Polymer Coated Nanoparticle As Additives for Interfacial Modification

Additives that can tailor oil-water interfacial properties are potentially useful for enhanced oil recovery processes. Here, we investigate polymer coated nanoparticles as additives for reducing oil-water interfacial tension and stabilizing oil/water emulsions. First, we investigate polymer-coated nanoparticles comprised of oxidized carbon black and covalently grafted amphiphilic polymeric chains. These polymer-coated nanoparticles can be dispersed in the aqueous phase, and when blended with surfactants the nanoparticles migrate to bicontinuous microemulsion phases. The domain size and characteristics of bicontinuous phases are characterized by interfacial tension measurements and small-angle X-ray scattering measurements. Second, we synthesize silica nanoparticles grafted with pH-responsive poly((dimethylamino)ethyl methacrylate) (PDMAEMA) chains. pH-responsive polymeric nanopoarticles can be used to stabilize oil-in-water emulsions under neutral conditions, and at low-pH triggers de-mulsificaiton of heavy oil emulsions. A combination of surface energy and absorbance measurements are used to analyze phase behavior of these emulsions. This work demonstrates the potential of stimuli-responsive polymer-coated nanoparticles for enhanced oil recovery processes.