Hybrid Silver–Silica and Organic Biocide Systems in PVC: Enhanced Antiviral Performance against SARS-CoV-2

Poly(vinyl chloride) (PVC) is widely used in biomedical devices and hospital infrastructure. In light of emerging pathogens such as SARS-CoV-2, there is a growing need for PVC materials with intrinsic antiviral properties. This study presents an effective strategy to develop antiviral PVC nanocomposites by incorporating silver-silica (Ag/SiO₂) hybrid nanoparticles via melt processing. Two hybrid nanoparticle systems were incorporated: SiO₂ decorated with silver nanoparticles and a mixture of Ag/SiO₂ with two organic biocides (triclosan and zinc pyrithione). Comprehensive morphological, optical, thermal, and mechanical characterizations were conducted to assess structure-property relationships, along with antiviral tests against SARS-CoV-2. The addition of Ag/SiO₂ nanoparticles preserved the PVC thermal stability and impact strength, whereas it increased the stiffness. The particles containing the biocides limited PVC discoloration but affected the mechanical properties due to their plasticizing effect. Whereas a concentration of 2.5 wt % of Ag/SiO₂ nanoparticles inactivated SARS-CoV-2, only 0.5 wt % of the Ag/SiO₂/organic biocide system was necessary, showing a combined virucidal response between Ag on the nanocomposite surface and triclosan that is released. Excessive filler content led to performance drops or cytotoxic effects. The combination of inorganic and organic antimicrobial agents enables tailored functionality, demonstrating the potential of these materials for use in medical devices, personal protective equipment, and surfaces requiring antimicrobial protection.