Thermo-mechanical and opto-electrical study of Cr-doped-ZnO-based polyvinyl chloride nanocomposites

Abstract

Polymer nanocomposites exhibit unique physical properties inaccessible from their individual constituents, which are tunable through the type of the polymer matrix, the type and size of the incorporated nanoparticles, and the doping level, and therefore, can be utilized in a wide range of potential applications. Here, we report the fabrication of pure Polyvinyl chloride (PVC) and PVC-based nanocomposites containing different loadings of pure and Cr-doped ZnO nanoparticles, using solvent casting method. Scanning electron microscopy images of the obtained nanocomposite films confirmed the successful incorporation of nanoparticles within the PVC matrix, with higher dispersion quality for the Cr-doped ZnO samples. The prepared nanocomposite samples were found to possess higher thermo-mechanical stability, compared to pure PVC, resulting from the strong interaction between the nanoparticles and polymeric chains, as inferred from their thermogravimetric and dynamic mechanical analysis (TGA and DMA) profiles. Specifically, the temperatures corresponding to the onset and 50% weight loss as well as the glass transition temperature are increased by ~ 88, ~ 34, and ~ 16 °C, respectively, after loading selected amounts of the nanoparticles. In addition to the thermo-mechanical stability, the nanocomposites revealed potentially relevant dielectric response, where the dielectric permittivity exhibits remarkable enhancement, by 400%, compared to pristine PVC. The optical transmission of the PVC is strongly suppressed over the entire visible spectral regime, upon loading the nanoparticles, and its optical band gap (~ 4.1 eV) is red shifted toward the value of pristine ZnO nanoparticles (~ 3.3 eV), while the distinct Cr3+ and Cr6+ optical transitions are preserved for the nanocomposites. The obtained thermo-mechanical stability, required for working devices, together with the here reported improvements in the dielectric response for the nanocomposite samples may alter the typical applications of PVC polymers from being insulating materials to be utilized in energy storage and capacitors manufacture, while the preserved optical properties of the incorporated nanoparticles render these nanocomposites suitable candidates for optoelectronic devices.

Impact of ZnS/Mn on the Structure, Optical, and Electric Properties of PVC Polymer

“…In addition, the absorption band of the doped polymer is redshifted relative to the undoped polymer, and this shift increased as the nanofiller preparation temperature is reduced, as shown in Figure 5a. The PVC loaded with Cr-doped ZnO exhibited a similar feature [12]. In the doped polymers, a new molecular bond between cations and anions may be responsible for this change.…”

“…Tin-doped ZnS@ polyvinyl pyrrolidine polymeric composite films with altered photoluminescent and electrical properties were developed by Badawi et al for use in light-emitting diodes [11]. The preservation of the optical properties of the incorporated nanoparticles makes these nanocomposites promising candidates for optoelectronic devices, and the thermomechanical stability of the Cr-doped ZnO-based PVC nanocomposite samples may alter the traditional roles of PVC polymers from insulators to those of materials for energy storage and capacitors [12]. PVC-doped iodine thin films' optical, chemical, and thermal properties can be modified by incorporating an appropriate concentration of iodine nanofiller into the PVC polymeric matrix [13].…”

A Novel Polyester Varnish Nanocomposites for Electrical Machines with Improved Thermal and Dielectric Properties Using Functionalized TiO2 Nanoparticles

“…The real value of dielectric permittivity is proportional to the number of oriented dipoles present in the tested material and their capacity to undergo orientation at the applied frequency. When the frequency rises, there will not be sufficient time for dipoles to follow the applied field and contribute to the orientation polarization, resulting in a decrease in ε′ rates [57][58][59]. However, the irregular increase in relative permittivity values in the megahertz range is attributed to the possible resonance effects resulting from insufficient contact in the measuring cell [60,61].…”

The Effect of SiO2 Particle Size on Crystallization Behavior and Space Charge Properties for SiO2/MMT/LDPE Composites

“…Over the years, numerous scholars have found that the addition of inorganic particles to composites can effectively increase the breakdown field strength, suppress space charge, and even modulate carrier flow [9][10][11][12][13]. This method of improving certain physical and chemical properties by adding inorganic particles is widely used in industry and engineering.…”