Title:	Thermal unbinding and ordering of amphiphile bilayers in the presence of salt
Authors:	Pal, Antara Bharath, P. Dastidar, Sudipta G. Raghunathan, V.A.
Keywords:	Ionic amphiphile Lamellar phase Sponge phase Unbinding transition
Issue Date:	15-Jul-2013
Publisher:	Elsevier Inc
Citation:	Journal of Colloid and Interface Science, 2013, Vol.402, p151
Abstract:	We have studied the effect of KBr on the electrostatically stabilized fluid lamellar phase of the ionic surfactant, C12-alkenylsuccinic acid (ASA). Three distinct regimes are found in the temperature - salt phase diagram of this system at a fixed ASA concentration of 20 wt.%. A collapsed lamellar phase is formed in the low-salt regime, which exhibits an unbinding transition into uncorrelated bilayers on heating. In the intermediate salt regime the opposite trend is observed, with the uncorrelated bilayers present at low temperatures ordering into a lamellar phase at higher temperatures. As far as we are aware, this is the first report of such an ordering transition of uncorrelated bilayers. In the high salt regime, the topology of the bilayer changes, resulting in a lamellar–sponge transition. All the three transitions are reversible and the corresponding transition temperatures decrease with increasing salt concentration. The occurrence of these transitions in a single amphiphile system demonstrates the strong influence of salt on the bilayer elastic moduli as well as on the inter-bilayer interactions in the present system.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/5717
ISSN:	0021-9797 1095-7103(Online)
Alternative Location:	http://dx.doi.org/10.1016/j.jcis.2013.03.063
Copyright:	2013 Elsevier
Appears in Collections:	Research Papers (SCM)

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.