Mechanical and Antimicrobial Properties of Latex Films Modified with Silver and Hexagonal Boron Nitride Microheterogeneous Powders
Abstract
Natural latex "Revultex LR" was successfully modified with two types of antimicrobial fillers: silver powder and hexagonal boron nitride powder. The resulting composite films exhibited enhanced mechanical properties, excellent dispersion stability, and pronounced antimicrobial activity. Hexagonal boron nitride demonstrated a high specific surface area (27,5 m2/g) and a mesoporous structure --- features that likely promote stronger interactions with the polymer matrix and potentially enhance functional performance. In contrast, silver powder exhibited a low specific surface area (2 m2/g) and was essentially non-porous. Zeta potential measurements of the filler dispersions ranged from --42,6 to --60,5 mV, indicating high electrostatic stability across all modified systems. Fourier-transform infrared (FTIR) spectroscopy revealed no new absorption peaks in the spectra of the composite films, suggesting that the incorporation of fillers did not induce chemical reactions between the powders and the primary components of the latex. The tensile strength of the composite films varied between 19,3 and 35 MPa. Antimicrobial testing showed selective activity: both fillers were most effective against Gram-positive bacteria ("Staphylococcus aureus"), while exhibiting reduced efficacy against Gram-negative bacteria ("Escherichia coli") and yeast-like fungi ("Candida albicans").