Pressure dependence on the Flory-Huggins interaction parameter of poly(N-isopropylacrylamide) gels

被引:46
作者
Nakamoto, C
Kitada, T
Kato, E
机构
[1] OSAKA CITY UNIV,FAC ENGN,DEPT APPL PHYS,OSAKA 558,JAPAN
[2] KOBE UNIV MERCANTILE MARINE,DEPT GEN EDUC,KOBE 658,JAPAN
关键词
D O I
10.1016/0966-7822(96)00022-6
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Pressure dependence of the Flory-Huggins interaction parameter for poly (N-isopropylacrylamide)/water gel is obtained by measuring the swelling ratio of the gel in equilibrium under hydrostatic pressure up to about 100 MPa and by employing a mean field theory based on the Flory-type of the Gibbs free energy formula. The interaction parameter strongly depends on the volume fraction of a gel network and also on solvent pressure. In the swollen phase equilibrium of a gel under pressure, both the enthalpy and entropy increase with pressure, the second virial term decreases inversely and the interaction parameter is an increasing function of pressure. It can be seen that hydrostatic compression strengthens the hydrophobic interaction between polymer segments because of a loosening hydrogen-bond structure near the monomer unit.
引用
收藏
页码:17 / 31
页数:15
相关论文
共 27 条
[1]   LARGE-SCALE HETEROGENEITIES IN RANDOMLY CROSS-LINKED NETWORKS [J].
BASTIDE, J ;
LEIBLER, L .
MACROMOLECULES, 1988, 21 (08) :2647-2649
[2]  
CANDAU S, 1982, ADV POLYM SCI, V44, P27
[3]   INTENSITY OF LIGHT SCATTERED FROM POLYMERIC GELS - INFLUENCE OF THE STRUCTURE OF THE NETWORKS [J].
CANDAU, SJ ;
YOUNG, CY ;
TANAKA, T .
JOURNAL OF CHEMICAL PHYSICS, 1979, 70 (10) :4694-4700
[4]   CRITICAL PHENOMENA AND TRANSITIONS IN SWOLLEN POLYMER NETWORKS AND IN LINEAR MACROMOLECULES [J].
ERMAN, B ;
FLORY, PJ .
MACROMOLECULES, 1986, 19 (09) :2342-2353
[5]  
Flory PJ, 1953, PRINCIPLES POLYM CHE
[6]   VOLUME PHASE-TRANSITION IN A NONIONIC GEL [J].
HIROKAWA, Y ;
TANAKA, T .
JOURNAL OF CHEMICAL PHYSICS, 1984, 81 (12) :6379-6380
[7]   CRITICAL-POINTS OF THE VOLUME PHASE-TRANSITION IN N-ISOPROPYLACRYLAMIDE GELS [J].
HIROTSU, S .
JOURNAL OF CHEMICAL PHYSICS, 1988, 88 (01) :427-431
[8]   SOFTENING OF BULK MODULUS AND NEGATIVE POISSON RATIO NEAR THE VOLUME PHASE-TRANSITION OF POLYMER GELS [J].
HIROTSU, S .
JOURNAL OF CHEMICAL PHYSICS, 1991, 94 (05) :3949-3957
[10]  
ILAVSKY M, 1982, POLYM BULL, V7, P107