Abstract

The accumulation of plastic waste and infectious diseases has led the scientific community to search for new materials to make nanocomposites biofilms. With the help of nanotechnology, the materials that make up the new nanocomposites biofilm can be manipulated, achieving an improvement in its mechanical properties and granting antimicrobial powers. Biofilms based on electrospun fibers as a barrier material can protect against infectious microorganisms. For these applications, the electrospinning method allows the encapsulation of active agents in the polymeric fibers. This article presents the development of a nanocomposites biofilm with potential use as an antimicrobial barrier, which incorporates polylactic acid microfibers with active agents. Among them, copper ions supported on Chilean natural zeolite nanoparticles and reinforced with acetylated cellulose nanofibers. The study begins with obtaining cellulose nanofibers through mechanical methods. Nanofibers were acetylated to ensure adequate dispersion in the polymer matrix and to improve the mechanical properties of biofilms. Polymers and nanoparticles were incorporated into biofilms through a dual configuration (simultaneous injection) electrospinning stage. Results indicated that acetylated cellulose nanofibers with an average diameter of 83 nm were obtained. The FT-IR characterization confirmed the appearance of bands of adhered acetyl groups in primary hydroxyl groups of the nanocellulose. Morphological analysis of biofilms indicated the presence of continuous, randomly oriented microfibrillar structures and average fiber diameter from 1.7 mu m to 2.4 mu m. According to copper distribution maps, it was confirmed that the electrospinning technique was able to encapsulate nanoparticles of Chilean natural zeolite with copper ions. For all biofilms to which acetylated nanofibers were added, there was an increase in mechanical properties. The thermal degradation profile revealed that the addition of nanoparticles favored the thermal degradation resistance of films. The water vapor permeability test showed that the increased contraction of nanoparticles in the biofilms does not cause an increase in this parameter. The microbiological tests confirmed the biofilms antibacterial activity towards the Gram (-) Salmonella Typhimurium bacteria (responsible for foodborne diseases in poultry products) and Gram (+) Staphylococcus aureus (whose presence accounts for of sanitary and hygienic quality in food processing).