Abstract
Foam and wetting films from PEO-PPO-PEO triblock copolymers Synperonic P85 and F108 are studied under the identical conditions, using microinterference method. The range of background electrolyte concentration, where DLVO (electrostatic and van der Waals) forces and non-DLVO (steric) forces act in the films, is determined. From the dependence of the film thickness on pH, it is unambiguously shown that electrostatic interactions (i.e., the potential and surface charge) in the foam and wetting films caused by the presence of nonionic polymer surfactants arise due to the preferential adsorption of OH− ions at the solution-air interface. The films obtained below the critical pH values are sterically stabilized; i.e., a decrease in pH induces a transition from electrostatic to steric stabilization. Three-layer models are designed for both types of films that allow to calculate electrostatic disjoining pressure Πel. The values of ϕ0 potential of the foam film are used to calculate Πel in wetting films. A relation between the isoelectric state of foam and wetting films and their stability is found to exist in the range of pH corresponding to electrostatic stabilization. Metastable films, film rupture, or the transition to sterically stabilized films were also found.
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References
Scheludko, A., Adv. Colloid Interface Sci., 1967, vol. 1, p. 391.
Derjaguin, B. V. and Churaev, N. V., Smachivayushchie Plenki (Wetting Films), Moscow: Nauka, 1984.
Derjaguin, B. V., Theory of Stability of Colloids and Thin Films, New York: Consultants Bureau, 1989.
Derjaguin, B. V., Churaev, N. V., and Muller V. M., Surface Forces, New York: Consultants Bureau, 1987.
Israelashvili, J. N., Intermolecular and Surface Forces, London: Academic Press, 1985.
De Frejter, J., in Thin Liquid Films, Ivanov, I.B., Ed., New York: Marcel Dekker, 1988, p. 1.
Churaev, N. V. and Zorin, Z. M., Adv. Colloid Interface Sci., 1992, vol. 40, p. 109.
Exerowa, D. and Kruglyakov, P. M., Foam and Foam Films, Amsterdam: Elsevier, 1998.
Exerowa, D., Adv. Colloid Interface Sci., 2002, vol. 96, p. 75.
Alexandridis, P. and Hatton, T. A., Colloids Surf. A, 1995, vol. 96, p. 1.
Nonionic Surfactants: Polyoxyalkylene Block Copolymers, Nace, V.M., Ed., New York: Marcel Dekker, 1966.
Amphiphilic Block Copolymers: Self-Assembly and Applications, Alexandridis, P. and Lindman, B., Eds., Amsterdam: Elsevier, 1997.
Sedev, R., Kolarov, T., and Exerowa, D., Colloid Polymer Sci., 1995, vol. 273, p. 906.
Sedev, R., Ivanova, R., Kolarov, T., and Exerowa, D., J. Disp. Sci. Technol., 1997, vol. 18, p. 751.
Exerowa, D., Sedev, R., Ivanova, R., Kolarov, T., and Tadros, Th. F., Colloids Surf. A, 1997, vol. 123, p. 277.
Exerowa, D., Ivanova, R., and Sedev, R., Prog. Colloid Polymer Sci., 1998, vol. 109, p. 29.
Sedev, R. and Exerowa, D., Adv. Colloid Interface Sci., 1999, vol. 83, p. 111.
Diakova, B., Kaisheva, M., and Platikanov, D., Colloids Surf. A, 2001, vol. 190, p. 61.
Diakova, B., Platikanov, D., Atanassov, R., and Kaisheva, M., Adv. Colloid Interface Sci., 2003, vol. 104, p. 25.
Scheludko, A. and Exerowa, D., Comm. Dept. Chem. Bulg. Acad. Sci., 1959, vol. 7, p. 123.
Kolarov, T. and Iliev, L., Ann. Univ. Sofia Fac. Chim., 1974, vol. 69, p. 107.
Exerowa, D., Zacharieva, M., Cohen, R., and Platikanov, D., Colloid Polymer Sci., 1979, vol. 257, p. 1089.
Exerowa, D., Kolarov, T., and Khristov, Khr., Colloids Surf., 1987, vol. 22, p. 171.
Kolarov, T., Cohen, R., and Exerowa, D., Colloids Surf., 1989, vol. 42, p. 49.
Zorin, Z., Platikanov, D., and Kolarov, T., Colloids Surf., 1987, vol. 22, p. 147.
Donners, W. A. B., Rijnbout, J. B., and Vrij, A., J. Colloid Interface Sci., 1977, vol. 60, p. 540.
Sergeeva, I. P., Sobolev, V. D., and Churaev, N. V., Colloid J., 1990, vol. 52, p. 1129.
Malmsten, M., Linse, P., and Cosgrove, T., Macromolecules, 1992, vol. 25, p. 2474.
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Exerowa, D., Churaev, N.V., Kolarov, T. et al. Foam and wetting films from amphiphilic block copolymers: Isoelectric state and stability. Colloid J 68, 155–161 (2006). https://doi.org/10.1134/S1061933X06020062
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DOI: https://doi.org/10.1134/S1061933X06020062