Effect of stabilizer on formation of "onionlike" multilayered polystyrene-block-poly(methyl methacrylate) particles.
Effect of stabilizer on formation of "onionlike" multilayered polystyrene-block-poly(methyl methacrylate) particles.
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DOI：
10.1021/la063654f
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发表时间：
2007-04
期刊：
影响因子：
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通讯作者：
Naohiko Saito;R. Takekoh;Reiko Nakatsuru;M. Okubo
中科院分区：
文献类型：
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作者：
Naohiko Saito;R. Takekoh;Reiko Nakatsuru;M. Okubo
研究了不同稳定剂对聚甲基丙烯酸甲酯(PS-b-PMMA)“洋葱状”多层聚苯乙烯嵌段共聚物(PS-b-PMMA)粒子形成的影响。分散在水介质中的PS-b-PMMA/甲苯微滴中甲苯的释放导致了所用稳定剂粒子中洋葱状多层结构的形成。然而，稳定剂的种类对粒子的表面组成有很大的影响。当使用十二烷基硫酸钠(SDS)和聚乙烯醇(PVA)作为稳定剂时，PMMA相占据了粒子的表面。另一方面，在Emulgen 911(聚氧乙烯壬基苯基醚)和Tween80(聚氧乙烯山梨醇单油酸酯)作为稳定剂的情况下，PS相占据了表面。SDS、PVA和Emulgen 911的结果与PS-b-PMMA粒子被聚合物相占据的表面层相一致，从而使界面张力低于另一相。然而，在吐温80的情况下，聚合物的水和甲苯溶液之间的界面张力显示出几乎相同的值，因此无法预测表面聚合物相。
The effect of the kind of stabilizers on the formation of "onionlike" multilayered polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) particles was studied. The release of toluene from PS-b-PMMA/toluene droplets dispersed in aqueous medium resulted in the formation of onionlike multilayered structures in the particles for all stabilizers used. However, the surface composition of the particles was strongly affected by the kind of stabilizer. When sodium dodecyl sulfate (SDS) and poly(vinyl alcohol) (PVA) were used as stabilizers, the surface of the particles was occupied by PMMA phase. On the other hand, in the cases of Emulgen 911 (polyoxyethylene nonylphenyl ether) and Tween 80 (polyoxyethylene sorbitan monooleate) as stabilizers, the PS phase occupied the surfaces. These results for SDS, PVA, and Emulgen 911 are consistent with the surface layer of the PS-b-PMMA particles being occupied by the polymer phase, which gives a lower interfacial tension than that of another phase. However, in the case of Tween 80, interfacial tensions between water and toluene solutions of the polymer showed almost the same values making it impossible to predict the surface polymer phase.