Photocontrol of ζ-Potential of Poly(styrene) Microspheres Prepared by Soap-free Emulsion Copolymerization

Exposure to UV light at wavelengths of ≥254 nm caused poly(styrene) microspheres in deionized water to exhibit a negatively shifted (-potential value by generation of carboxyl groups due to photooxidation. Their ζ-potential value could be tuned simply by an exposure dose without a change in their average diameter.