Control of Particle Size in the Self-Assembly of Amphiphilic Statistical Copolymers

A range of amphiphilic statistical copolymers is synthesized where the hydrophilic component either methacrylic acid (MAA) or 2-(dimethylamino)ethyl methacrylate (DMAEMA) and hydrophobic comprises methyl, ethyl, butyl, hexyl, 2-ethylhexyl methacrylate, which provide a broad partition coefficients (log P). Small-angle X-ray scattering studies confirm that these self-assemble to form well-defined spherical nanoparticles in an aqueous solution, with more forming larger nanoparticles. Varying nature alkyl substituent also influenced self-assembly comonomers producing at given copolymer composition. model based on particle surface charge density (PSC model) used describe relationship between composition nanoparticle size. This assumes monomer preferentially located provides good fit all experimental data. More specifically, linear observed area fraction covered by comonomer required achieve stabilization log P value for comonomer. Contrast variation small-angle neutron study internal structure technique indicates partial phase separation within nanoparticles, about half available repeat units being comonomer-rich cores. information enables refined PSC be developed, same anionic cationic systems. demonstrates how size can readily controlled predicted using relatively ill-defined copolymers, making such systems viable attractive alternative diblock industrial applications.