Tannin from <i>Schinopsis balansae</i> applied to the nanofunctionalization of protective antifungal coatings

Abstract

Fungal physical, chemical and aesthetical deterioration can occur by microbial biofilms adhere to the surface, leading to alterations on the paints integrity. The sol–gel method affords various merits and added with biocides can be used to control paint films biodeterioration. The aim of the present research was to obtain an efficient antifungal protection to waterborne paint films using a sol–gel coating added with silver nanoparticles synthesized by a green methodology using Schinopsis balansae tannin aqueous solution. Herein, was used a low cost and eco-friendly method for the preparation of silver nanoparticles. The antifungal activity was assessed against Aspergillus niger MN371276, Penicillium commune MN371392, Cladosporium sphaerospermum MN371394 and Lasiodiplodia theobromae MN371283. In addition, the nanofunctionalized antifungal coatings were characterized by SEM micrographs, EDS spectroscopy and mapping, contact angle and determination and absorption/ desorption cycles of humidity. Fungal resistance test of sol–gel coating silver nanoparticles over the paint showed to be efficient to prevent fungal biofilm development with 100% inhibition against all strains tested.