Spectral, morphological and optical studies on bischalcone doped polylactic acid (PLA) thin films as luminescent and UV radiation blocking materials

Herein, we report photoluminescence properties by embedding a purely organic fluorophore into a polymer matrix. Biopolymer-polylactic acid [PLA] doped with bischalcone, [1, 3-bis (4-bromobenzylidene) cyclohexan-2-one] is found to show exciting properties for applications in optoelectronics. This paper focuses on the preparation thin films with different dopant concentrations 2%, 4%, 6%, 8% (w/v) dispersed in PLA by solvent casting method. They are characterized by IR, SEM, TGA, DSC and Powder XRD; evidenced the formation matrix-dopant composite films. The UV absorbance of the pristine PLA film is observed at lambda(max) 300 nm and for the doped films at lambda(max) 330 nm. It is observed that as the dopant concentration increased, the intensity of absorbance also increased indicating the UV blocking property of the films with doped bischalcone. The prominent photoluminescence (PL) emission peak at 440 nm is obtained for doped PLA with dopant dependent increase in absolute quantum yield of 41-62%. Thus, the composite material obtained by doping the bischalcone into the polymer matrix is found to block UV radiations and emit light in the visible region, which could make these films versatile materials for optical applications.