Formation, physicochemical and interfacial study of carbamate surfactants
Artikel i vetenskaplig tidskrift, 2018

Carbon dioxide is commonly used as pH regulator in switchable surfactant systems and in the formation of alkyl ammonium-alkyl carbamate ion-pair. Its use to form a meta-stable anionic surfactant has been less explored and can impart a cleavable character to the amphiphile. The reaction between CO2 and an alkylamine, N,N-di(propylamino)dodecylamine (Y12-amine), under alkaline pH conditions, produced a stable anionic carbamate-based surfactant (Y12-carbamate). By heating and exposure to N-2, anionic Y12-carbamate could slowly be reverted into Y12-amine. The surface activity of Y12-amine and Y12-carbamate was investigated by surface tension measurements. To study the behavior of Y12-amine at the gas-water interface during CO2 exposure, we used the pendant drop technique with a sealed chamber where the gas composition could be controlled. The Y12-carbamate had a higher CMC than Y12-amine at pH 12, and was also less surface active. The ion pair Y12-ammonium- Y12-carbamate, obtained at neutral pH, exhibited the lowest CMC and the highest surface activity. The interfacial formation of anionic Y12-carbamate induced an increase in surface tension. When CO2 was exchanged to N-2, the migration from the bulk to the interface of Y12-amine induced a decrease in surface tension. The rate was dependent on the concentration of Y12-amine.

Carbon dioxide

Ion pair

Interface

Surface tension

Anionic carbamate

Surfactant

Amine

Författare

Anna-Karin Hellström

Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

H. Oskarsson

Akzo Nobel Surface Chemistry AB

Romain Bordes

Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Journal of Colloid and Interface Science

0021-9797 (ISSN)

Vol. 511 84-91

Ämneskategorier

Fysikalisk kemi

DOI

10.1016/j.jcis.2017.09.100

PubMed

28988009