基于苯烯的可见光引发聚合诱导自组装的研究

Study on visible light-mediated polymerization-induced self-assembly of styrene

以商用蓝光LED为光源,聚2-乙烯基吡啶(P2VP)为大分子链转移剂,未添加光引发剂或光催化剂,在常温下甲醇溶液中进行了苯乙烯(St)的光引发聚合诱导自组装(PISA)。考察了当P2VP的分子量为4000,[St]∶[P2VP]=4000∶1时,聚合时间对聚2-乙烯基吡啶嵌段聚苯乙烯(P2VP-b-PSt)纳米粒形貌的影响。结果表明St在甲醇中聚合3到6 h,得到球形胶束,聚合9 h,出现蠕虫状胶束,聚合12 h部分胶束融合成囊泡,聚合24 h全部生成囊泡。光引发PISA可以通过光源的“开/关”启动和终止反应。

Visible light-mediated polymerization-induced self-assembly(PISA)was carried out at room temperature without photoinitiators or photocatalysts.It was conducted by using poly(2-vinylpyridine)(P2VP)as macromolecular chain transfer agent,styrene(St)as a monomer,and methanol as solvent.The effect of polymerization time on the morphology of poly(2-vinylpyridine)-b-poly(styrene)(P2VP-b-PSt)nano-objects was investigated when the molecular weight of P2VP was 4000 and the molar ratio of St and P2VP was 4000∶1.As a result,spherical micelles were obtained when the polymerization time was from 3 to 6 h,wormlike micelles were obtained when the polymerization time was 9 h,part of the morphology of nano-objects was transformed from spherical micelle to vesicle when the polymerization time was 12 h,and vesicles were gained when the polymerization time was 24 h.And the visible light-mediated PISA can be initiated and terminated by“ON/OFF”switch of the light source.