Water-induced dispersion/flocculation of colloidal suspensions in nonpolar media

Reversible Structure Formation of Aluminum Trihydroxide (ATH) Dispersions in Polydimethylsiloxane (PDMS)

“…This behavior is in accord with previous reports on the effects of water in alumina and aluminum hydroxide in alcohol dispersions . Similarly, Kandori et al , have reported water-induced flocculation for iron oxide dispersion in 2-butanone and cyclohexane while Malbrel and Samosundaran have reported water-induced flocculation for suspensions of alumina in cyclohexane.…”

“…In the presence of these interactions, small amounts of water can preferentially adsorb to the dispersed phase and link surface active molecules, such as sugar in oil, leading to flocculation . Similar rapid aggregation of hydrophilic dispersed phases in hydrophilic media have been reported for suspensions of magnesium hydroxide near the isoelectric point and for aluminum oxide suspensions in the presence of sulfate ions. , Though water-induced flocculation of aluminum oxide has been reported, the effect of water on the network structure of aluminum trihydroxide in nonpolar polymer matrices remains largely unexplored . Specifically, studies to elucidate the effect of water on the rheological properties of commercially significant ATH dispersions are necessary to understand manufacturability and processability.…”

“…20,21 Though water-induced flocculation of aluminum oxide has been reported, the effect of water on the network structure of aluminum trihydroxide in nonpolar polymer matrices remains largely unexplored. 22 Specifically, studies to elucidate the effect of water on the rheological properties of commercially significant ATH dispersions are necessary to understand manufacturability and processability. The purpose of this work is to better understand how water influences the rheological behavior of a model ATH−silicone compound.…”

Copper Phthalocyanine–Mica Interactions in Nonaqueous Media

“…Just how nonaqueous dispersions are stabilized is the subject of considerable debate (1)(2)(3)(4)(5)(6)(7)(8). Van der Hoeven and Lyklema (1), Kitahara (2), and Morrison (3) have reviewed the influence of ionic surfactants on the surface potentials of particles present in nonaqueous dispersions.…”

Nucleation, Growth, and Arrested Growth in Confined Space

“…For example, it has been observed that negatively charged silica particles readily deposit in presence of negatively charged polymer latexes 5 . It is worth noting that not only in aqueous media but also in apolar solvents the stability of particle dispersions can be governed by the presence of a net charge on the surface or by double-layer electrostatic repulsions 6,7 . It has been suggested that surface charging in solvents with low dielectric constant could be sustained by speciWc mechanisms such as exchange of protons between particle surface and surrounding medium 8 .…”