聚N-异丙基丙烯酰胺-聚乙二醇核壳微凝胶的制备与表征

Preparation and characterization of poly(N-isopropylacrylamide)-polyethylene glycol core-shell microgel

采用水相分散聚合法制备聚N-异丙基丙烯酰胺-聚乙二醇核壳微凝胶,用动态光散射法和电泳迁移率法研究了聚乙二醇的加入量及交联剂的种类对微凝胶特性的影响。结果表明N-异丙基丙烯酰胺-聚乙二醇微凝胶具有温敏特性且表面带负电荷;随着聚乙二醇加入量增加,微凝胶的相转变温度升高,相转变温度范围变宽,其电泳迁移率的绝对值先增大后减小,存在极大值。此外,只有具有足够多亲水-CH2-CH2-O-链节数的聚乙二醇大分子单体对N-异丙基丙烯酰胺聚合过程有稳定作用。

Core-shell microgels based on poly（N-isopropylacrylamide） （PNIPAM） and polyethylene glycol （PEG） were prepared by aqueous dispersion polymerization and characterized by dynamic light scattering and electrophoretic measurements with regard to the PEG addition and crosslinkers. The results indicated that the PNIPAM-PEG microgel was temperature sensitive and carried anionic charge on the surface. With the increase of PEG macro-monomer dosage, volume phase transition temperature increased, the transition temperature range became broad, while the absolute value of electrophoretic mobility of the microgels increased to a maximum and then decreased. In addition, only PEG macro-monomer with sufficient hydrophilic-CH2-CH2-O-chain length could stabilize microgel particles during the polymerization.