The influence of stirring rate on nanoparticle morphology in aqueous RAFT emulsion PISA has been investigated using the macroRAFT agents poly(poly(ethylene)glycol methyl ether acrylate)-TTC and poly(poly(ethylene glycol) methyl ether methacrylate)-TTC chain extended with styrene/n-butyl acrylate (copolymer) and methyl methacrylate (MMA), respectively. The influence of temperature was first investigated by conducting polymerizations at 50 °C and 70 °C for the MMA system, revealing that formation of high-order morphologies is facilitated at 70 °C. The influence of stirring rate was explored for both systems, showing that the extent of influence depends on the polymerization temperature. At 50 °C, high-order morphologies were obtained only at moderate stirring rate whereas at 70 °C, high-order morphologies were observed across a much wider range of stirring rates. The present results demonstrate that both polymerization temperature and stirring rate can significantly affect the self-assembly process in PISA.

中文翻译：

---

搅拌速率对水性RAFT乳液PISA衍生嵌段共聚物纳米粒子形貌的影响

使用大分子RAFT试剂聚(聚(乙二醇)甲醚丙烯酸酯)-TTC和聚(聚(乙二醇)甲醚甲基丙烯酸酯)-TTC扩链，研究了搅拌速率对水性RAFT乳液PISA中纳米粒子形态的影响。分别为苯乙烯/丙烯酸正丁酯（共聚物）和甲基丙烯酸甲酯（MMA）。首先通过在 50 °C 和 70 °C 下对 MMA 体系进行聚合来研究温度的影响，结果表明在 70 °C 下有利于高阶形态的形成。对两个体系都探讨了搅拌速率的影响，结果表明影响程度取决于聚合温度。在 50 °C 时，仅在中等搅拌速率下才能获得高阶形态，而在 70 °C 时，在更广泛的搅拌速率范围内观察到高阶形态。目前的结果表明，聚合温度和搅拌速率都会显着影响 PISA 中的自组装过程。