Preparation and characterization of cotton fabrics with antimicrobial properties through the application of chitosan/silver-zeolite film

The development of antimicrobial cotton fabrics using chitosan/silver-zeolite film has been investigated in the present work. The film was applied to 100% cotton fabric using a common pad-dry-cure technique and citric acid was used as crosslinking agent. The resulting fabrics were characterized through infrared spectroscopy (FTIR), contact angle and scanning electron microscopy with X-ray microanalysis (SEM/EDS). The antimicrobial activity of the fabrics was assessed through the viable-cell counting method and the materials showed activity against S. aureus and T. rubrum. The textile performance of the fabrics was analysed regarding their characteristics of hydrophilicity and breathability. The finishing did not change the hydrophilic behaviour of the material. Although the permeability to air has reduced 20%, the permeability to water vapour remained practically unchanged. Therefore, the results suggested that the process approach of applying chitosan/silver-zeolite film is recommended to produce textiles with antibacterial properties.CNPq-Brazil (Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brazil/National Council of Scientific and Technological Development – Brazil) for the doctoral scholarship (233550/2014-3). This work is also financed by FEDER funds through the Competitivity Factors Operational Programme – COMPETE and by national funds through FCT – Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007136. This research was partially supported by the Strategic Funding UID/Multi/04423/2013 through national funds provided by FCT - Foundation for Science and Technology and European Regional Development Fund (ERDF), in the framework of the program PT2020.info:eu-repo/semantics/publishedVersio

Chemical characterization and thermal comfort properties of cotton finished with phase change materials and antimicrobial agents

The expectations regarding the functional characteristics and performance of textile products have been steadily increasing. In this sense, multifunctional materials with thermoregulatory and antimicrobial properties were developed using different finishing strategies. For this purpose, through finishing processes, the application of microcapsules of phase change materials, mPCM, combined with different antimicrobial agents of natural origin, was carried out. Specifically, zeolites doped with silver, composites of chitosan with zeolites doped with silver, and TiO2, in different application combinations, were used. The resulting multifunctional cotton materials were characterized and their performance was evaluated in terms of thermal comfort, stationary properties and moisture management. The statistical analysis of the results has indicated that the thermal properties underwent changes related to the introduction of mPCM in the treated samples, but the antimicrobial finishing also had an effect on the results obtained. As expected, the finishes contributed to a decrease in the permeability of the samples studied, however, without compromising the breathability of the materials. It was concluded that the best combination of finishes was achieved with the application of mPCM combined with the chitosan film with silver doped zeolites.- The authors acknowledge CNPq-Brazil (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico Brasil/National Council of Scientific and Technological Development - Brazil) for the doctoral scholarship (233550/2014-3). This work has been also financed by Project UID/CTM/00264/2019 of 2C2T - Centro de Ciencia e Tecnologia Textil, funded by National Founds through FCT/MCTES

Antimicrobial properties of composites of chitosan-silver doped zeolites

The antimicrobial functionality of composites constituted by chitosan with silver-doped zeolites was developed and characterized. A composite with chitosan particles and silver-doped zeolites was synthesized using an ionic gelation process with sodium tripolyphosphate. The chitosan silver-doped zeolites composite obtained presented sizes up to 5 mu m, while the silver-doped zeolites had an average size between 0.5 mu m and 3.3 mu m. The synthesized chitosan silver-doped zeolites composites, as well as the silver-doped zeolites and the chitosan dissolution, were characterized through X-ray diffraction, Fourier Transform Infrared spectroscopy and scanning electron microscopy. The electro kinetic behaviour of chitosan, silver-doped zeolites and chitosan silver-doped zeolites composite was evaluated under different pH conditions. The antimicrobial activity of the composites was evaluated in terms of minimum inhibitory concentrations and minimum lethal concentrations and the results suggest that the chitosan silver-doped zeolites composites show antimicrobial activity against gram-negative and gram-positive bacteria, Escherichia coli and Staphylococcus aureus, respectively and against Candida albicans. The results here presented support the potential application of the composite of chitosan with silver-doped zeolites in the functionalization of textiles with antimicrobial properties.- Fabio A. P. Scacchetti thanks to the CNPq-Brazil (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-Brasil/National Council of Scientific and Technological Development-Brazil) for the doctoral scholarship (233550/2014-3). Artur Ribeiro and Artur Cavaco-Paulo thanks to the Portuguese Foundation for Science and Technology (FCT) for the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norte. This work is also financed by Project UID/CTM/00264/2019 of 2C2T-Centro de Ciencia e Tecnologia Textil, funded by National Founds through FCT/MCTES