Mesophase formation and thermal behavior of catanionic mixtures of gemini surfactants with sodium alkylsulfates

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Yujie J Wang (Author) Other; Eduardo F Marques (Author) FCUP

Journal

Title: Journal of Thermal Analysis and Calorimetry

Vol. 100 No. 2

Pages: 501-508

ISSN: 1388-6150

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 9 Citations

Scopus - 9 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

CORDIS: Physical sciences > Physics > Thermodynamics > Applied thermodynamics ; Physical sciences > Chemistry > Physical chemistry > Surface chemistry

Other information

Authenticus ID: P-003-742

DOI: 10.1007/s10973-009-0653-8

Abstract (EN): The thermal behavior for three homologous series of cationic geminis surfactants of the type n-2-n, alkanediyl-alpha,omega-bis(alkyldimethylammonium bromide), with n = 12, 14, 16, and 18, and sodium alkyl sulfates, SC (m) S, with m = 12, 14, and 16, is reported here. The cationic/anionic molar ratio is kept at 1:2 (equicharged mixtures), and salt is also present. Polarizing light microscopy and differential scanning calorimetry show a stepwise fusion for the mixtures with appearance of several mesophases between the crystalline structures and the isotropic liquid. A main endothermic transition is observed, associated with partial chain melting and consequent loss of crystalline order, followed by a transition to a smectic liquid crystal. The phase transition thermodynamics is interpreted in terms of an interplay between van der Waals chain-chain interactions and ionic head group interactions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8