A neutron scattering study of the structure of poly(dimethylsiloxane)-stabilized poly(methyl methacrylate) (PDMS–PMMA) latexes in dodecane

Hard sphere particles in nonpolar solvents are an essential tool for colloid scientists. Sterically-stabilized poly(methyl methacrylate) (PMMA) particles have long been used as the exemplary hard sphere system. However, neither the particles themselves nor the poly(12-hydroxystearic acid) (PHSA) stabilizer necessary to prevent aggregation in nonpolar solvents are commercially available. To counter this, several alternatives have been proposed. In recent years there has been an increased interested in polydimethylsiloxane (PDMS) stabilizers as a commercially available alternative to PHSA, yet the structure of particles made in this way are not as well understood as those produced using PHSA. In this work, we employ small angle neutron scattering to determine the internal structure of PDMS-stabilized PMMA particles, synthesized with and without an additional crosslinking agent. We report data consistent with a homogeneous PMMA core with a linearly decaying PDMS shell. The thickness of the shell was in exces...