Modified natural mineral with a biogenic compound to control microbial growth in waterborne paint

Abstract

Hygienic paints are designed to control microbial growth by imparting antimicrobial activity both in-film and incan. Biogenic compounds like terpenes in essential oils (EOs) have potential antimicrobial properties. Additionally, modified montmorillonites (Mt) show promise as nanoscale carriers for these compounds. This research aimed to obtain a functionalized antimicrobial montmorillonite hybrid to be applied in the formulation of bioactive paints. The biogenic compounds evaluated were the essential oils of white thyme and mint, to be applied for the first time in hygienic coatings. A soybean derivative was used as an organic modifier of the clay mineral. The synthesized hybrids were characterized by Fourier-Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). Bioassays were carried out against fungal strains including Cladosporium cladosporioides, Chaetomium globosum, and Aspergillus versicolor, as well as bacterial strains such as Staphylococcus aureus and Escherichia coli. White thyme was the EO with the higher antimicrobial activity. Added to this, white thyme oil managed to impart its antimicrobial activity to the synthesized hybrid. The formulated paints with 0.75 concentration of pigment per volume (PVC) efficiently prevented in-can pollution.