Preparation of Asymmetrically Nanoparticle-Supported, Monodisperse Composite Dumbbells by Protruding a Smooth Polymer Bulge from Rugged Spheres

A novel method is proposed to create asymmetrically nanoparticle-supported, monodisperse composite dumbbells. The method consists of the three steps of double soap-free emulsion polymerizations before and after a heterocoagulation. In the first step, soap-free emulsion polymerization was conducted to cover silica cores with cross-linked poly(methyl methacrylate) (PMMA) shells. Then, positively or negatively charged silica nanoparticles were heterocoagulated with the silica–PMMA core–shell particles. In the heterocoagulations, the nanoparticles surface-modified with a cationic silane coupling agent, 3-aminopropyltriethoxysilane, were used as the positively charged ones, and silica nanoparticles without any treatment were used as the negatively charged ones. In the third step, soap-free polymerizations at different pH values were performed to protrude a polystyrene (PSt) bulge from the core–shell particles supporting the charged silica nanoparticles. In the polymerization, the core–shell particles heterocoagulated with the positively charged silica nanoparticles were aggregated in an acidic condition whereas the silica nanoparticles supported on the core–shell particles were dissolved in a basic condition. For the negatively charged silica nanoparticle, a PSt bulge was successfully protruded from the core–shell particle in acidic and neutral conditions without aggregation of the core–shell particles. The protrusion of the PSt bulge became distinctive when the number of heterocoagulated silica nanoparticles per core–shell particle was increased. Additional heterocoagulation experiments, in which positively or negatively charged magnetite nanoparticles were mixed with the asymmetrically nanoparticle-supported composite dumbbells, confirmed direct exposure of silica nanoparticles to the outer solvent phase

A cumulative effect of risk allele number (<i>C8orf13–BLK</i> rs13277113A and <i>STAT4</i> rs7574865T) on susceptibility to polymyositis, dermatomyositis, and polymyositis/dermatomyositis.

<p>OR: Odds ratio, CI: confidence interval, PM: polymyositis, DM: dermatomyositis, N.S.: not significant.</p

Association between <i>C8orf13–BLK</i> rs13277113 and polymyositis/dermatomyositis.

<p>OR: Odds ratio, CI: confidence interval, PM: polymyositis, DM: dermatomyositis, N.S.: not significant.</p