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Indexed by:期刊论文

Date of Publication:2014-05-01

Journal:JOURNAL OF SURFACTANTS AND DETERGENTS

Included Journals:SCIE、EI

Volume:17

Issue:3

Page Number:383-390

ISSN No.:1097-3958

Key Words:Switchable surfactants; CO2; N-Alkylimidazole; Emulsification

Abstract:In order to overcome the hydrolysis of 2-alkyl-1-hydroxyethyl imidazoline and its unsatisfactory emulsification-demulsification switchability to water-alkane, the long-chain N-alkylimidazole compounds were synthesized by n-octyl bromide, n-decyl bromide, n-dodecyl bromide, n-tetradecyl bromide and n-hexadecyl bromide with imidazole, respectively and characterized by MS, H-1 NMR and FTIR. The long-chain N-alkylimidazole compounds can be reversibly transformed into charged surfactants by exposure to CO2. Surface tension values indicated that N-alkylimidazolium bicarbonates had excellent surface activity compared with corresponding conventional surfactants with a lower gamma (CMC). The surface behaviors of the five surfactants can be illustrated by A (min). Five conductivity cycles by bubbling CO2 and N-2 alternately indicated that these surfactants could be switched by CO2 reversibly and repeatedly. Emulsions were repeatedly stabilized for five cycles by N-alkylimidazolium bicarbonate and broken by bubbling N-2 through the solutions to reverses the reaction, releasing CO2.