Mixed monolayers of quaternary ammonium gemini Surfactants with octadecyl alcohol

Zhou Dong-Liang; Yang Hong-Wei; Zhu Pu-Xin; Sun Yu-Hai; Feng Yu-Jun; Wu Da-Cheng

HERO ID

4937213

Reference Type

Journal Article

Year

2007

HERO ID 4937213
In Press No
Year 2007
Title Mixed monolayers of quaternary ammonium gemini Surfactants with octadecyl alcohol
Authors Zhou Dong-Liang; Yang Hong-Wei; Zhu Pu-Xin; Sun Yu-Hai; Feng Yu-Jun; Wu Da-Cheng
Journal Gaodeng Xuexiao Huaxue Xuebao / Chemical Journal of Chinese Universities
Volume 28
Issue 5
Page Numbers 932-935
Abstract pi-A isotherms were studied for mixed monolayers formed from each of two cationic gemini surfactants(dissymmetrical gemini surfactant 12-2-16 and symmetrical gemini surfactant 12-2-12) with octadecyl alcohol (C18H37OH) on air-water interface. The mixed surface excess free energy, Delta G(M)(exc), was analyzed for each mixed monolayer with various mixed molar ratios at different surface pressures under the point of phase separation; to analyze the compatibility of each of the gimini surfactants and the fatty alcohol in the monolayer. The results show that Delta G(M)(exc) changes with the nature of the mixed molecules, mixed molar ratio, and surface pres sure. Mixed monolayers of 12-2-16 and C18H37OH were considered as incompatible because Delta G(M))(exc) > 0 in all mixed molar ratios. While for a system where 12-2-12 is mixed with C18H37OH, the compatibility of the mixed monolayer lies mostly on the mixed molar ratio. The values of Delta G(M)(exc) augment with increasing the C18H37OH molar ratio, changing from a net attractive interaction to a net repulsive interaction between 12-2-12 and C18H37OH with a critical point of C18H37OH molar ratio 0. 65 added in the mixed system. When the mixing system is thermodynamically favored, increasing surface pressure will promote the mixing; In contrast, increasing surface pressure for a repulsive mixed system will be more thermodynamically unfavorable.
Wosid WOS:000246787400032
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword quaternary ammonium Gemini surfactant; octadecyl alcohol; mixed monolayer; mixed surface excess free energy