Synthesis of Chitosan–TiO 2 Antimicrobial Composites via a 2-Step Process of Electrospinning and Plasma Sputtering

Electrospun chitosan (Cs) fibers were deposited with titanium dioxide (TiO 2 ) particles through plasma-enhanced chemical vapor process using a compact planar magnetron device. Molecular constructs of Cs and Cs–TiO 2 were modeled using the Gaussian software package to inves-tigate their physicochemical properties and establish the mechanism of interaction between biopolymer and metal oxide. XRD crystalline peak at 25 . 3 ◦ confirmed the integration of TiO 2 into the chitosan fibers. Both experiment and simulation confirmed Cs and TiO 2 combined to become one composite unit Cs–TiO 2 via the glycosidic bond C–O–C of the glucose ring. FTIR and simulated vibrational spectra showed band splittings at 978 and 800 cm − 1 , respectively, which suggests the integration and intermolecular attraction between Cs and TiO 2 at said linkage. SEM shows TiO 2 beads of 100–200nm sizes scattered over the chitosan fibers. The molecular model of Cs–TiO 2 showed optimized geometry withlargerdipolemoment,highernegativeenergy,lowerion-ization potential and narrower HOMO–LUMO energy gap compared to pure Cs; indicative of a resultant composite with enhanced structure and reactivity. Composites synthesized at longer plasma treatment time showed better dispersion of TiO 2 deposits exhibiting higher antimicrobial power with inhibition zones approximately 11.5 mm in diameter.