Enthalpy of formation of crystalline surfactant molecular complexes

Citation
N. Iimura et al., Enthalpy of formation of crystalline surfactant molecular complexes, THERMOC ACT, 360(2), 2000, pp. 121-129
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
THERMOCHIMICA ACTA
ISSN journal
0040-6031 → ACNP
Volume
360
Issue
2
Year of publication
2000
Pages
121 - 129
Database
ISI
SICI code
0040-6031(20000928)360:2<121:EOFOCS>2.0.ZU;2-A
Abstract
The standard enthalpy of formation of novel chemical species - crystalline cationic surfactant molecular complexes was studied to elucidate the bondin g nature, serially scanning over the different surfactant chain-length homo logs and various additive species. The enthalpy was not large, but was obvi ously dependent on the surfactant chain length and the chemical nature of t he additive species. The typical complexes comprising long allyl chain surf actants were formed endothermally, while in short alkyl chain homologs the process was exothermic. By examining the thermal aspect, it was suggested t hat the typical complexes of long alkyl-chain surfactants were derived not from attractive energetic force factors, but rather from entropic factors a ssociated with the occurrence of severe disorder caused by heavy thermal ag itation in the complex crystalline state. (C) 2000 Elsevier Science B.V. Al l rights reserved.