被认为是最佳的候选者。为了制造用于这些应用的光致变色薄膜，已经采用了各种方法。将光致变色分子分散到聚合物基体中是制备光致变色薄膜最方便的方法。虽然强烈希望染料浓度的增加以提高光致变色效率，但是制备含有高浓度染料的膜并不容易，因为在长期储存后会发生一定程度的分离。为此目的，已经广泛地研究了块状非晶和结晶光致变色膜。我们现在提出一种新的方法， ...更多信息从市售的2，4-二溴-3，5-二甲基噻吩合成了二芳基乙烯衍生物1，2-双[2，4-二甲基-5-（邻羟基苯基）-3-噻吩基]-六氟环戊烯（1a）。用同样的方法合成了1，2-双[2，4-二甲基-5-（间羟基苯基）-3-噻吩基]六氟环戊烯（2a）。在紫外光（280 nm）照射下，la的溶液变成红色，并且在545和347 nm处出现归因于闭环异构体1b的吸收带，并且1a在254 nm处的峰被抑制。在可见光照射下，红色被漂白并再生开环异构体Ia。1的环化和环化逆转的量子产率分别为0.19（280 nm光照射测定）和0.03（492 nm光照射测定）.二芳基乙烯1a按Hay方法聚合，所得聚合物膜p（1a）在紫外光和可见光交替照射下表现出可逆的光致变色反应. X射线衍射测量显示即使在室温下储存1年后也没有峰。这表明聚合物膜处于非晶相。这种新型的非晶态光致变色薄膜在光波导和新型记录介质方面具有重要的应用前景。少