Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2014-05-01

Journal: JOURNAL OF SURFACTANTS AND DETERGENTS

Included Journals: EI、SCIE

Volume: 17

Issue: 3

Page Number: 383-390

ISSN: 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.