Amphiphilic azo polymers: Molecular engineering, self-assembly and photoresponsive properties
Amphiphilic azo polymers: Molecular engineering, self-assembly and photoresponsive properties
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DOI：
10.1016/j.progpolymsci.2012.07.003
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发表时间：
2013-02
影响因子：
27.1
通讯作者：
Dongrui Wang;Xiaogong Wang
中科院分区：
文献类型：
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作者：
Dongrui Wang;Xiaogong Wang
两亲性聚合物具有在适当条件下形成各种自组装结构的特性。两亲性偶氮聚合物是指在两亲性聚合物中引入芳香族偶氮基团，使其具有联合收割机的自组装特性和丰富的光响应特性。近年来，通过不同的分子设计策略和合成路线，人们开发了多种两亲性偶氮聚合物。本文综述了这一迅速发展的研究领域的背景、最新进展、当前的研究方法和展望。重点介绍了两亲性偶氮聚合物的合成、自组装和光响应性能。根据分子结构，两亲性偶氮聚合物可分为均聚物、无规共聚物、嵌段共聚物、星形和树枝状聚合物。聚合物在表面或界面、溶液或分散介质中以及在固体薄膜中通过相分离显示出强烈的形成有序结构的倾向。通过垂直沉积法和溶剂诱导结构反转法可以得到两亲性偶氮聚合物的胶体阵列和多孔薄膜。两亲性偶氮聚合物及其自组装结构表现出由偶氮发色团的顺反光致异构化引发的多种光响应性质。本文详细介绍了光照射引起的表面润湿性变化、表面浮雕光栅形成、畴取向、胶体变形、胶束解离、囊泡破裂和融合等有趣的变化。这些性质在诸如光学器件、传感器和药物递送等领域的应用是有希望的。
Amphiphilic polymers are well known for their characteristics to form various self-assembling structures under proper conditions. Amphiphilic azo polymers, which are amphiphilic polymers functionalized with aromatic azo moieties, can combine wealthy photoresponsive properties with the self-assembling feature. In recent years, a wide variety of amphiphilic azo polymers have been developed through different molecular design strategies and synthetic routes. This article reviews the background, recent development, current approaches, and outlook of this rapidly developing research area. The emphasis is placed on the synthesis, self-assembly, and photoresponsive properties of amphiphilic azo polymers. According to the molecular architecture, the amphiphilic azo polymers are classified as homopolymers, random copolymers, block copolymers, star-like and dendritic polymers. The polymers show strong tendency to form well-organized structures at surfaces or interfaces, in solutions or dispersion mediums, and through phase-separation in solid thin-films. Colloidal arrays and porous thin films of amphiphilic azo polymers can be obtained through the vertical deposition method and solvent-induced structure inversion. The amphiphilic azo polymers and their self-assembled structures exhibit a variety of photoresponsive properties triggered by the trans–cis photoisomerization of azo chromophores. Some interesting variations caused by the light irradiation, such as the surface wettability change, surface-relief-grating formation, domain orientation, colloid deformation, micelle dissociation, vesicle bursting and fusion, are described in this review in detail. Such properties are promising for applications in areas such as optical devices, sensors, and drug delivery.