Optical and structural properties of (PANI-CSA-PMMA)/NiNPs nanocomposites thin films for organic optical filters

Synthesized nanocomposite of protonated polyaniline with camphorsulfonic acid (PANI-CSA) hosted in poly(methyl methacrylate) (PMMA) and incorporated with nickel nanoparticles (NiNPs) were coated as thin films on activated fused silica substrates using oxygen-plasma and spin coating techniques. Weight percent ratios of 0, 10, 20, 30, 60, and 90% of NiNPs with respect to PANI-CSA thin films have been studied in order to investigate the optical, structural, and morphological properties of (PANI-CSA-PMMA)/NiNPs by employing UV-Vis spectrometer, XRD, scanning electron microscopy (SEM), contact angle (CA) goniometry, impedance analyzer, and thermogravimetric analysis. Deduced refractive indices (n) from UV-Vis data were in the range from 1.5 up to 2.2. SEM micrographs show the typical crystalline structure of PANI was vanishing gradually with increasing the NiNPs content. Optical properties such as refractive index (n), extinction coefficient (k), absorption coefficient (alpha) as well as the band-gap energies (E-g) were mathematically deduced throughout the experimental transmittance and absorbance UV-Vis spectra. Calculated refractive indices (n) were in the range from 1.5 up to 2.2. Optical band-gap energies decrease in a monoexponential decay for samples up to 60% NiNPs/PANI-CSA, samples with 90% concentration had substantial drop in its value due to the NiNPs percolations. The incorporation with NiNPs leads to the development of a new morphological states (sheet-like heterostructure) which start to be obvious at 30%, at this concentration the CA was maxima (54 degrees), at this concentration and the crystallite size are maximum and the CA was maximum (highest hydrophobicity). (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48643.