Stability of aqueous foams with polymer additives: II. Effects of temperature

Abstract

The stability of aqueous foams with polymer additives has been studied at temperatures ranging from 30 to 80°C. It is found that the enhancement of stability due to the addition of water-soluble polymer additives as reported by D. S. H. S. Sarma, J. Pandit, and K. C. Khilar ( J. Colloid Interface Sci. 124, 339 (1988)) is substantially retained, although it is reduced at higher temperatures. In the case where cosurfactant is the only additive, the enhancement of stability is entirely lost at about 70°C. It is also found that the decrease in drainage half-life and the increase in initial drainage rate are gradual with the increase in temperature, without any indication of sudden transition. The modified lamella drainage analysis is extended and used to qualitatively describe this effect. The experimental data and the analytical results are used to discern the importance of interfacial mobility in the variation of stability with temperature.