双亲性聚(丙烯酸-co-苯乙烯)的制备及其自组装行为

在二氧六环介质中,通过自由基溶液共聚,合成了一系列组成不同的双亲性无规共聚物聚(丙烯酸-co-苯乙烯)(P(AA-co-St)),用核磁共振、凝胶渗透色谱和示差扫描量热等方法对P(AA-co-St)的结构参数进行了表征。在选择性溶剂(二氧六环/水)中,对一系列组成不同的P(AA-co-St)进行自组装,制得粒径不同的P(AA-co-St)胶束。用紫外可见光分光光度计、激光光散射仪、扫描电子显微镜等研究了P(AA-co-St)在水溶液中的胶束化行为。实验结果表明,P(AA-co-St)在选择性溶剂(二氧六环/水)中可实现自组装,形成规则球状胶束。P(AA-co-St)中AA的含量及胶束化条件的改变对P(AA-co-St)胶束的形成、胶束流体动力学半径(Rh)和临界聚集水含量(CWC)均有影响。CWC随AA含量的增加而增大;当x(AA)<44.8%时,Rh随AA含量的增加而减小;当x(AA)>44.8%时,Rh随AA含量的增加而增大;缓冲溶液的pH从4增加到10时,Rh从170nm减至50nm。

Synthesis and Self-Assembling of Amphiphilic Poly(Acrylic Acid-CO-Styrene)

A series of amphiphilic random copolymers poly(acrylic acid-co-styrene)(P(AAco-St)) were synthesized by free radical copolymerization in dioxane medium.The copolymers were characterized by means of 1H NMR,GPC and DSC.The self-assembling of P(AA-co-St)s with different compositions was carried out in selective solvent dioxane/H2O to obtain micelles with different particle radiuses.The micellization of P(AA-co-St) was studied by means of DLS and SEM,which showed that P(AA-co-St) can be self-assembled into regular sphere micelles.AA content in P(AA-co-St) and condition of micellization affect critical water content(CWC),formation of micelles and hydrokinetic radiuses(Rh) of micelles.CWC of P(AA-co-St) solution rises with increase of AA content.When x(AA)<44.8%,Rh of P(AA-co-St) micelles reduces with increase of AA content.When x(AA)>44.8%,Rh goes synchronously with increase of AA content.When pH of buffer solution changes from 4 to 10,Rh of P(AA-co-St) micelles reduces from 170 nm to 50 nm.