Novel antibacterial coatings based on chitosan nanocapsules

Chitosan is a cationic polysaccharide with intrinsic antimicrobial properties that can be used as an ecological alternative to develop functional materials to inhibit the proliferation of microorganisms. The new work evaluates chitosan nanocapsules (CNs) as a self-disinfecting agent to provide bactericidal activity on cotton fabrics (CF), using polyacrylate to bind the CNs on the CF surface. The fabrics were characterised by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle (CA), moisture retention, and antimicrobial tests against Escherichia coli and Bacillus subtilis.

Antibacterial activity

The FTIR results showed new peaks related to chitosan structure, indicating the adequate fixation of the CNs on the cotton fibers. SEM images corroborated the polyacrylate binder’s efficient adhesion, connecting the CNs and the cotton fiber surface. The CF surface properties were considerably modified, while CN/polyacrylate coating promoted antibacterial activity against the B. subtilis (gram-positive bacteria) for the developed wipe, but they do not display bactericidal effects against E. coli (gram-negative bacteria).

The study has been published in Journal of Coatings Technology and Research, Volume 20, Issue 5, September 2023.