中文摘要：

报导了一种新的制备不对称粒子的简单方法.首先,利用旋转涂膜法在云母片表面涂上一层聚4-乙烯基吡啶（P4VP）薄膜,并且P4VP薄膜中分散有自由基引发剂偶氮二异丁腈（AIBN）和二乙烯基苯（DVB）;然后将云母片插入溶解有N-异丙基丙烯酰胺（NIPAM）的水溶液,在氮气保护下升高温度,实施自由基聚合.聚合起始阶段,AIBN分解的自由基主要是在P4VP薄膜中引发DVB聚合.由于相分离,DVB聚合后形成的PDVB在P4VP中形成粒子.随着聚合的进行,由于PDVB粒子的不断长大或向水/P4VP界面迁移,使得粒子的一侧暴露在水相中.在界面上,PDVB粒子上的大分子自由基或AIBN新分解产生的自由基与PDVB中剩余双键继续反应形成的大分子自由基引发水相中的NIPAM反应,从而在粒子的一侧形成PNIPAM接枝;而PDVB粒子的另一侧则嵌在P4VP膜中,不会参加接枝反应.最后,实施与P4VP层分离后即可得到两亲性的PDVB-PNIPAM不对称粒子.

英文摘要：

Herein,we report a novel and facile approach to the preparation of asymmetric amphiphilic polymeric nanoparticles.Firstly,a P4VP thin film on surface of mica sheets was prepared through spin-coating.In the film,azobisisobutyronitrile （AIBN） and divinylbenzene （DVB） were solubilized.Then,the mica slides coated with the P4VP/AIBN/DVB film were immersed in an aqueous solution of N-isopropylacrylamide （NIPAM）.After heating the system to 80 ℃ in N2 atmosphere,at the early stage,free radical polymerization of DVB took place in the hydrophobic layer,which was initiated by AIBN that were mostly in the P4VP film.Due to phase separation with the P4VP matrix,the polymerization of DVB led to PDVB spheres,and the size of the PDVB spheres increased with the polymerization.When the diameter of PDVB spheres was larger than the thickness of P4VP layer or due to the migration of the PDVB spheres to water/P4VP layer interface,one side of the spheres exposed to water phase initiated the polymerization of hydrophilic monomer N-isopropylacrylamide （NIPAM）.The other side of the PDVB sphere embedded in the P4VP layer was protected.This process led to the formation of amphiphilic asymmetric particles with water-soluble grafted chains on one side of a hydrophobic sphere.