Dissolution behavior of Ag-doped antibacterial borosilicate glass powders blended into polypropylene

Silver-doped borosilicate glass powders are frequently embedded into polymer matrices for potential antimicrobial applications. To assess the long-term release kinetics of Ag-containing borosilicate glass powder in polymer matrices, polypropylene (PP) blended with 5 wt% Ag-doped borosilicate glass powders was fabricated via the melt blending process. Additionally, immersion tests were conducted at 60 °C for up to 169 days under both dynamic (water flow rate ∼220 mL/day) and static aqueous conditions. Notably, both boron (B) and sodium (Na) exhibited stable release (0.1–0.4 ppm) over 90 days under dynamic conditions. SEM analysis revealed near-complete dissolution of the glass adjacent to the surface (depth: ∼0.2 mm), while the centrally embedded particles (depth: ∼1.0 mm) remained largely intact. Under static conditions, the concentrations of B and Na increased parabolically up to day 76 and attained kinetic equilibrium by day 103. This was followed by linear increases (∼83.9 ppm B, ∼97.1 ppm Na by day 169), which correlated with the appearance of Na-rich flake-like precipitates. Although the congruent dissolution profiles of B and Na remained similar under both conditions, the slower rate under static conditions was attributed to limited water penetration within the PP matrix.