Rate-Determining Step of Deswelling for Conventional and Macroporous Poly(N-isopropylacrylamide) Gels
Rate-Determining Step of Deswelling for Conventional and Macroporous Poly(N-isopropylacrylamide) Gels
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常规和大孔聚（N-异丙基丙烯酰胺）凝胶消溶胀的速率确定步骤
DOI：
10.1246/bcsj.72.357
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发表时间：
1999
影响因子：
4
通讯作者：
F. Takahashi
中科院分区：
文献类型：
--
作者：
N. Kato;F. Takahashi
The kinetic parameters of deswelling for conventional and macroporous poly(N-isopropylacrylamide) gels were determined in order to point out the rate-determining step on the deswelling process in a NaCl or KCl solution. The apparent activation energy for the deswelling of the conventional gel in water (130 kJ mol−1) was larger than that of the macroporous gel in water (25 kJ mol−1). The split process of the skin layer, which was formed on the surface of the gel by heating from outside of gel, was considered concerning the rate-determining step in the case of the conventional gel. The activation entropy changes at 313 K (ΔS313’s) of the macroporous gel were determined to be −65 J K−1 mol−1 in 0.1 M NaCl (1 M = 1 mol dm−3), of which the cation exhibits a structure-forming property, and 180 J K−1 mol−1 in 0.1 M KCl, of which the cation exhibits a structure-breaking property. The sign of ΔS313 for the macroporous gel was negative at higher than 0.3 M NaCl or KCl. In order to point out the rate-determining ste...
