室温可见光引发聚合诱导自组装制备P2VP-b-PSt纳米材料

Preparation of P2VP-b-PSt nano-objects via visible light-mediated polymerization-induced self-assembly at room temperature

针对苯乙烯(St)的常温聚合速率缓慢影响了其在常温聚合诱导自组装(PISA)中的应用问题,提出了一种无需添加光引发剂或光催化剂,以蓝光LED为光源,聚2-乙烯基吡啶(P2VP)为大分子链转移剂,常温下在甲醇中实现St的PISA的方法。通过可见光引发的PISA制备了聚2-乙烯基吡啶-b-聚苯乙烯(P2VP-b-PSt)纳米材料,考察了St/P2VP的比例、聚合时间及P2VP的链长对聚集体形貌的影响,结果表明,当P2VP的分子量为4000、St/P2VP的摩尔比从400/1变化到4000/1、聚合时间从3h变化到24h,均可以实现聚集体从球形胶束到囊泡的转变;当P2VP的分子量为8300时,仅能得到球形胶束。

The application of styrene(St)in the polymerization-induced self-assembly(PISA)at room temperature has been limited by the slow polymerization rate of St at ambient temperature.In this work,a simple PISA approach was proposed for poly(2-vinylpyridine)-block-polystyrene(P2VP-b-PSt)using blue LED as illuminant and avoiding employment of photoinitiators or photocatalysts.By using P2VP as macromolecular chain transfer agent,St as a monomer and methanol as solvent,nano-objects of poly(2-vinylpyridine)-block-polystyrene(P2VP-b-PSt)were successfully prepared at room temperature.The effects of the molar ratio of St to P2VP,polymerization time and chain length of P2VP on the aggregate morphologies were investigated.The results showed that the morphology of aggregate was transformed from spherical micelle to vesicle when the molecular weight of P2VP was 4000,the molar ratio of St/P2VP was varied from 400/1 to 4000/1 and the polymerization time was from 3h to 24h,while only spherical micelles were obtained when the molecular weight of P2VP was 8300.