The swelling of polymeric latex particles with monomers and the partition of slightly water soluble monomers between the particle and aqueous phases are of great importance in understanding the kinetics of emulsion polymerization and particle structure formation. The overall rate of polymerization is directly influenced by the monomer concentration at the loci of chain propagation reaction (latex particle, monomer droplet, or aqueous phase). In addition, initiator efficiency, rates of radical transfer, and copolymer or graft composition (in multistage reactions) also depend on monomer concentration and partition.
W.-D. Hergeth and P. J. Codella, "Monomers in Polymer Dispersions. Part IV: Partition of Acrylonitrile in Rubber Latex as Studied by Raman Spectroscopy," Appl. Spectrosc. 48, 900-903 (1994)