Initial solvent driven non-equilibrium behavior of polymer nanocomposites with varying size ratios between nanoparticles and polymers

Abstract

The adsorbed polymer layer near particle surface is important in polymer nanocomposties (PNCs) as it controls particle stability and resulting polymer properties. Therefore, extensive studies have been carried out to characterize the structure of adsorbed polymers and detailed adsorbed polymer-particle interactions; but most of them were limited to equilibrium states. However, polymers experience non-equilibrium state during the PNC process as it requires initial mixing of polymer and particles in solutions and solvent evaporation and are often kinetically trapped because of the slow dynamics of polymers. Here, we investigate the role of initial casting solvent on the adsorption layer at interfaces and the resulting rheological property of PNCs where we systemically vary the size ratios between particles and polymers and show the casting solvent changes the layer thickness of polymer adsorption on nanoparticle surfaces.