Novel photoactive hyperbranched poly(aryl ether)s containing azobenzene chromophores for optical storage
作者:Xingbo Chen、Yunhe Zhang、Baijun Liu、Jingjing Zhang、Hui Wang、Wenyi Zhang、Qidai Chen、Songhao Pei、Zhenhua Jiang
DOI:10.1039/b807956k
日期:——
Two novel hyperbranched poly (aryl ether)s with azobenzene moieties in both the main chain and side chain of the branched arms were prepared by using B3 + A2 methodology via a nucleophilic aromatic substitution polycondensation. Structures of the hyperbranched poly (aryl ether)s with azobenzene moieties (azo-HPAEs) were characterized by means of IR, UV-visible, 1H NMR spectroscopy, and XRD. It is shown that both the azo-HPAEs exhibit high glass transition temperatures (Tg), excellent thermal stability and homogeneous photochromic behavior. By exposing their spin-coating films to an interference pattern of laser beam, both the azo-HPAEs could be used for rapid (within 30 s) fabrication of surface-relief gratings (SRGs). The obtained SRGs present no shape changes even at temperatures up to 200 °C. Especially, the azo-HPAE with azobenzene moieties in the side chain shows larger photoinduced birefringence intensity and better reversible optical storage than the one with azobenzene moieties in the main chain upon irradiation with 532 nm Nd:YAG laser. The novel azo-PAEs are photoactive to UV light (355 nm), making them potentially useful for high density information storage.
采用B3+A2方法通过亲核芳香取代缩聚反应制备了两种新型超支化聚芳醚,其支链的主链和侧链均具有偶氮苯部分。具有偶氮苯部分的超支化聚芳醚(azo-HPAEs)的结构通过红外、紫外-可见、1H NMR 光谱和 XRD 进行了表征。结果表明,两种偶氮-HPAE 均表现出高玻璃化转变温度 (Tg)、优异的热稳定性和均匀的光致变色行为。通过将旋涂薄膜暴露在激光束的干涉图案下,这两种偶氮 HPAE 都可以用于快速(30 秒内)制造表面浮雕光栅(SRG)。即使在高达 200 °C 的温度下,所获得的 SRG 也不会出现形状变化。特别是,在532 nm Nd:YAG激光照射下,侧链具有偶氮苯部分的azo-HPAE比主链具有偶氮苯部分的azo-HPAE表现出更大的光致双折射强度和更好的可逆光存储。新型偶氮 PAE 对紫外光(355 nm)具有光敏性,这使得它们可用于高密度信息存储。