Optical characterization of PVDF/PMMA/OMMT hybrid polymer nanocomposite films for futuristic optoelectronic devices

Abstract

Hybrid polymer nanocomposite (HPNC) films based on poly(vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA) blend (80/20 wt/wt%) host matrix and organo-modified montmorillonite (OMMT) nanoclay filler (concentrations 0.0, 2.5, 5.0, and 10 wt%) are prepared by the homogenized solution casting method. The X-ray diffraction (XRD) and scanning electron microscopic (SEM) studies revealed the formation of intercalated and exfoliated OMMT structures in the prepared composites. The detailed optical characterization of these HPNC films is carried out with measurements of absorbance spectra by employing a dual beam ultraviolet-visible (UV-Vis) spectrophotometer of wavelength range 200–800 nm. The varying amounts of dispersed OMMT into the PVDF/PMMA blend matrix leads to a gradual decrease in the direct energy band gap of the host matrix from 5.12 eV to 4.54 eV and also shows semiconductive characteristics of 3.83 eV wide band gap at higher nanofiller concentrations. The band gap values of these HPNC films are compared and discussed with other composites of different polymer blend matrices dispersed with a variety of nanofillers. The increase of OMMT concentrations enhanced the range of refractive index (1.85–2.65), extinction coefficient (1.14–10.69 × 10–4), optical range dielectric permittivity (3.44–7.07), and optical conductivity (1.32–17.14 × 1011 s−1) of these HPNC films, at a fixed wavelength of 500 nm, which further changes largely with the alteration in wavelength of incident photons. The nanofiller concentration controllable optical parameters of these PVDF/PMMA/OMMT based HPNCs reveal that they could be promising performance and multipurpose optical materials in the advances of futuristic flexible-type optoelectronic devices.