nently involved in the alternate direct transfer of the aqueous Dispersions of discrete metal-oxide submicroparticles in organic suspension into an organic solvent, notably owing to the solvents of medium polarities are uneasy to generate and weakly complex interplay of capillary forces (1-3). Upon miscibildocumented. We address this topic along two general methods ity of the initial and targeted suspension media, selective focusing on silica. Successive transfers of colloidal particles from partitioning between bulk and solid interface is expected to water into n-propanol and then into 1,2-dichloroethane by azeomodulate the stability in the ultimate equilibrium regime. tropic distillation yield a stable organosol. The particles are found Stable suspensions of discrete silica spheres have proven to be propanol-coated by surface esterification to the extent of useful models to investigate the thermodynamics of colloidal 0.40 nm 2 per molecule. Alternatively, centrifugation-redispersion systems; much understanding was obtained in apolar media cycles make it possible to obtain stable suspensions of unaltered silica in methanol and acetonitrile starting from an aqueous sili-by coating silica particles prepared after the methods of casol. Particles are characterized by various methods including Sto Β¨ber et al. with hydrophobes (4-7
), but solvents of internitrogen adsorption, transmission electron microscopy, dynamic mediate polarity have attracted less attention (8-12). Exlight scattering, and electrophoresis. The stabilities of these sustending the potentialities of colloidal suspensions toward pensions in various organic solvents are investigated with special organic solvents of higher permittivity is desirable for acaconcern for the role of residual water. Stabilization of silica in demic and practical purposes, allowing access to a wider methanol is inconspicuously related to solvent permittivity and domain of organic grafting reactions, while providing alterprominently dependent on the presence of adsorbed water. In connate modulations of Debye lengths and refractive indices.
trast, the acetonitrile silicasol, which is unaffected by residual wa-Proceeding with colloidal aqueous silica suspensions, we ter, displays electrophoretic behavior compatible with electrostatic here address two processes of transfer of the particles into stabilization.