Nanostructured transparent superhydrophobic coating for glass and plastic: Study of antimicrobial characteristics

Superhydrophobic coatings have gained substantial attention recently owing to their potential applications in various industries. The adherence of microorganisms to medical equipment can cause infections in the humans and animals. To resist the growth of bacteria, mold, fungus, and other germs on these devices, antimicrobial coatings were prepared. Silica nanoparticles were prepared using the sol gel process and further hydrophobically modified to form transparent antimicrobial coatings on glass and plastic. The size of prepared nano-silica was confirmed through a particle size analyser, which revealed a size of 80.93 nm, and the presence of SiO2 in the prepared sol was indicated by IR spectra. The Zeta potential of the sol was determined to be -40.53 mv, indicating the stability of silica nanoparticles in the solution. The surface morphological studies were conducted by XRD, AFM and SEM which confirmed the uniform distribution of nanostructures on the coated surfaces. The water contact angle on coated glass was found 159.5 degrees and coated plastic having angle of 164.6 degrees which confirmed superhydrophobicity of coating. The antimicrobial activity against E. coli and S. aureus was observed at 1 and 24 h. The results obtained from coated samples showed less bacterial adhesion as compared to uncoated samples. After abrasion test also the superhydrophobicity of coated samples was maintained as the lowest WCA found was 156.4 degrees