Stabilization of colloidal suspensions by means of highly-charged nanoparticles

摘要

We employ a novel Monte Carlo simulation scheme to elucidate thestabilization of neutral colloidal microspheres by means of highly-chargednanoparticles [V. Tohver et al., Proc. Natl. Acad. Sci. U.S.A. 98, 8950(2001)]. In accordance with the experimental observations, we find that smallnanoparticle concentrations induce an effective repulsion that preventsgelation caused by the intrinsic van der Waals attraction between colloids.Higher nanoparticle concentrations induce an attractive potential which is,however, qualitatively different from the regular depletion attraction. We alsoshow how colloid-nanoparticle size asymmetry and nanoparticle charge can beused to manipulate the effective interactions.