Long-term stability of Ag NPs in a room temperature cured SiO2–ZrO2 crosslinking hybrid robust coating towards enhanced weather resistance properties and its antibacterial applications†

Abstract

SiO₂–ZrO₂ hybrid polymeric network films incorporating silver nanoparticles (Ag NPs) with long-term stability were developed by a sol–gel spray coating technique under room temperature (RT) curing using tetraethyl orthosilicate (TEOS), (3-glycidyloxypropyl)trimethoxysilane (GLYMO), a diamine based curing agent, zirconium(IV) isopropoxide, trimethylsiloxy-terminated polydimethylsiloxane (PDMS) and silver nitrate. Formation of zirconium oxide (ZrO₂) in the Ag NPs embedded polymeric hybrid structure at RT plays a vital role in this robust hybrid matrix to keep Ag NPs stable over a period of 500 days under ambient conditions without significant degradation of absorbance intensity at 415 nm with retention of a strong brownish yellow color. Comprehensive characterization of the RT cured coated film with an Ag NP embedded hybrid matrix was conducted using UV-visible absorption spectroscopy, grazing incidence X-ray diffraction (GIXRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) measurement. The physico-mechanical and weather resistance properties of the prepared zirconia embedded film were evaluated using pencil hardness, adhesion, chemical durability, humidity, thermal effect and UV resistance tests. Due to the long-term stability of Ag NPs in the RT cured hybrid polymeric matrix, it shows potential for antibacterial applications.