Antibacterial casein-based ZnO nanocomposite coatings with improved water resistance crafted via double in situ route

摘要

Neat casein film often suffers from poor water resistance and unexpected antibacterial activity. In this study, casein-based ZnO nanocomposite were prepared via double in situ polymerization, where y-(2,3-epoxypropoxy) propytrimethoxysilane (KH560) was used as silane coupling agent. Morphology, structure and size distribution of the composite latexes were characterized by TEM, FTIR, DLS, TG. Meantime, water absorption and antibacterial properties of the as-prepared composite coatings were also investigated. The results indicated that the average size of casein-based ZnO nanocomposite particles was approximately 259 nm. When dosage of ZnO precursor was increased to 3%, water resistance of the composite film was maximized in that water absorption rate was reduced to 49.9%. When dosage of KH560 was 3.5%, the E. coli inhibition zone of casein-based ZnO nanocomposite was expanded from 0 mm to 9.0 mm, suggesting obviously enhanced antibacterial performance than that prepared via single in situ method. The as-prepared composite is a good candidate for functional coatings in relative fields.