The structure and fluorescence properties of polypropylene/carbon quantum dot composite fibers

Carbon quantum dot (CQD)/polypropylene (PP) nanocomposite fibers were fabricated using the melt spinning technique. The composite fibers were studied using tensile measurements, wide-angle X-ray diffraction patterns, Fourier transform infrared spectroscopy, fluorescence spectrophotometry, scanning electron microscopy, transmission electron microscopy, and reflection spectrophotometry. The effects of CQDs size, CQD/matrix interface adhesion, and CQD loading on the structure, mechanical, orientation, and optical properties of PP/CQD nanocomposite fibers were investigated using Taguchi experimental design. The produced PP/CQD nanocomposites fibers exhibited color emission under excitation energy, which could be attributed to the presence of CQDs embedded inside the PP matrix. The photoluminescence emission spectra of the nanocomposite fibers containing smaller-size CQD nanoparticles were more significant than other samples at the wavelength of 347 nm. The results of reflection spectrophotometry measurements showed that the purity value was increased with enhancing CQD loading inside the polymer matrix. The results also demonstrated a yellowish red hue imparted to the nanocomposite fibers with improving CQD loading inside the polymer matrix. The amount of redness and yellowness of PP/CQD nanocomposite fibers was lower for the smaller-size nanoparticles and tended to blue and green color. The produced fibers could be easily fabricated and used potentially in a variety of applications like photochemical reactions, anti-counterfeiting, optoelectronic devices, etc.