Abstract
In this study, novel phase-separated composite films based on poly(vinyl alcohol) (PVA) and chitosan lactate (CL) were prepared by the solvent casting method. The influence of varying concentrations of CL (2.5-10% w/w) on the physicochemical properties of the films was assessed. Bright-field micrographs showed the formation of phase-separated polymeric matrices of different architectures in the CL concentration range of 2.5 and 7.5 wt%. At 10 wt% of CL, a homogenous matrix of polymer blend was observed. The developed films demonstrated excellent shielding properties against UV and visible radiation. FTIR studies confirmed the presence of hydrogen bonding between the parent polymers, i.e., PVA and CL, of the films. The film containing 7.5 wt% CL exhibited the highest crystalline nature with little crystal imperfections as compared to the remaining films. Impedance spectroscopy confirmed the conductive nature of the prepared films. The thermograms revealed that the addition of CL strongly influenced the hydrophilic interactions between the functional groups of the polymer components and the water molecules. PVA/CL composite films showed a higher % release of ciprofloxacin HCl (CPH) as compared to the pristine PVA film. CPH-loaded films showed excellent antimicrobial efficacy against model organisms. Therefore, the novel PVA/CL phase-separated composite films can potentially be used as matrices for UV-shielding and drug delivery applications.