Antimicrobial activity from polymeric composites-based polydimethylsiloxane/TiO2/GO: evaluation of filler synthesis and surface morphology

Antimicrobial substances may be used to reduce hospital infections and inhibit food contamination, thus ensuring the safety and well being of humans. The objective of this study was to evaluate the antimicrobial activity of the polymeric nanocomposites polydimethylsiloxane (PDMS) embedded with two types of fillers based on titanium dioxide (commercial TiO 2 P25 versus TiO 2 via facile Microwave-assisted hydrothermal-MAH synthesis) and graphene oxide (GO). The nanocomposites were prepared using different compositions, concentrations, and functionalizations (PDMS/TiO 2 /GO; PDMS/TiO 2 and PDMS/GO). The antimicrobial activity of the samples was evaluated for different treatments on Candida albicans , Staphylococcus aureus, and Enterococcus faecalis, by a modified direct contact test (mDCT). The samples were also evaluated on surface morphology and the roughness as a function of active particles insertion by atomic force microscopy (AFM). Most of the PDMS films whose polymer was embedded with GO and hydrothermal TiO 2 showed the highest inhibition growth of bacteria and Candida over 24 h. After 24 h, F, J, and H samples showed the best antibacterial activity, whereas E showed the best antifungal activity. The results indicated that the nanocomposites PDMS/GO/TiO 2 MAH and PDMS/GO sample enhanced antimicrobial activity in the treatments tested, therefore they were functional for contaminant reduction.