Abstract
Kevin Mutch: „Colloid-polymer mixtures in the protein limit”
School of Chemistry, University of Bristol, United Kingdom
Colloid-polymer mixtures in the protein limit of large polymer chains and small colloidal particles have been studied by small-angle neutron scattering (SANS). By studying different contrasts, it is possible to extract the individual and cross-term partial structure factors - colloid-colloid (c-c), polymer-polymer (p-p), and colloid-polymer (c-p). The c-c PSF is compared with theoretical predictions, allowing determination of a polymer correlation length. This is compared with a similar correlation length obtained from the p-p PSF, which is shown to increase with colloid concentration. In this sense, adding microemulsion has a similar effect on the dissolved polymer as reducing the solvent quality, and an effective Flory-Huggins parameter has been calculated. The scaling behaviour of these mixtures is also compared with recent predictions by studying systems of varying size ratios.