Synthesis of Polyaniline-coated Multi- Walled Carbon Nanotubes/maghemite Nanocomposites and Their Electromagnetic Shielding Properties

Introduction In recent years, the electromagnetic interference (EMI) has been a serious problem because of the proliferation of electronic devices and instruments. EMI can cause the operational malfunction of electric devices leading to loss of valuable time, energy, and resources. It can also cause the human diseases such as leukemia, miscarriages, and breast cancer. So the investigation on the attenuation of EMI has been carried out more deeply by many researchers [1-6]. The metal-based materials have been widely used to reduce EMI. But they have been suffered by the disadvantages of heavy weight and easy corrosion which restrict the wide use of these materials [7]. Carbon nanotubes (CNTs) have been a focus of considerable research since their first observation by Iijima. Their remarkable properties include their interesting mechanical, electrical, thermal, and conductive behavior, and they offer tremendous opportunities for the development of fundamentally new material systems for application in nano scale devices and materials particularly. Similarly, composites based on polymers and CNTs have the potential to make an impact on various applications ranging from general low-cost circuits and displays to power devices, microelectromechanical systems, super capacitors, solar cell sensors, and displays. Despite their appealing properties, the low solubility of CNTs in most organic solvents and their poor compatibility within a polymer matrix make the uniform dispersion of CNTs in the polymer matrix very difficult, limiting their applications. Recent study shows that modifications with the conducting polymers can enhance the sensing properties and dispersion of CNTs. Polyaniline (PANi) has great potential for use in commercial applications because it is cheap to produce, environmentally stable, exhibits enhanced conductivity, and changes its color depending on the redox states. In this study, highly conducting PANi and multi-walled carbon nanotube (MWCNT) nanocomposites were prepared by in situ polymerization for electromagnetic interference shielding. To improve the ferromagnetic properties of the nanocomposite, ferromagnetic materials like γ-Fe2O3 magnetic particles were used together.