Can nanoparticles stabilize microparticle suspension?

The main purpose of this article is to verify the new stabilization mechanism caused by the formation of nanoparticle halos [V. Tohver, J.E. Smay, A. Braem, P.V. Braun, J.A. Lewis, Nanoparticle halos: a new colloid stabilization mechanism, Proc. Natl. Acad. Sci. U.S.A. 98 (2001) 8950], by adding different volume fractions of slightly positive charged zirconia nanoparticles in the negative charged micro-latex suspensions of different sizes, and observe the effect on stabilizing the suspension via jar settling experiments. The experimental results confirm that the zirconia nanoparticles do stabilize the micro-colloidal suspension at an optimal volume fraction in a finite volume settling system. The osmotic pressure exerted by nanoparticles on micro-colloids is applied to explain our experimental results.

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► In this study, we conducted a series of jar settling experiments by adding different volume fractions of slightly positive charged zirconia nanoparticles in the negative charged micro-latex suspensions.
► We confirm that the zirconia nanoparticles do stabilize the micro-colloidal suspension at an optimal volume fraction in a finite volume settling system.
► We verify the new stabilization mechanism caused by the formation of nanoparticle halos proposed by Prof. J.A. Lewis et al. [PNAS 98 (2001) 8950–8954].