A green formulation for superhydrophobic coatings based on Pickering emulsion templating for anti-biofilm applications

Raz Cohen; Karthik Ananth Mani; Madina Pirmatova; Gila Jacobi; Einat Zelinger; Eduard Belausov; Elazar Fallik; Ehud Banin; Guy Mechrez

doi:10.1016/j.colsurfb.2023.113355

A green formulation for superhydrophobic coatings based on Pickering emulsion templating for anti-biofilm applications

Colloids Surf B Biointerfaces. 2023 Jul:227:113355. doi: 10.1016/j.colsurfb.2023.113355. Epub 2023 May 18.

Authors

Raz Cohen¹, Karthik Ananth Mani², Madina Pirmatova¹, Gila Jacobi³, Einat Zelinger⁴, Eduard Belausov⁵, Elazar Fallik⁶, Ehud Banin³, Guy Mechrez⁷

Affiliations

¹ Department of Food Sciences, Institute of Postharvest and Food Sciences, Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion 7505101, Israel; The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, POB 12, Rehovot 7610001, Israel.
² Department of Food Sciences, Institute of Postharvest and Food Sciences, Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion 7505101, Israel.
³ The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 5290002, Israel.
⁴ The Interdepartmental Unit, Microscopy Lab, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel.
⁵ Department of Ornamental Plants and Agricultural Biotechnology, Institute of Plant Sciences, Agricultural Research Organization (ARO), Volcani Center, Rishon Letzion 7505101, Israel.
⁶ Department of Postharvest Science, Agricultural Research Organization, The Volcani Institute, Rishon Lezion, 7505101, Israel.
⁷ Department of Food Sciences, Institute of Postharvest and Food Sciences, Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion 7505101, Israel. Electronic address: guyme@volcani.agri.gov.il.

PMID: 37216726
DOI: 10.1016/j.colsurfb.2023.113355

Abstract

This study reports significant steps toward developing anti-biofilm surfaces based on superhydrophobic properties that meet the complex demands of today's food and medical regulations. It presents inverse Pickering emulsions of water in dimethyl carbonate (DMC) stabilized by hydrophobic silica (R202) as a possible food-grade coating formulation and describes its significant passive anti-biofilm properties. The final coatings are formed by applying the emulsions on the target surface, followed by evaporation to form a rough layer. Analysis shows that the final coatings exhibited a Contact Angle (CA) of up to 155° and a Roll-off Angle (RA) lower than 1° on the polypropylene (PP) surface, along with a relatively high light transition. Dissolving polycaprolactone (PCL) into the continuous phase enhanced the average CA and coating uniformity but hindered the anti-biofilm activity and light transmission. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed a uniform coating by a "Swiss-cheese" like structure with high nanoscale and microscale roughness. Biofilm experiments confirm the coating's anti-biofilm abilities that led to the reduction in survival rates of S.aureus and E.coli, by 90-95% respectively, compared to uncoated PP surfaces.

Keywords: Antibiofilm; Coatings; Dimethyl carbonate; Pickering Emulsion; Super hydrophobic.

MeSH terms

Biofilms*
Emulsions / chemistry
Hydrophobic and Hydrophilic Interactions
Staphylococcus aureus*
Water

Substances

Emulsions
Water