The use of graphite/TiO2 nanocomposite additive for preparation of polyacrylic based visible-light induced antibacterial and self-cleaning coating

Abstract

Graphite/TiO2 nanocomposite additive was used to make a photocatalytic, hydrophilic, and antibacterial polyacrylic based coating. Various amounts of nanocomposite additive with different weight ratios of graphite to TiO2 were used in a commercial grade polyacrylic matrix and the properties of the related coating were investigated and compared with the polyacrylic coating not containing a nanocomposite additive. FTIR, XRD, FESEM, and UV–Vis spectroscopy were applied to characterize the nanocomposite additive and coating. The water contact angle of additive contained polyacrylic coating reached less than 10° after 24 h illumination of LED lamp light. Photodecolorization efficiency of methylene blue dye aqueous solution in the presence of modified coatings reached 47% during 5 h LED lamp irradiation. The nanocomposite additive formulated coatings exhibited good stability in water environment and antibacterial property against Bacillus anthracis and Staphylococcus aureus Gram positive species. Surfactant presence in the coating formulation and electron–hole pairs produced in graphite/TiO2 nanocomposite additive under LED lamp light prevented the growth of bacterial species. Graphite also adsorbed the bacteria species and kept them in vicinity of antibacterial agents. According to the results, polyacrylic coating containing 3% of graphite/TiO2 nanocomposite additive with graphite to TiO2 weight ratio of 20:100 is proposed as the best coating formulation with the considerable properties between the all of formulations examined in this paper.