Poly(N-isopropylacrylamide) (PNIPAM)-based ionic microgels with different diameters were first prepared and then used as particulate stabilizer or seed in dispersion polymerization of styrene. The role of PNIPAM-based ionic microgels could be transformed from particulate stabilizer to seed by controlling the water content in methanol–water mixture. Generally, PNIPAM-based ionic microgels served as particulate stabilizer in methanol in the absence of water, leading to the formation of spherical polystyrene nanoparticles. However, they turned into seeds when water was added into the methanol solution, with the formation of octopus-like nanoparticles. Further study demonstrated that the mechanism for this role transition was related to the special thermosensitivity of PNIPAM microgels in methanol–water mixture. They lost their thermosensitivity in pure methanol solution but restored their thermosensitivity when increasing the water content in methanol–water mixture.

中文翻译：

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通过控制甲醇-水混合物中的水含量，将聚（N-异丙基丙烯酰胺）微凝胶从稳定剂转变为种子在分散聚合中的作用

聚（N首先制备具有不同直径的基于（异丙基丙烯酰胺）（PNIPAM）的离子微凝胶，然后将其用作微粒稳定剂或种子，用于苯乙烯的分散聚合。通过控制甲醇-水混合物中的水含量，可以将基于PNIPAM的离子微凝胶的作用从颗粒稳定剂转变为种子。通常，基于PNIPAM的离子微凝胶在无水的情况下在甲醇中充当颗粒稳定剂，从而导致形成球形聚苯乙烯纳米颗粒。但是，当将水添加到甲醇溶液中时，它们变成了种子，并形成了章鱼状的纳米颗粒。进一步的研究表明，这种角色转变的机制与PNIPAM微凝胶在甲醇-水混合物中的特殊热敏性有关。