Synthesis of Spherical Polyelectrolyte Brushes by Photoemulsion Polymerization with Different Photoinitiators

Nanosized spherical polyelectrolyte brushes SPBs with tunable size and grafting density were synthesized successfully by photoemulsion polymerization using three photoinitiators. Due to their difference in structure, UV absorption, and mechanism of photoinitiation, the kinetics of photoemulsion polymerization using these respective photoinitiators are different. The grafting densities of poly acrylic acid PAA brushes varied from 0.012 to 0.081 nm 2 by using different photoinitiators, as determined by cutting off the PAA chains from the core particles. All of the spherical PAA brushes prepared by these three photoinitiators are pH and ionic strength sensitive as demonstrated by DLS measurements. Well defined spherical morphology with narrow size distribution for all of the brushes prepared has been observed by FESEM. This work opens a new way to control the synthesis of SPBs with tunable structure for potential applications in catalysis, wastewater treatment, disease diagnosis, and protein immobilizatio