Hybrid nanoparticles by step-growth Sonogashira coupling in disperse systems

Organic/inorganic hybrid nanoparticles were prepared by a Sonogashira miniemulsion polymerization of dibromo aryl and diethynyl aryl monomers and modified titanium dioxide and cadmium selenide nanocrystals, respectively. The poly(arylene ethynylene) microstructure and polymerization rates, as reflected by monomer reactivity, decisively impact whether inorganic guest particles can be trapped to afford a uniform distribution within a newly formed polymer particle or phase separate. This issue was found to be more critical for the TiO2 rods studied here. To this end, the compatibility of the organic and inorganic portions could be improved substantially by the incorporation of functional groups that bind the inorganic surface to the polymer via an appropriate termonomer. This concept, in combination with rapid particle formation via a postpolymerization dispersion of a premade poly(arylene ethynylene)/TiO2 composite as an alternative technique, yielded composite particles with a high loading of the inorganic nanoparticles.