Core-shell particles synthesized through controlled free radical polymerization

A process for producing a core-shell polymer that comprises:

• (1) preparing a monomer solution which is comprised of (a) a first monomer, (b) a conjugate acid of a surfactant with a pKa of less than 14, and (c) a controlled free radical polymerization agent;
• (2) preparing an aqueous medium which is comprised of (a) water, and (b) a conjugate base of a weak acid wherein the pKb of the base is less than 14;
• and (3) mixing the monomer solution with the aqueous medium under conditions that result in the in-situ formation of an emulsifier to produce a polymerization medium, (4) initiating free radical polymerization within the polymerization medium in the presence of a free radical control agents to produce a solution of polymeric particles, (5) adding a second monomer to the solution of polymeric particles, and (6) allowing polymerization to proceed in the presence of the free radical control agent to produce the polymer, wherein the core-shell polymer includes a core which is comprised of repeat units of the first monomer and a shell which is comprised of repeat units of the second monomer, wherein the core is at least partially engulfed by the shell, and wherein the core is incompatible with the shell.