Title:	On the polymorphism of the smectic A phases of highly polar compounds
Authors:	Madhusudana, N.V.
Keywords:	Smectic A Polymorphism Reentrant phases Bilayer Smectics Induced Smectic Phases
Issue Date:	Oct-1983
Publisher:	Indian Academy of Sciences, Bangalore, India.
Citation:	Proceedings of the Indian Academy of Sciences (Chemical Sciences), 1983, Vol. 92, p509 -525.
Abstract:	The smectic A phase is characterized by a layered arrangement of rod-like molecules, with the average orientation of the molecules normal to the layers and a liquid-like organization within the layers. When the molecules have a strongly polar end group (like C=N, -NO2 etc.,), neighbouring molecules prefer an antiparallel orientation. This results in a bilayer structure, with a layer spacing much larger than the molecular length. In many compounds, the structure of the bilayer is sensitive to temperature (or pressure). This results in some interesting phenomena: (a) reentrant phases, as for example, the appearance of a nematic phase below the temperature range of existence of the A phase; (b) a number of polymorphic forms of smectic A; and (c) an 'induced smectic A' phase when the compounds with the highly polar terminal groups are mixed with weakly polar compounds even when neither compound by itself exhibits the A phase. This article gives a brief summary of recent results on all these aspects.
URI:	http://hdl.handle.net/2289/1057
ISSN:	0253-4134
Copyright:	Indian Academy of Sciences, Bangalore, India.
Appears in Collections:	Research Papers (SCM)

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