Durable antimicrobial finishing of cellulose with QSA silicone by supercritical adsorption

► CO2-philic QAS silicone was synthesized through hydrosilylation and quaternization. ► QAS silicone was coated on cotton by adsorption from scCO2. ► The coating procedure did not need covalently bonding tethering groups. ► The coating provided potent biocidal activities against Staphylococcus aureus and Escherichia coli. ► Antibacterial coating was very stable toward washing and UV irradiation.