Search

This study reports on the electrical conductivity, dielectric, and electromagnetic interferenc (EMI) shielding properties of conductive epoxy/PAni blend containing various concentrations. Polyaniline (PAni) was synthesized using oxidative chemical polymerization technique and then dispersed into epoxy resin using a sonication bath. Infrared spectra confirm the curing of composites. Increasing the aspect ratio of PAni in epoxy increased the electrical conductivity and improves the microwave absorption properties of composites in the microwave range (0.1 GHz–20 GHz). Electrical conductivity was measured by using the four-probe method, and the maximum conductivity of the composite was achieved 3.51 × 10−13 Scm−1 with 30 wt% of PAni. The maximum porosity of the composite with 30 wt% of PAni was 15.5%. EMI shielding was measured by a vector network analyzer (VNA) in the microwave region (0.1 GHz–20 GHz), which gives the maximum value of 63 dB. IR shielding was measured by IR spectroscopy and less than 0.5% transmission was observed in NIR (700 nm–2500 nm) region. The average particle size of PAni is found to be 113 nm. These composites were used as a potential candidate for conductive coatings, EMI shielding purposes, and electronic applications.

Based on recent advancements, the emission of electromagnetic radiation has become a serious issue of electromagnetic interferences. These electromagnetic interferences comprise of various undesirable emission of radiation that can create unwanted deprivation of equipment or structure performance. If these complications remain unresolved can create extreme damage to the security operation or communication system of several electronic devices. Various studies have been made to resolve these problems. In past years, electrically conductive polyaniline has attained a unique position due to the prosperity of its features. The absorption of microwave and EMI shielding characteristics of the electrically conductive polyaniline can be described in the relation of great electrical conductivity with strong relaxation and, polarization effects due to the existence of stronger bonds or localized charges. In the present article, the advancement in electromagnetic interference shielding with the use of nanosized polyaniline particles and their derivative nanocomposites is discussed by various parameters such as the size of the particle, absorption properties, magnetic properties, reflective properties, electrical conductivities, and dielectric properties. The electromagnetic absorption performance of conducting polyaniline nanocomposites associated with dielectric nanomaterials (graphene) and magnetic materials (γ-Fe2O3) are widely discussed. The most appropriate polyaniline-based nanocomposites can be identified by this context. Due to increasing demand of electrically conductive polyaniline for shielding materials, it is considered to be review for better understanding in advancement. This article presents recent electromagnetic interference shielding materials knowledge of nanosized polyaniline and their nanocomposites as well as their possibilities and challenges.

The co-precipitation and in situ modified Hummers’ method was used to synthesize Nickel Spinal Ferrites (NiFe) nanoparticles and NiFe coated with Thermally Reduced Graphene Oxide (TRGO) (NiFe-TRGO) nanoparticles, respectively. By using polyvinyl chloride (PVC), tetrahydrofuran (THF), and NiFe-TRGO, the nanocomposite film was synthesized using the solution casting technique with a thickness of 0.12–0.13 mm. Improved electromagnetic interference shielding efficiency was obtained in the 0.1–20 GHz frequency range. The initial assessment was done through XRD for the confirmation of the successful fabrication of nanoparticles and DC conductivity. The microstructure was analyzed with scanning electron microscopy. The EMI shielding was observed by incorporating a filler amount varying from 5 wt.% to 40 wt.% in three different frequency regions: microwave region (0.1 to 20 GHz), near-infrared (NIR) (700–2500 nm), and ultraviolet (UV) (200–400 nm). A maximum attenuation of 65 dB was observed with a 40% concentration of NiFe-TRGO in nanocomposite film.

In this study, cellulose acetate (CA) was blended with sulfonated graphene oxide (SGO) nanomaterials to endow a nanocomposite membrane for wastewater treatment with improved hydrophilicity and anti-biofouling behavior. The phase inversion method was employed for membrane fabrication using tetrahydrofuran (THF) as the solvent. The characteristics of CA-SGO-doped membranes were investigated through thermal analysis, contact angle, SEM, FTIR, and anti-biofouling property. Results indicated that anti-biofouling property and hydrophilicity of CA-SGO nanocomposite membranes were enhanced with addition of hydrophilic SGO nanomaterials in comparison to pristine CA membrane. FTIR analysis confirmed the successful decoration of SGO groups on CA membrane surface while revealing its morphological properties through SEM analysis. Thermal analysis performed using DSC confirmed the increase in thermal stability of CA-SGO membranes with addition of SGO content than pure CA membrane.

Polymer blends of polyaniline (PANI) and polyvinyl chloride (PVC) were fabricated using thermally reduced graphene oxide (TRGO) as nano-level reinforcement to enhance the electromagnetic interference (EMI) shielding effectiveness. The initial assessment of polymer blends of PVC and PANI and hybrid nanocomposites of PVC, PANI and TRGO were done with cyclic voltammetry and the results showed improved electrical conductivity of 1.0 × 10−15 S/cm, 1.5 × 10−6 S/cm and 4.2 × 10−5 S/cm respectively. The capacitive effect of this blend and hybrid nanocomposites were evaluated as an initial assessment at frequency region (100 Hz–5 MHz). EMI-shielding effectiveness of PVC, PVC/PANI blend and PVC/PANI/TRGO hybrid nanocomposites were measured in the microwave frequency region of 11–20 GHz. Almost 29 dB shielding effectiveness was observed in case of PVC–PANI blend. The shielding effectiveness was enhanced to ~ 56 dB as 5 wt% of TRGO was added. The dispersion state, interaction of filler with the polymer matrix and the nature of fillers are the main reasons to the enhance EMI shielding of these hybrid nanocomposites.