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Proceedings Paper

High-pressure differential thermal analysis (DTA) of the phase behaviors of didodecyl-dimethylammoniumbromide (DDAB) and ditetradecyl-dimethylammoniumbromide (DTAB)
Author(s): F. Hamann; John Reuter; A. Wuerflinger; Malgorzata Godlewska; Patrycja Dynarowicz
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Paper Abstract

Dialkyldimethylammonium halides are known for their applications as commercial detergents and for their membrane-mimetic properties. They display both thermotropic and lyotropic liquid crystalline properties. In this work we establish the T(p)-phase diagrams of two representatives, namely didodecyl- and ditetradecyl-ammonium bromides. The transitions between crystal, smectic Ii and smectic I phases were recorded using a high-pressure differential thermal analysis device. For both compounds the stable range of smectic II phase is pressure-limited, resulting in a triple point crystal/smectic II/smectic I. Enthalpy changes at ambient pressure have been determined with the aid of a commercial heat flux differential scanning calorimeter. Volume changes were calculated from the slopes of the transitions lines, employing the Clausius Clapeyron equation.

Paper Details

Date Published: 1 January 1998
PDF: 4 pages
Proc. SPIE 3319, Liquid Crystals: Chemistry and Structure, (1 January 1998); doi: 10.1117/12.301277
Show Author Affiliations
F. Hamann, Univ. Bochum (Germany)
John Reuter, Univ. Bochum (United States)
A. Wuerflinger, Univ. Bochum (Germany)
Malgorzata Godlewska, Jagiellonian Univ. (Poland)
Patrycja Dynarowicz, Jagiellonian Univ. (Poland)


Published in SPIE Proceedings Vol. 3319:
Liquid Crystals: Chemistry and Structure
Marzena Tykarska; Roman S. Dabrowski; Jerzy Zielinski, Editor(s)

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