Fluorescence Probe Studies of Thermosensitive N−Isopropylacrylamide Copolymers in Aqueous Solutions
Fluorescence Probe Studies of Thermosensitive N−Isopropylacrylamide Copolymers in Aqueous Solutions
复制标题
水溶液中热敏 N-异丙基丙烯酰胺共聚物的荧光探针研究
DOI：
10.1080/10587259808044310
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发表时间：
1998
影响因子：
0.7
通讯作者：
Masao Yamamoto
中科院分区：
文献类型：
--
作者：
K. Iwai;Naomi Matsumoto;Makiko Niki;Masao Yamamoto
摘要以9-（4-N，N-二甲氨基苯基）菲（DP）为分子内荧光探针，研究了N-异丙基丙烯酰胺（NIPAM）共聚物在水溶液中的温度诱导相变。DP标记的NIPAM共聚物的低临界溶解温度（LCST）取决于并入NIPAM共聚物中的共聚单体的性质和含量，即，疏水共聚单体如甲基丙烯酸甲酯（MMA）降低了LCST，亲水共聚单体如甲基丙烯酸（MAA）提高了LCST，共聚单体含量越高，LCST的变化越大。同时，NIPAM共聚物在水溶液中的微环境也依赖于它们。NIPAM与N-正丙基丙烯酰胺（NNPAM）和N-异丙基甲基丙烯酰胺（NIPMAM）的共聚物的温度诱导相变似乎非常尖锐，以及NIPAM均聚物水溶液的温度诱导相变，并且它们的LCST值与它们的共聚物组成良好相关。
Abstract Temperature-induced phase transitions of some N−isopropylacrylamide (NIPAM) copolymers in aqueous solutions were studied with 9-(4-N,N− dimethylaminophenyl)phenanthrene (DP) as an intramolecular fluorescence probe. Lower critical solution temperature (LCST) of DP-labeled NIPAM copolymers depends on the properties and contents of comonomers incorporated in the NIPAM copolymers, i.e., a hydrophobic comonomer such as methyl methacrylate (MMA) lowers the LCST, and a hydrophilic comonomer such as methacrylic acid (MAA) raises it. The higher contents of comonomers, the bigger changes of the LCST. And the micro-environments of the NIPAM copolymers in aqueous solutions also depend on them. The temperature-induced phase transitions of NIPAM copolymers with N-n−propylacrylamide (NNPAM), and N−isopropylmethacrylamide (NIPMAM) appear to be very sharp as well as that of NIPAM homopolymer aqueous solution and their LCST values are good correlated with their copolymer compositions.