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

## TL;DR

This paper introduces a new method to make PVC materials with strong antiviral properties using silver-silica nanoparticles and organic biocides, effective against SARS-CoV-2.

## Contribution

The novel contribution is the development of a hybrid antiviral PVC composite using Ag/SiO2 nanoparticles and organic biocides for enhanced virucidal performance.

## Key findings

- A 2.5 wt% Ag/SiO2 loading inactivated SARS-CoV-2, while only 0.5 wt% of the Ag/SiO2/organic biocide system was sufficient.
- The hybrid system preserved PVC thermal stability and stiffness while limiting discoloration.
- Excessive filler content caused performance drops or cytotoxic effects, highlighting the need for optimized loading.

## Abstract

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.