Fabrication of Glycine-Chitosan/TiO2 film for metanil yellow removal from water

Abstract

This study focused on the modification of chitosan with glycine and TiO2 to improve its performance for adsorption application. It is the first study to use a combination of chitosan, glycine, and TiO2 in the preparation of composite films. The obtained chitosan-glycine/TiO2 composite films were extensively characterized using various techniques, including FT-IR, SEM, XRD, DSC, and tensile tests to study the functional groups, morphology, structure, thermal stability, and mechanical properties of composite films, respectively. FT-IR analysis confirmed the successful formation of the chitosan-glycine/TiO2 film, where chemical interaction occurred between the carboxyl groups of glycine and NH2 of chitosan through a condensation process and physical interaction occurred between chitosan-glycine and TiO2. SEM images revealed that the surface of chitosan-glycine/TiO2 composite films exhibited a rougher texture compared to the unmodified chitosan, indicating structural changes due to the addition of glycine and TiO2. XRD analysis indicated alterations in the crystallinity properties of chitosan upon the incorporation of glycine and TiO2. The DSC results demonstrated that the presence of glycine and TiO2 influences the thermal stability of chitosan. The tensile test revealed the improvement of tensile strength in the chitosan-glycine/TiO2 film, related to the existence of glycine and TiO2. The adsorption process of metanil yellow by the chitosan-glycine/TiO2 film was in accordance with the Langmuir isotherm model. In conclusion, the modification of chitosan with glycine and TiO2 resulted in the development of a promising adsorbent material with improved thermal stability, enhanced tensile strength, and a higher adsorption capacity for metanil yellow. These findings contribute to the potential application of chitosan-glycine/TiO2 films in various adsorption processes.