On the Influence of Intersurfactant H-Bonds on Foam Stability: A Study with Technical Grade Surfactants

Abstract

Abstract From the literature on the foam stability of various surfactants with C12 alkyl chains but different head groups a clear picture emerges: Foams are more stable when hydrogen bonds can form between the head groups, i. e. when the polar head group has a hydrogen bond donor and a proton acceptor. These observations suggest that hydrogen bonds between neighbouring molecules at the surface enhance foam stability. To support this hypothesis, we carried out a systematic foaming study of two types of technical grade surfactants, one of them being capable of forming H-bonds and the other one not. As was the case for the pure surfactants we found again that more stable foams are formed when the head group is capable of forming intersurfactant H-bonds: These results will certainly affect the future design of surfactants.