A self-diffusion study in aqueous solution and lyotropic mesophases of amphiphilic block copolymers

被引：23

作者：

Coppola, L ^{[1
]}

Oliviero, C ^{[1
]}

Pogliani, L ^{[1
]}

Ranieri, GA ^{[1
]}

Terenzi, M ^{[1
]}

机构：

[1] Univ Calabria, Dept Chem, I-87036 Cosenza, Italy

来源：

COLLOID AND POLYMER SCIENCE | 2000年 / 278卷 / 05期

关键词：

poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide); micellar solutions; hexagonal and lamellar mesophases; pulsed field gradient spin-echo nuclear magnetic resonance experiments; micellar self-diffusion;

D O I：

10.1007/s003960050536

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 [物理化学]; 081704 [应用化学];

摘要：

Water-soluble poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PPO) triblock copolymers are high-molecular-weight nonionic copolymers and form micellar solutions and liquid-crystalline mesophases in water. We studied the temperature dependence of polymer and water self-diffusion in solutions and lyotropic mesophases of the PEO13 PPO30 PEO13/water and PEO21 PPO47 PEO21/water binary systems. The self-diffusion measurements were performed by means of the pulsed field gradient spin-echo NMR method. The analysis of the water mobility was realised using "the obstruction factor" and "the two-site model", which consider the reduction of the water self-diffusion due to the microstructure of the lyotropic aggregates and to the presence of one part of the solvent bound to the polymer aggregate surfaces. We calculated the water obstruction factors and the hydration numbers as a function both of the polymer composition and of the temperature. The results are compared with the data obtained in mesophases formed by classical surfactants.

引用

页码：434 / 442

页数：9

共 26 条

[1]

Structural polymorphism of amphiphilic copolymers: Six lyotropic liquid crystalline and two solution phases in a poly(oxybutylene)-b-poly(oxyethylene)-water-xylene system [J].