Publications

Dispersion of titania nanoparticles in polydimethylsiloxane fluids using grafted low molecular weight polymers

Bell, Nelson S.; Frischknecht, Amalie F.

Nanoparticle interactions and their impact on particle dispersion and rheology are well known to be functions of the interfacial structure between the particle and the fluid phase. The dispersion and flow properties of a titania nanopowder were evaluated in polydimethylsiloxane fluid using ''grafted to'' surface modification of the titania with short molecular weight PDMS polymers. The interaction energy between particles was modeled using analytical expressions as well as dynamic functional theory for polymer surface chains. Particle dynamics as a function of volume fraction were characterized using light scattering, acoustic spectroscopy, and shear and oscillatory measurements. Autophobic dewetting is a novel short range interaction in this system that may be impacting the maximum packing fraction of particles in a suspension.