Block Copolymer Nanoparticles are Effective Dispersants for Micrometer-Sized Organic Crystalline Particles

Well-defined sterically stabilized diblock copolymer nanoparticles of 29 nm diameter are prepared by RAFT aqueous emulsion polymerization methyl methacrylate using a dithiobenzoate-capped poly(glycerol monomethacrylate) precursor. These evaluated as dispersant for the preparation organic crystalline microparticles via ball milling. This is exemplified azoxystrobin, which broad-spectrum fungicide that widely used to protect various food crops. Laser diffraction and optical microscopy studies indicate formation azoxystrobin approximately 2 μm after milling 10 min at 400 rpm. Nanoparticle adsorption surface these confirmed electron studies. The extent nanoparticle on can be quantified supernatant assay based solution densitometry. technique indicates an adsorbed amount 5.5 mg m–2, sufficient significantly reduce negative zeta potential exhibited azoxystrobin. Moreover, this appears essentially independent nature core-forming block, with similar data being obtained both poly(methyl methacrylate)- poly(2,2,2-trifluoroethyl methacrylate)-based nanoparticles. Finally, X-ray photoelectron spectroscopy confirm attenuation underlying N1s signal arising from former nanoparticles, suggesting fractional coverage 0.24. value consistent theoretical 0.25 calculated isotherm data. Overall, study suggests may offer useful alternative approach traditional soluble dispersants suspension concentrates affecting context agrochemical applications.