Production of Uniform Electrospun 2‐Cyanopyridinium Salicylate – Polyvinyl Alcohol Nanofibersusing Cylindrical Bar Collector for Nonlinear Optical Applications

Abstract The electrospinning technique was used to synthesize nanofibers of organic 2‐cynopyridinium salicylate (2‐CPSC) molecules embedded in polyvinyl alcohol (PVA) polymer using both a drum collector and an indigenously made parallel bar cylindrical collector unit. The microscopical analysis was performed for the preliminary morphological study of the collected nanofibers using both a drum collector and a parallel bar collector. Scanning electron microscopic (SEM) analysis confirmed the formation of smooth, clear, cylindrical shape, and highly homogenous 2‐CPSC – PVA nanofibers collected from the parallel bar collector unit compared to the drum collector, and these homogenous nanofibers were selected for further characterization. X‐ray diffraction (XRD) study demonstrates the preferred crystallographic orientation of organic 2‐CPSC molecules inside the host PVA polymer. The synthesized nanofibers were characterized using Fourier Transform Infrared (FTIR) Spectroscopy to confirm the presence of different molecular vibrations. Using ultraviolet‐visible (UV‐Vis) spectroscopic analysis, the complete transparency of the 2‐CPSC – PVA nanofiber throughout the visible region is observed, and from Tauc's plot, the obtained optical band gap energy (E_g) is 5.24 eV. The Z‐scan technique was employed to investigate the nonlinear absorption coefficient (β), nonlinear refractive index (n₂), and third‐order nonlinear susceptibility ( ).