Department of Chemistry, University of Helsinki, P.O. Box 55, A.I. Virtasen aukio 1, FIN-00014 HY Helsinki, Finland.
VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT Espoo, Finland.
Langmuir. 2022 May 3;38(17):5135-5148. doi: 10.1021/acs.langmuir.1c02224. Epub 2021 Nov 9.
Poly(diisopropylaminoethyl methacrylate) (PDPA) is a pH- and thermally responsive water-soluble polymer. This study deepens the understanding of its phase separation behavior upon heating. Phase separation upon heating was investigated in salt solutions of varying pH and ionic strength. The effect of the counterion on the phase transition upon heating is clearly demonstrated for chloride-, phosphate-, and citrate-anions. Phase separation did not occur in pure water. The buffer solutions exhibited similar cloud points, but phase separation occurred in different pH ranges and with different mechanisms. The solution behavior of a block copolymer comprising poly(dimethylaminoethyl methacrylate) (PDMAEMA) and PDPA was investigated. Since the PDMAEMA and PDPA blocks phase separate within different pH- and temperature ranges, the block copolymer forms micelle-like structures at high temperature or pH.
聚（二异丙基氨基乙基甲基丙烯酸酯）（PDPA）是一种 pH 值和温度响应型水溶性聚合物。本研究加深了对其加热时相分离行为的理解。在不同 pH 值和离子强度的盐溶液中研究了加热时的相分离。氯离子、磷酸盐离子和柠檬酸盐离子明显证明了抗衡离子对加热时相转变的影响。在纯水中不会发生相分离。缓冲溶液表现出相似的浊点，但相分离发生在不同的 pH 值范围和不同的机制中。研究了包含聚（二甲基氨基乙基甲基丙烯酸酯）（PDMAEMA）和 PDPA 的嵌段共聚物的溶液行为。由于 PDMAEMA 和 PDPA 嵌段在不同的 pH 值和温度范围内相分离，因此嵌段共聚物在高温或高 pH 值下形成类似胶束的结构。
