【摘要】 具有光响应性的采用乙醇相分散共聚的方法将螺吡喃基团引入聚合原位自组装体系,合成了具有光响应性的聚甲基丙烯酸N,N-二甲基氨基乙酯-b-聚(甲基丙烯酸苄酯-co-甲基丙烯酸螺吡喃酯)(PDMA-b-P(BzMA-co-SPMA))共聚物组装体.通过调节BzMA、SPMA和PDMA的投料比,制备了球形胶束、蠕虫状胶束、"章鱼"状组装体、囊泡、实心粒子等不同形貌的组装体.所得组装体分散液具备良好的紫外响应显色性:在交替的UV(紫外)/可见光照射下,组装体分散液发生无色-蓝色的可逆转变.使用光响应组装体墨水绘制的文字和图案可以实现在UV/可见光照射(或升温)下的可逆显示与隐藏.这种方法可拓展应用于文字和图案的打印,实现精细图案的大批量快速制备.二维光响应图案具备良好的稳定性,且光响应过程具备良好的可循环性.更多还原

【Abstract】 A series of spiropyrane-containing copolymer assemblies—p o ly(N,N-dimethylaminoethyl methacrylate)-b-poly{(benzyl methacrylate)-co-[1’-(2-methacryloxyethyl)-3’,3’-dimethyl-6-nitro-spiro(2 H-1-benzopyran-2,2’-indoline)]}(PDMA-b-P(BzMA-co-SPMA)) were prepared by reversible addition-fragmentation chain transfer(RAFT) polymerization-induced self-assembly(PISA), where SPMA units act as the photo-responsive moieties, P(BzMA-co-SPMA) chains as the core-forming blocks, and PDMA chains as shell-forming blocks. First,PDMA was prepared by RAFT polymerization in ethanol at 80 °C. With PDMA as macro chain transfer agent, the RAFT PISA of BzMA and SPMA in ethanol at 70 °C were completed. By changing the feed ratios of BzMA,SPMA, and PDMA, diverse morphologies, such as spheres, worms, "octopus"-like structures, vesicles, and solid particles, were readily prepared. During UV irradiation, the absorbance maximum at 585 nm increased successively, suggesting the spiropyrane structure gradually isomerized into merocyanine structure. As a result,copolymer assembly dispersion underwent a colorless-to-colorful transformation. Subsequently, the colorful copolymer assembly dispersion was exposed to visible light. The results suggested that the absorbance maximum at 585 nm gradually decreased and the colorful copolymer assembly dispersion transformed into colorless. Using the copolymer assembly dispersion as ink, the characters and patterns were drawn on papers. Since the copolymer assembly dispersion was colorless, the characters and patterns were invisible. Upon UV irradiation, with spiropyrane isomerized into merocyanine, the characters and patterns changed to blue and visible, while upon visible light irradiation or heating, merocyanine structure isomerized into spiropyrane, which induced the characters and patterns to become colorless and invisible. Taking advantage of ink-jet printing, fine-patterned patterns and two-dimensional materials could be rapidly and massively produced, which also underwent reversible invisible-to-visible transformation, upon alternative UV irradiation and visible light irradiation/heating.更多还原