Synthesis of thermo- and pH-sensitive polyelectrolyte brushes by combining thermo-controlled emulsion polymerization and photo-emulsion polymerization

Bifunctional spherical polyelectrolyte brushes (SPBs) with tunable thermo- and pH-sensitivity are synthesized by combining thermo-controlled emulsion polymerization and photo-emulsion polymerization. They consist of a spherical polystyrene core and a shell of mixed brushes of poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAA) whose composition can be easily modulated by the dose of monomers. The kinetics of SPB synthesis as well as their size change with temperature and pH is determined by dynamic light scattering (DLS). The scanning electron microscopy (SEM) images show that the bifunctional SPBs have a defined spherical morphology with a narrow size distribution.