文献类型：期刊文献

英文题名：The influence of glycerol on the properties of neutral and ionically charged Lα-phases

作者：Zou, Aihua[1,2]; Hoffmann, Heinz[1]; Freiberger, Norbert[3]; Glatter, Otto[3]; Makorsky, A.[4]; Talmon, Yeshayahu[4]

机构：[1] Bayreuth Center for Colloid and Interface, University of Bayreuth, 95448 Bayreuth, Germany; [2] Laboratory for Advanced Materials, Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, 200237, China; [3] Institut für Chemie, Karl-Franzens Universit?t Graz, 8010 Graz, Austria; [4] Department of chemical Engineering, Technion-Israel Institute of Technology, Haifa, 32000, Israel

年份：2008

卷号：316

期号：1-3

起止页码：226

外文期刊名：Colloids and Surfaces A: Physicochemical and Engineering Aspects

收录：EI(收录号：20080611082064)

语种：英文

外文关键词：Elastic moduli - Nonionic surfactants - Solvents - Viscoelasticity - Yield stress

摘要：The influence of glycerol on the stability and the viscoelastic properties of two aqueous Lα-phases (Lalpha phases) have been investigated. The first Lα-phases A was an uncharged Lα-phases from a 5 wt.% solution of nonionic surfactant C12-16E6(a mixture of several ethoxylated carbon alcohols) and 240 mM of the co-surfactant ethylhexylglycerid (EHG). The second Lα-phases B had the same composition as Lα-phases A but was ionically charged by addition of 10 mM ionic surfactant sodium dodecyl sulfate (SDS). The Lα-phases A broke down when 40% (v/v) of the water was replaced by the solvent glycerol, while Lα-phases B remained stable until 80% of the water was replaced by glycerol. Contrary to Lα-phases A, Lα-phases B was highly viscoelastic with a yield stress value. The shear modulus was less dependent on the glycerol content. The shear modulus of the uncharged phase was much smaller than for Lα-phases B and decreased strongly with increasing glycerol content. The stability of the Lα-phases decreased also strongly with temperature. Small-angle X-ray scattering (SAXS) measurements showed that the interlamellar spacing of the Lα-phases B increased with increasing glycerol content. It is argued that the decrease of the shear modulus and the increase of the interlamellar spacing with glycerol make the interaction potential between the bilayers softer. Consequently, the interlamellar distance between the bilayers fluctuates stronger and the spacing becomes longer. ? 2007 Elsevier B.V. All rights reserved.