The Polymer Society of Korea

Abstract

Organic UV absorbers offer selective and efficient molecular absorbance, particularly in the UVA region, yet their practical use is limited by leaching, poor dispersion stability, and formulation constraints. Here, we introduce a polystyrene (PS) colloid platform that structurally stabilizes absorbance-based UV protection by confining organic UV absorbers within a polymer matrix. PS seed particles are transformed into colloids with tunable internal free volume through controlled swelling and subsequent fixation, enabling post-loading of functional molecules without chemical modification. The hydrophobic UVA absorber DHHB is incorporated into the swollen PS matrix, and the effects of swelling and fixation conditions on loading capacity, dispersion stability, and dissolution behavior are investigated. The resulting PS–DHHB colloids provide UV protection with suppressed leaching and improved colloidal stability in aqueous environments.