DLVO surface forces in liquid films and statistical mechanics of colloidal oscillatory structural forces in dispersion stability

This paper focuses on the theory of the dispersion stability considering two models. In the classical DLVO model of surface forces, the interactions between two particles consist of two terms: the London-van der Waals attractive interaction and the electrostatic repulsive interaction in the frame of the Debye-Huckel theory. The solvent, the aqueous solution of the electrolyte, was considered the continuous phase. The film stability criteria are Pr > pi and dPr/dh > 0. Henderson and Lozada-Cassou (HC) applied the statistical mechanics approach to calculate the film free energy to predict the dispersion stability by considering two large hard spheres as colloidal particles immersed in a fluid of dispersed small particles (the solvent). HC applied the radial distribution function g(r) to calculate the free oscillatory structural energy using W(r) = - kT ln g(r). HC's theoretical approach was also applied to the particle collective interactions in the film and explains the stability of film formed from complex fluids (e.g., micellar and colloidal dispersions). The differences between the solvation oscillatory layering forces and colloidal oscillatory structural forces are discussed. The application of the DLVO model to the dispersion stability is critically reviewed. The role of nanobubbles in the dispersion stability is discussed.

Automated summary

This paper explores two models for dispersion stability theory. The classical DLVO model considers the attractive London-van der Waals interaction and electrostatic repulsive interaction in the frame of the Debye-Huckel theory. The solvent, an aqueous electrolyte solution, is treated as the continuous phase. Henderson and Lozada-Cassou (HC) use statistical mechanics to calculate the film free energy and predict dispersion stability by considering hard spheres immersed in a fluid of dispersed small particles. HC's theoretical approach also explains the stability of complex fluid films and discusses the differences between solvation oscillatory layering forces and colloidal oscillatory structural forces. The application of the DLVO model to dispersion stability is critically reviewed, and the role of nanobubbles in dispersion stability is discussed.