EVALUATION OF ANTIBACTERIAL AND STRUCTURAL PROPERTIES OF COTTON FABRIC COATED BY CHITOSAN/TITANIA AND CHITOSAN/SILICA HYBRID SOL-GEL COATINGS

Coatings of chitosan with both of titania and/or silica at different ratios were prepared and applied to the cotton fabric. The antibacterial activity of the samples were evaluated quantitatively according to the modified procedure of the shake flask method (ASTM E2149-01). It was found that there was a corresponding relation between the media and the activity of titania coatings. To the experimental results, all the samples coated by titania have shown perfect activity after 5 hour irradiation under UV light. On the other hand, their activity values were found to be less than the other samples under dark media conditions. The combination of titania and chitosan solutions was found to be more favourable than only chitosan coating. In addition to this, it's seen that the combination of silica and chitosan sols was more effective than application of chitosan or silica sol alone. After washing process, the combined systems showed the best results. The structure of cotton fabric and its morphology were studied using SEM-EDX, X-ray diffraction and FT-IR analysis. From the SEM images, it's observed that there is a compatible bonding with cotton fiber and combined coatings and this fact ensures the washing durability. The EDX results has confirmed the presence of titania and silica in the coatings. To the X-ray analysis, no significant difference was observed among the processes showing the stability of the crystallinity of the samples.