Nanoparticle Stability in Polymer Melts As Determined by Particle Second Virial Measurement

Abstract

The stability of 44 nm diameter silica particles in poly(ethylene glycol) (PEG) melts is assessed through the experimental measurement of particle second virial coefficients, B2 = B2,cc/ , where B2,cc is the particle second virial coefficient and is the excluded volume second virial coefficient of the particles. Measurements are made using side bounce ultra-small-angle X-ray scattering (SBUSAXS) of dilute filled PEG melts of variable molecular weight. Results show B2 values to be equal to or greater than one for the molecular weights investigated. Experimental results are compared to recent PRISM theory adaptations to filled polymer melts.