RESUMEN
In recent years, a strong interest has emerged in hybrid composites and their potential uses, especially in chitosan-titanium dioxide (CS-TiO2) composites, which have interesting technological properties and applications. This review describes the reported advantages and limitations of the functionalization of chitosan by adding TiO2 nanoparticles. Their effects on structural, textural, thermal, optical, mechanical, and vapor barrier properties and their biodegradability are also discussed. Evidence shows that the incorporation of TiO2 onto the CS matrix improves all the above properties in a dose-dependent manner. Nonetheless, the CS-TiO2 composite exhibits great potential applications including antimicrobial activity against bacteria and fungi; UV-barrier properties when it is used for packaging and textile purposes; environmental applications for removal of heavy metal ions and degradation of diverse water pollutants; biomedical applications as a wound-healing material, drug delivery system, or by the development of biosensors. Furthermore, no cytotoxic effects of CS-TiO2 have been reported on different cell lines, which supports their use for food and biomedical applications. Moreover, CS-TiO2 has also been used as an anti-corrosive material. However, the development of suitable protocols for CS-TiO2 composite preparation is mandatory for industrial-scale implementation.
RESUMEN
TiO2-ZnO-MgO mixed oxide nanomaterials (MONs) were synthetized via the sol-gel method and characterized by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), nitrogen physisorption analysis, X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Fourier transform infrared spectroscopy (FTIR), and color (Luminosity (L), a, b, Chrome, hue) parameters. Furthermore, the antimicrobial activity of the MONs was tested against Escherichia coli (EC), Salmonella paratyphi (SP), Staphylococcus aureus (SA), and Listeria monocytogenes (LM). The MONs presented a semi globular-ovoid shape of ≤100 nm. Samples were classified as mesoporous materials and preserved in the TiO2 anatase phase, with slight changes in the color parameters of the MONs in comparison with pure TiO2. The MONs exhibited antimicrobial activity, and their effect on the tested bacteria was in the following order: EC > SP > SA > LM. Therefore, MONs could be used as antimicrobial agents for industrial applications.