Cellulose acetate/silica composites: Physicochemical and biological characterization

Cellulose acetate is of remarkable scientific interest, becoming more useful when is used in obtaining of the composite materials containing nanoparticles, as result of its improved properties. Thus, cellulose acetate/silica composite films obtained by casting the solutions of cellulose acetate (CA)/tetraethyl orthosilicate (TEOS) in different mixing ratios were analyzed in this paper. The impact of TEOS addition, and implicitly of the silica nanoparticles on the mechanical strength, water vapor sorption properties and antimicrobial activity of the cellulose acetate/silica films were mainly monitored. The results of the tensile strength tests were discussed in correlation with data obtained from Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. It was found that samples with low TEOS content show improved mechanical strength compared to samples with high amounts of TEOS. The microstructural characteristics of the studied films affect their moisture sorption capacity so that the weight of the adsorbed water increases with the addition of TEOS. These features are complemented with the antimicrobial activity against Staphylococcus aureus and Escherichia coli bacterial species. The obtained data show that the cellulose acetate/silica films, and especially those with low silica content have improved properties that can recommend them for applications in the biomedical field.