Antibacterial glass films prepared on metal surfaces by sol–gel method

Abstract

This paper describes the preparation and characterization of glass films consisting of SiO2, Li2O, Na2O, K2O or MgO in varying compositions on stainless steel and aluminum substrates by sol–gel method. Silver phosphate or silver incorporated zeolite was also introduced into the sols for obtaining antibacterial effect. The SiO2/Li2O/Na2O system having the composition of 85:5:10 wt% was found as the optimum for obtaining a stable sol and film formation. The films were investigated by scanning electron microscopy (SEM) and electron dispersive analysis by X-ray (EDX), Fourier transformed infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA). Homogenous films having 300 ± 20 nm thicknesses were formed by spin coating and then by curing at 500 °C for 1 h. Obtained films had high adherence to the metal substrates and they were also durable in acidic, basic or NaCl environments. They also presented a powerful antibacterial effect against E. coli.