Light-sensitive lamellar phases

被引：4

作者：

Zou, Aihua ^{[1
]}

Eastoe, Julian ^{[1
]}

Mutch, Kevin ^{[1
]}

Wyatt, Paul ^{[1
]}

Scherf, Guenther ^{[2
]}

Glatter, Otto ^{[3
]}

Grillo, Isabelle ^{[3
]}

机构：

[1] Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England

[2] Karl Franzens Univ Graz, Inst Chem, A-8010 Graz, Austria

[3] Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France

来源：

JOURNAL OF COLLOID AND INTERFACE SCIENCE | 2008年 / 322卷 / 02期

基金：

英国工程与自然科学研究理事会;

关键词：

L-alpha phases; light-triggered systems; SAXS; SANS;

D O I：

10.1016/j.jcis.2008.03.016

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 ; 081704 ;

摘要：

Light sensitive lamellar (L-alpha) phases have been generated in glycerol/water mixtures from blends of an inert ABA tri-block co-polymer (dimethylsiloxane-polyethylenoxide, (EO)(15)-(PDMS)(15)-(EO)(15)), and a photodestructible anionic surfactant C(6)PAS (sodium 4-hexylphenylazosulfonate). These L-alpha systems have been formulated in a 6/4 glycerol/water (v/v) mixed solvent. Rheology, small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS) and dynamic light scattering (DLS) have been used to characterize the change in phase behavior and structure after the incorporated C(6)PAS is selectively degraded by UV light incident on the L-alpha phases. The ABA co-polymer alone forms weakly structured lamellar mesophases, which are stabilized by thermal fluctuations and characterized by low shear moduli (L-alpha phase-A). Addition of CO6PS (10 mM) introduces charge stabilization, generating more ordered and stiffer L-alpha systems (L-alpha phase-B). After UV irradiation (Hg lamp) of the L-alpha-B phases, and subsequent degradation of the ionic C(6)PAS, the results of rheological and scattering studies are consistent with an irreversible change back to L-alpha phase-A type systems. These formulations display a novel transition between electrostatically- and thermally-stabilized lamellae, which may be controlled by incident UV light. (C) 2008 Elsevier Inc. All rights reserved.

引用

页码：611 / 616

页数：6