Fluorine-free superhydrophobic coating with antibiofilm properties based on pickering emulsion templating

This research presents bio-friendly and cost-effective antibiofilm coating formulations based on Pickering emulsion templating. The coating does not contain any active material, where its antibiofilm function is based on passive mechanisms, laying solely on the superhydrophobic nature of the coating, and thus highly suitable for food and medical applications. The coating formulation is based on water in toluene or xylene emulsions that are stabilized by commercial hydrophobic silica, with Polydimethylsiloxane (PDMS) that is dissolved in the organic phase. The stability of the emulsions and their structure were studied by confocal microscopy. The most stable emulsions were applied on polypropylene surfaces and dried in an oven to form PDMS/silica rough coatings. The surface morphology of the coatings shows a honeycomb-like structure that exhibits a combination of micron-scale and nano-scale roughness resulting in a superhydrophobic property. The superhydrophobicity of the resulting coatings has been tuned to meet the demands of highly efficient antibiofilm passive activity. The obtained coatings have shown a decrease of one order of magnitude in the E-coli accumulation on the surface, which is a significant value for coating with a passive-based antibiofilm coating.