Effect of sodium alginate and polyvinyl alcohol polymers on the foaming performance of dodecyl dimethyl betaine solutions

The zwitterionic ionic surfactant dodecyl dimethyl betaine (BS-12) exhibits both positive and negative charges simultaneously, and the charged nature of the incorporated polymer may impact the performance of BS-12. In this paper, the characteristics of anionic composite foam solutions formed by the electrostatic interaction between -COO- of sodium alginate (SA) and -NH+ of BS-12, as well as the zwitterionic composite foam solutions formed by hydrogen bonding between polyvinyl alcohol (PVA) and BS-12, were utilized to investigate the effects of SA and PVA, respectively, as stabilizers on the foam properties of their solutions. The results showed that the pure BS-12 solution exhibited excellent foaming performance, while the defoaming rate after 5 min reached over 90%. In both types of polymer-enhanced foam systems, the addition of PVA resulted in a decrease in foaming performance for BS-12 and was only effective in improving the foam stability of BS-12 at high concentrations of the foam solution. In contrast, the addition of SA exhibited a positive synergistic effect on the composite system BS-12 foam solution, with an optimal foaming concentration of 1 wt% BS-12 and 0.2 wt% SA. However, its impact on the stability performance of low-concentration BS-12 foam solutions was more significant than that of high-concentration ones. Therefore, the type and concentration of polymer should be strictly controlled in the practical application of BS-12, and we suggest using anionic polymers with low concentrations to improve the foaming and foam stability of BS-12 in practical application.