Antimicrobial carbon materials incorporating copper nano‐crystallites and their PLA composites

In the first stage, carbon materials were manufactured from chitin and chitosan as the main precursor. Chitin and chitosan were impregnated with Cu²⁺ ions. Using heat treatment, the organic matter (biopolymers) was transformed into a porous carbon matrix, while copper ions were transformed into copper‐based nano‐crystallites containing copper atoms in a +1 and 0 oxidation state. Such synthesized carbons exhibited high contact antifungal activity, e.g., for sample, CH‐ACu0.1_Ox against R. nigricans the inhibition zone is 10.27 mm. In the second stage, composite polymer films were manufactured by mixing polylactide (PLA) and the obtained microbial carbon material (up to 3 wt % Cu‐carbon content). Despite the very low content of carbon material (3 wt %), the composite PLA films exhibited excellent microbial properties for selected bacteria and fungi, e.g., sample CuCM3%/PLA demonstrated high log₁₀ reduction values of 2.17 and 2.66 for the strains of E. coli and S. aureus, respectively. The composite films, and their components, were examined by means of diversified physicochemical methods like low temperature adsorption of nitrogen, SEM, elemental analysis, XRD, cyclic voltammetry, antifungal, and antibacterial analysis. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43429.