Preparation of Golf Ball-like Polymer Particles Bearing Site-Selective Functional Groups

Golf ball-like particles have emerged as interesting materials in the fields of therapeutics, diagnostics, chemical sensing, etc. because of their unique shapes (with concave and convex moieties) and physical properties. Despite their uniqueness, their surfaces are generally covered with single components lacking functional groups, and a well-established functionalization method for a specific area of these particles, such as their concave or convex surface, is lacking. Thus, we proposed a seeded-dispersion polymerization (SDP)-based method for preparing anionic- and cationic-group-bearing golf ball-like polymer particles mainly on their convex surface. Briefly, we prepared golf ball-like particles with site-selective functional groups by subjecting <i>n</i>-butyl methacrylate (<i>n</i>BMA) to SDP in the presence of polystyrene-seed particles and dodecane using 2,2'-azobis(isobutyronitrile) as an initiator; this yielded a poly(<i>n</i>BMA), P<i>n</i>BMA, concave phase. The shape of the golf ball-like particles was also controlled by adjusting the <i>n</i>BMA amount and solvent composition. Further, the results revealed that the functional groups were introduced onto the convex surface of the golf ball-like particles, and the position of the ionic groups on the particles was confirmed based on metal-nanoparticle adsorption. Thus, we demonstrated the feasibility of preparing convex surfaces of golf ball-like particles to impart such surfaces with anionic or cationic functional groups, thereby expanding the application scope of these heteromorphic particles.