In:
Journal of Surfactants and Detergents, Wiley, Vol. 22, No. 5 ( 2019-09), p. 1109-1117
Abstract:
It is well known that CO 2 reacts with primary and secondary amines in aqueous solutions and forms carbamates. This reaction can have consequences when studying the self‐assembly of amines. In this article, we discuss the practical challenges when working with an alkyl Y‐shaped amine (Y12‐amine) and demonstrate how the formation of carbamate species influences the physicochemistry of the amine‐based surfactant. A drift in dynamic surface tension was observed for Y12‐amine at pH above pKa due to the reaction with the naturally occurring CO 2 from the atmosphere. The drift in dynamic surface tension was more pronounced at pH above pKa, than at and below pKa. Furthermore, the drift in dynamic surface tension of Y12‐amine at pH 12 also affected the surfactant's critical micelle concentration (CMC). CMC of Y12‐amine determined by the pendant drop at the air/water interface was almost five times higher than at the N 2 /water interface. The latter result was in agreement with the one determined by monitoring the change in chemical shift of 1 H NMR in a N 2 atmosphere. Moreover, it was also shown that the adsorption of the amine at different interfaces influences carbamate formation.
Type of Medium:
Online Resource
ISSN:
1097-3958
,
1558-9293
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
2109638-7
