Frequency and temperature dependent dielectric properties of polyvinyl alcohol/polystyrene sulfonic acid/cobalt oxide nanocomposite films

ABSTRACT

Polyvinyl alcohol (PVA), polystyrene sulfonic acid (PSSA), and cobalt oxide (Co₃O₄) nanoparticles are used in the ease and low-cost solution casting method to prepare flexible nanocomposite films. Structural and morphological studies were carried out for the nanocomposites. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) studies revealed an excellent interaction between the host polymer and Co₃O₄ nanoparticles. Scanning electron microscopy (SEM) was employed to study the surface morphology of the PVA/PSSA/Co₃O₄ nanocomposite films, which exhibited homogeneous dispersion of nanoparticles within the host matrix. Stress–strain curves were obtained to evaluate the mechanical properties of PVA/PSSA/Co₃O₄ nanocomposite films. The dielectric behavior of PVA/PSSA/Co₃O₄ nanocomposite films was examined by varying the content of Co₃O₄ nanoparticles in the frequency and temperature range of 100 Hz–1 MHz and 30–150°C, respectively. The 15 wt% of Co₃O₄ nanoparticles in the PVA/PSSA/Co₃O₄ nanocomposite films have a high dielectric constant (ɛ) of 511.66 and a relatively high dielectric loss (tan δ) of 1440.25 at low frequency and at 60°C, respectively. In addition, the high AC conductivity (σ_ac) obtained for the 15 wt% of Co₃O₄ nanoparticles was found to be 1.66 × 10⁻⁵ Scm⁻¹. The improvement in the dielectric performance of PVA/PSSA/Co₃O₄ nanocomposite films evidenced that they could be promising materials for microwave absorption applications.

Graphical Abstract

KEYWORDS:

• Nanocomposite
• nanofiller
• solution casting
• flexible films
• high dielectric constant
• high dielectric loss

Highlights

1. Fabrication of flexible PVA/PSSA/Co₃O₄ nanocomposite films using solution casting.

2. Functional groups, surface morphology, and structural properties were characterized.

3. Mechanical parameters were evaluated using a stress–strain curve.

4. Dielectric properties of flexible PVA/PSSA/Co₃O₄ nanocomposite films have been investigated.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the RGEMS project [VIT-AP/2021/VC/RGEMS].

Notes on contributors

Y. Ravi Kumar

Y. Ravi Kumar is currently pursuing his Ph.D. from the Department of Physics, School of Advanced Sciences, VIT-AP University, Amaravati, Andhra Pradesh. His research work is based on polymers reinforced with nanofiller for energy storage applications. His M.Phil. degree from the Department of Nanoscience and Nanotechnology, Bharathiar University, Coimbatore. His master’s degree from the National Centre for Nonoscience and Technology, University of Madras, Chennai.

S. K. Khadheer Pasha

Dr. S. K. Khadheer Pasha obtained his M.Sc. degree in Physics from Osmania University, followed by an MPhil degree from Anna University, and Ph.D degree in physics from the Department of Physics, Vellore Institute of Technology (VIT), Vellore-632014, TN, India. He is currently working as a Senior Assistant Professor in the Department of Physics, VIT-AP University. He has about ten years of teaching and 12 years of research experience. His research is mainly focused on the synthesis of nanocomposite materials for various applications such as energy storage, gas sensors, EMI shielding, etc., Currently, he is guiding 5 Ph.D students working on different research topics. He has published over 89 research articles in peer-reviewed international journals and 10 book chapters with RSC, Elsevier, and Springer publishers.