Chitosan-graft-Poly(trichlorovinylsilane) Polymers: Synthesis, Characterization, Antibacterial Susceptibility and Dye Adsorption Studies

In this study, chitosan-grafted-trichlorovinylsilane (CT–g–VTCS) film is produced and elucidated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy dispersive X-ray (EDX). The SEM micrograph of exhibited refine structure with rough surface. The CT–g– VTCS antibacterial action was assayed using the agar diffusion and broth dilution approach. Obtained results herein pointed out that CT–g–VTCS exhibited increased water solubility (67 mg/mL) when compared with chitosan (CT) film (2.6 mg/mL). CT–g–VTCS exhibited improved antibacterial action against S. aureus, E. coli, Kleb spp., E. faecalis and Methicillin-resistant Staphylococcus aureus (MRSA) (minimum inhibitory concentration (MIC) = 0.078 – 0.156 mg/mL and minimum bactericidal concentration (MBC) = 12.5 – 3.12 mg/mL) higher than the precursor CT film. Contrary to most quaternized chitosan derivatives, the CT–g–VTCS was processed via a simple and easy route and showed comparatively high antibacterial efficiency. Studies from the time-kill assessment revealed that 5 mg/mL CT–g–VTCS exposed to the bacteria cells is copious to give a ~0.08 log10 reduction (>99.9% kill rate) within 24 h. Vinyltrichlorosilanechitosan-graft-polyacrylamide (VCSCT-g-PAAm) hydrogel was also synthesized. From the results obtained, hydrogels with varying molar ratios of VCSCT-g-PAAm all formed within 13 min. The incorporation of polyacrylamide onto vinyltricholosilane–chitosan backbone enhanced the hydrogel physical and chemical properties in terms of strength, swelling capacity, adsorptivity and antimicrobial activity. The VCSCT-g-PAAm hydrogel interacted with methylene blue (MB) dye solution at different mass-liquid ratio, pH and temperature. The amount of MB dye removal was estimated using UV-Vis spectrophotometer at an optical density of λmax= 665nm. The MB dye removal was most effective at pH 12 with about 98% removal at 50oC. The hydrogel was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and other physicochemical parameters. Experimental data obtained for the adsorbent-MB dye pair suited the Langmuir, Freundlich and pH-dependent Langmiur Freundlich adsorption isotherms. Calculated values for ∆Ho , ∆So , ∆Go were - 2.72kJ/mol, 16.72J/mol K and 7.73kJ/mol correspondingly. Further studies revealed high swelling ratio in basic solution with about 1,179% swellability. Investigations showed that VCSCT-g-PAAm hydrogel exhibited a high percentage killing against S. aureus and E. coli, more than 99.9% kill rate after 24 hr contact with S.aureus and E.coli, this can contribute immensely in biomedical application and beneficial in waste water treatment. Keywords: Chitosan, Trichlorovinylsilane, Antibacterial, Adsorption, Methylene blue.