Abstract:

The effects of different types of surfactants on the foaming performance of organic solvents with different polarities were investigated. Compared with the solution and foaming performance of conventional surfactant stearyl alcohol ethoxylate, the special surfactants showed excellent performance in the aspects of maximum foam volume, drainage half-life and bubble size distribution. Compared with the addition of C18E9, the introduction of FC-170C into formamide raised the maximum foam air content from 77.7% to 80.6%, and extended the half-life from 123 s to 394 s. Similarly, the addition of PDMS to ethyl acetate raised the maximum foam air content from 25.4% to 30.6%, and increased the half-life from 53 s to 55 s. The introduction of DDAB altered the non-foaming status of benzyl acetate, achieving a maximum foam air content of 39.0% and a half-life of 64 s. The addition of FC-170C changed toluene from non-foaming to foaming, resulting in a maximum foam air content of 44.4% and a half-life of 113 s. The foaming performance was optimal upon the addition of DDAB to decane. The maximum air content of the foam reached 35.9%, with a half-life of 42 s. As to these organic solvents, the foaming performance of special surfactants generally surpassed that of regular surfactant. Solvents with strong polarity were more likely to produce stable foams, the foaming performance of strong polar solvents was superior to that of weak polar solvents. For the same surfactant added, compared with other solvents, the foam produced by formamide solution was more stable and the foam volume was also larger.

Key words: special surfactant, organic solvent, foaming performance