Structural and Optical Properties of Nanofibers Prepared with Electrospinning by Using PMMA Integrated with Curcuminoids to Produce White LED

Abstract

Curcuminoids, a polyphenol from turmeric (Curcuma longa L.) have well-known diverse medical benefits. However, the nature of emitted light from curcuminoids and their poor stability limit their illumination applications but can be further improved using nanofibers and nanoparticles of curcuminoids. In this study, poly(methyl methacrylate) (PMMA) integrated curcuminoid nanofibers (PICNFs) were prepared through electrospinning and characterised. PMMA was mixed with C. longa L. powder to obtain impurity-free curcuminoid solution. Solutions with altering volumes (1, 2, 3, 4 and 5 ml) were spun to grow desired PICNFs. The structural, morphological and optical properties of the as-synthesised PICNFs (with and without annealing) were evaluated as a function of various PMMA concentrations (5, 10 and 15 wt%) to determine the feasibility of improving down-conversion white light emission. The chromatic traits of the proposed PICNFs were analysed under different light-emitting diode LED pumping wavelengths (365, 390 and 445 nm). The chromaticity coordinates (CIE), correlated colour temperature (CCT) and colour rendering index (CRI) of the obtained PICNFs were measured. The FTIR spectra of as-grown PICNFs displayed various characteristic IR bands, which were assigned to the vibrations of different functional groups in the structures. The FESEM images of pre- and post-annealed samples revealed the formation of nanofibers (diameter ranging from 250 nm to 300 nm) and nanoparticles (diameter ranging from 9 nm to 18 nm). The optimum values of CIE, CRI and CCT for the studied PICNFs were (0.3092, 0.315), 76.3 and 6,856 K, respectively.