Dielectric Analyzer Research Articles

Synthesis, growth and nonlinear optical properties of imidazolium hydrogen adipate monohydrate single crystal

A single crystal of Imidazolium Hydrogen Adipate Monohydrate (IHAM) has been obtained by the slow evaporation technique. The grown crystal belongs to the Triclinic crystal system. The spectral studies were further used to confirm the structure. The Hirshfeld analysis suggests that the major bonding in the crystal occurs through the Hydrogen atom constituting 69 % of the total bonding. The Void analysis shows a lower percentage of voids suggesting that the crystal is strongly packed. The optical constants such as optical and electrical conductivity, optical susceptibility and extinction coefficient were elucidated from the UV–Vis-NIR analysis. The refractive index of IHAM was determined to be 1.391 by the Prism Coupler. The work-hardening coefficient of the title compound was found to be 1.14 which classifies the material as hard. The hardness number shows the normal Indentation Size Effect (ISE). The electrical characteristics were studied by using the dielectric analyser. The solid-state parameters such as the Fermi gap, Penn gap and optical electronegativity were calculated based on the dielectric parameters. The electronic polarizability calculated by different methods is in mutual agreement. The TG/DTA analysis suggests that the material is suitable for applications up to 79 °C. The Z-Scan analysis confirms the Reverse Saturable Absorption behaviour. The third-order nonlinear susceptibility was calculated as 9.77×10−9 esu.

Tailored Ni‐Zn‐Cu ferrite/EPDM nanocomposites: Synthesis, characterization, and multifaceted properties for mechanical and electrical applications

AbstractIn this study, we prepared Ni‐Zn‐Cu Fe2O4 ferrite/ethylene propylene diene monomer (EPDM) rubber nanocomposites with enhanced mechanical and electrical properties. First, Ni‐Zn‐Cu Fe2O4 ferrite nanoparticles were synthesized with a tailored composition of NiZn(0.3)Cu(0.2)Fe2O4(2). Subsequently, these nanoparticles were incorporated into the EPDM rubber matrix through a two‐roll mixing mill. Scanning electron microscopy and x‐rays diffraction techniques were used to explore their morphology and structure. Fourier‐transform infrared spectroscopy was used to identify metal‐oxygen bonds in the nanoparticles and their incorporation in the nanocomposites. Similarly, curing properties, including optimum cure time, scorch time, and torque profiles, were evaluated using a moving die rheometer. While, mechanical properties of these composites, such as tensile strength and Young's modulus, were determined with a universal testing machine. Tensile strength improved from 0.11 MPa to 0.22 MPa (100% increase), whereas, the Young's modulus increased from 0.03 MPa to 0.052 MPa (86% increase). Additionally, we investigated the dielectric properties of these nanocomposites, encompassing permittivity, resistivity, and dielectric constant, using a dielectric properties analyzer. Our findings revealed a significant reduction in dielectric resistivity of nanocomposites (from 33.2 GΩ to 23.38 GΩ) upon the introduction of Ni‐Zn‐Cu Fe2O4 ferrite nanoparticles, indicating the formation of a continuous nanofiller network within the EPDM matrix. Interestingly, as the nanofiller loading increased, both dielectric permittivity and dielectric constant exhibited a gradual rise. The permittivity value increased from 2.31 to 2.39 (Fm−1), while the dielectric constant increased from 0.0091 to 0.0179.Highlights Synthesized Ni‐Zn‐Cu Fe2O4; tuned composition NiZn(0.3)Cu(0.2)Fe2O4(2). Integrated ferrite into EPDM; optimized mixing for enhanced properties. Employed SEM, XRD, and FTIR; revealed morphology, structure, and bonding. Evaluated curing using MDR; unveiled optimal time and torque profiles. Explored dielectric properties; demonstrated reduced resistivity, heightened permittivity.

Rare earth Gd3+ substituted on cobalt ferrites: Structural and dielectric studies by citrate gel autocombustion method

Gadolinium-doped cobalt ferrite (CoGdxFe2-xO4; X = 0–0.025 in a 0.005 interval) was synthesised using citrate gel autocombustion. The effect of Gd3+ ions on structural, dielectric, and magnetic characteristics has been investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, ultraviolet visible spectroscopy (UV), an impedance (dielectric) analyzer, and a vibrating sample magnetometer (VSM) were used to characterise the as-synthesised materials. X-ray diffraction powder patterns were used to confirm phase identification and spinel structure, and the Williamson-Hall plot was used to investigate the crystalline size and lattice strain on the peak broadening of each sample, with crystalline size ranging from 13 to 48 nm. The scanning electron microscopy (SEM) micrographs demonstrate particle agglomeration, while energy dispersive spectroscopy (EDAX) pictures indicate the purity and existence of all elements in the created material samples. The frequency-dependent dielectric constant, dielectric loss, and AC electrical conductivity in the frequency range 50 Hz–1 MHz. The behaviour of dielectric properties has been studied using the Maxwell-Wagner model and Koop's theory. Because of this, higher frequencies show less dielectric loss, making them appropriate for use in high-frequency device applications.

Experimental Investigation of the Effect of Transient Overvoltages on XLPE-Insulated HVDC Cables

HVDC cables are subject to several types of impulses superimposed on the rated DC voltage during their service lifetime. Temporary Overvoltages (TOVs) and Superimposed Switching impulses (SSIs) are considered some of the most challenging due to the relatively long impulse duration. This paper aims at investigating experimentally the effect of TOVs and SSIs on XLPE insulation for extruded HVDC cables. 0.15-mm-thick DC-XLPE specimens, aged by applying TOVs and SSIs, are characterized using dielectric analyzer and Fourier Transform InfraRed spectroscopy (FTIR) to detect the aging effects on the insulation. Results show an increase in the imaginary part of permittivity, ε", accompanied with the appearance of additional dipolar polarization losses peaks. The amplitude and frequency of the aforementioned peaks vary with the amplitude and the number of applied TOVs and SSIs. An increase in electrical conductivity is also noticed with aging. FTIR results show absorbance peaks in the aged specimens likely due to the intramolecular bonds rupture accompanied with the formation of aging products. In summary, SSIs and TOVs cause a noticeable reduction of insulating properties in XLPE specimens. The higher the peak of the transient, the greater the aging effect.

Investigation of the Structural Dependence of the Cyclical Thermal Aging of Low-Voltage PVC-Insulated Cables

The increasing penetration of distributed generation sources in low-voltage distribution grids, electric vehicles, and new appliances from the consumer side can generate short repetitive overloads on the low-voltage cable network. This work investigates the change in the dielectric properties of low-voltage cable insulation caused by short-term overloads, examining how the cable structure affects the dielectric characteristics of the cable specimens in the case of cyclic short-term thermal aging. PVC-insulated low-voltage cable samples were exposed to an accelerated aging test in a temperature-controlled oven after changing their structures by removing different layers. Three aging cycles, each of six hours, were applied to the samples. After each cycle, the tan δ and capacitance were measured by an Omicron DIRANA Dielectric Response Analyzer in the laboratory at room temperature 24 ± 0.5 °C. Furthermore, the polarization and depolarization currents were also studied. The results show that changing the cable structure impacts the dielectric parameters; in particular, the effect of the belting layer is significant. From the point of view of aging, the PVC belting layer protects the diffusion of the plasticizers of the inner structure. The findings of the study show that an asymmetric aging phenomenon can be observed in different polymeric components of the cables, even though the cables were aged in an air-circulated oven ensuring a homogeneous temperature distribution in the samples.

Research on triazine reaction, heat resistant and dielectric properties of cyanate ester resin catalyzed by bisphenol AF

Cyanate ester (CE) resins possess a wide variety of attractive features that make them suitable for both electronic and aerospace composite applications. However, high curing temperature and long curing time limit the application range of CE resins. In this study, curing reaction, heat resistant and dielectric properties of bisphenol A-based cyanate ester (BACY) resin catalyzed by bisphenol AF (BPAF) were investigated by means of differential scanning calorimetry, Fourier transform infrared, dynamic mechanical analyser and dielectric properties analyser. The incorporation of the BPAF decreased the curing temperature and showed a strong catalytic effect in cyclotrimerization reaction of BACY. BACY resin catalyzed by 4 phr BPAF at 180 °C post-cured for 5 h presented high curing degree of 92.8% and glass transition temperature of 247.4 °C. Moreover, BACY resin catalyzed by 4 phr BPAF at 180 °C post-cured for 5 h exhibited excellent dielectric properties (ε and tan δ equal to 2.87 and 0.0084) comparable to commercial modified cyanate ester resin post-cured at 200 °C for 10 h. These results suggest that catalyst BPAF possesses promising potential application in meeting low-temperature short-term curing of high-performance cyanate ester resin based wave-transparent composites.

The impact of V2O5 and SnO on structure, physical and electrical properties of lithium copper fluorophosphate glasses

In the present study, a series of glasses are produced via a melt quenching technique based on the lithium copper fluorophosphate system. The influences of V2O5/P2O5 and SnO/CuO substitutions on the structural, physical, and electrical properties of prepared glasses were examined. FTIR results demonstrated that the rigidity of glass structures was increased by the addition of vanadium oxide instead of Phosphorus pentoxide while it decreased with SnO/ CuO substitutions. The synthesized glasses showed density values in the range of 2.73–3.19 ρ g/cm3 and molar a volume 37.90–38.92 (cc/mol).The AC conductivity and dielectric properties of the prepared glasses were studied in the wide frequency range of 0.1 Hz–5 MHz at room temperature using a high resolution alpha dielectric analyzer. The electric modulus of the investigated samples showed that the trend of its imaginary part (M″) was in tandem with the behavior of AC conductivity. The results of the electrical properties proved that the dielectric parameters are enhanced with V2O5/P2O5 replacement while they doubled four times when CuO was replaced by SnO.

Influence of SrO on structural, optical and electrical properties of LiF-MgO-Bi2O3- SiO2 glasses for energy storage applications

Lithium strontium magnesium bismuth silicate glasses having composition 40SiO2 - 20Bi2O3- 20LiF - (20 - x) MgO–xSrO (x = 0, 5, 10, 15, and 20 mole%) were prepared using melt quenching technique. The prepared samples were characterized using XRD and FTIR techniques. Physical, optical and electrical properties have been investigated in order to understand the mixed modifier effect of MgO and SrO on these glasses. It was found that the addition of strontium at the expense of magnesium increases the density while decreasing the molar volume of the prepared samples. The XRD patterns showed that replacing magnesium with strontium led to enhance the vitreous formation of the prepared samples. Absorbance spectra, energy band-gap and Urbach energy were measured and calculated and the present glass system shows indirectly allowed transitions. Broadband Dielectric Spectroscopy measurements were carried in the frequency range 0.1 Hz to 10 MHz using a high resolution alpha dielectric analyzer in a temperature range from 25 to 200 °C. It was found that the dielectric parameters are enhanced with the increase in MgO content at the expense of SrO and with increasing temperature. The conductivity of the glass shows no dc conductivity behavior except at high temperature and yet it is non-conducting glass. However, the data suggest that the prepared glasses are promising for energy storage glass applications.

Diagnostics of High Water Content Paper-Oil Transformer Insulation Based on the Temperature and Frequency Dependencies of the Loss Tangent

The aim of the work was to prepare and test a paper-oil insulation system according to the recommendations of CIGRE (Conseil International des Grands Réseaux Électriques) with the parameters X = 50% and Y = 30%. Pressboard was moistened to a water content of (5.0 ± 0.2) wt.% The loss tangent was measured using a DIRANA meter (FDS-PDC dielectric response analyzer) in the frequency range 10−4 Hz–5000 Hz for 6 temperatures from 293.15 K to 333.15 K with a step of 8 K. The waveforms simulated by the DIRANA software were fitted to the experimental dependence of the loss tangent. The fitting process was performed using two methods. In the first method, the measuring temperature value as well as X and Y values were entered into the software. The estimated moisture content of the insulation varied from about 1.4 to about 5.2 wt.%. The average value of moisture content was (3.73 ± 1.11) wt.%. In the second method, only the measuring temperature value was entered into the software. This improved the quality of matching. The estimated average moisture content was (5.83 ± 0.25) wt.%. It was found that the dimensions of the oil channel clearly affected the quality of the fitting process. By not taking into consideration real values of oil channel, the quality of the moisture content estimation was significantly improved.

Magnetic susceptibility and frequency dependence ac conductivity of PPY/PANI/V2O5 nanosheets

The conducting copolymer (CCP) Polypyrrole (PPY)/ Polyaniline (PANI) and polycrystalline conducting copolymer nanocomposites (CCPNCs) PPY/PANI/V2O5 were synthesized by in situ chemical oxidative polymerization with nano-particles (NPs) V2O5 using FeCl3 as an oxidant and HCl as dopant by keeping different molar weight percent of V2O5 with pyrrole and aniline. The chemical structures of prepared PPY, PANI, PPY/PANI, V2O5 and CCPNCs are characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) techniques. Scanning electron microscopy (SEM) were used to characterize the surface morphologies of the PPY, PANI, NPs and the CCPNCs shows some nanosheets having thickness about 28 nm. The grains are highly agglomerated and well interconnected with each other. XRD patterns of the CPNCs shows significant effect of change in weight % of additives V2O5 on polycrystalline structure and shows variation in crystallinity. FTIR reveals the broad absorption bands in the range 1100 – 1150 cm−1, which confirms the formation of polymers and absorption bands in the lower frequency regions (750 to 400 cm−1) confirm the existence of MO groups in the hybrids. Magnetic susceptibility increases as increase in magnetic field shows paramagnetic behaviour of CP, CCP and CCPNCs powder at room temperature studied by Gouy’s method. A gradual increment in ac conductivity of CP and CCP were observed with increase in frequency and with increase in temperature, revealing its semi-conducting behaviour. CCPNCs pellets also demonstrated a similar trend with increase in conductivity is the effect of different weight % of additive studied by computer control High Resolution Dielectric Analyser.

Thermal and Dielectric Properties of Cyanate Ester Cured Main Chain Rigid-Rod Epoxy Resin.

Thermal and dielectric properties of rigid-rod bifunctional epoxy resin 4,4-bis(2,3-epoxypropoxy) biphenyl epoxy (BP) and commercial epoxy resin diglycidyl ether of bisphenol A (DGEBA) were studied using differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), dynamic mechanical analyzer (DMA), thermal mechanical analyzer (TMA) and dielectric analyzer (DEA). These two epoxies were cured with cyanate ester hardener 2,2’-bis(4-cyanatophenyl) propane (AroCy B10). The BP/B10 system consisting of a rigid-rod structure exhibited better thermal properties than the DGEBA/B10 system with a flexible structure. Anisotropic BP/B10 (2:1) had the highest 5% weight loss temperature, the highest amount of residue and a smaller thermal expansion coefficient than the commercial DGEBA/B10 system. The BP/B10 system, which cured at the LC phase temperature, had higher Tg than the commercial DGEBA/B10 system, as found from dynamic mechanical analysis. The BP/B10 system also demonstrated better dielectric properties than the commercial DGEBA/B10 system when enough curing agent was provided.

Investigation of structural, dielectric, impedance and magnetic properties of BiFe1-xInxO3 (0.0 ≤ x ≤ 0.6) ceramics

Indium substituted BiFe1-xInxO3 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) ceramics were synthesised via solid reactions method. The samples’ microstructure, dielectric, electrical and magnetic properties were investigated by X-rays diffractions (XRD), scanning electron microscopy (SEM), dielectric analyser, electrometer and vibrating sample magnetometer (VSM). From XRD, pristine BFO sample exhibited single phase rhombohedral crystal structure, space group R3c 161. Introduction of In+3 into BFO matrix promoted the growth of BiInO3 and Bi25FeO40 phases, however, BFO remained the dominant phase up to x = 0.4. Form SEM results, BFO exhibited large homogeneous grain morphology with average grain size 2.04 µm, that get distorted, decreased with introduction of In+3. From magnetic analysis, pure BFO showed antiferromagnetic behaviour while weak ferromagnetic was observed with In3+ substitution. The highest magnetisation 0.04 emu/g and magnetic remanence 6.22 × 10−4 emu/g were recorded for sample x = 0.3. Dielectric measurement showed increasing of dielectric constant εʹr from 26.5 for pure BFO to 372 for sample x = 0.6. The leakage current density was reduced with x from 9.24 × 10−4 A/cm2 for pure BFO to 9.8 × 10−7 for sample x = 0.6. A/cm2. Impedance spectroscopy and dielectric modulus were used to further understand the dielectric behaviour of the samples and the relevant results were analysed and discussed in detail.

Investigation of structural, optical, antibacterial, and dielectric properties of V-doped copper oxide thin films: Comparison with undoped copper oxide thin films

Vanadium doped Copper oxide (CO) thin films were prepared by the sol-gel dip-coating method. The properties of thin films were examined by X-Ray Diffractometer (XRD), UV–Visible-NIR spectrophotometry, and dielectric properties analyzer. The antibacterial and photocatalytic properties were also determined. XRD spectra revealed the dual-phase of copper oxide (cuprite and tenorite) for all percentages of V with no other impurity peak. Tauc's relation is used to probe the optical band gap which is reduced from 1.96 to 1.64 eV with an increase in vanadium doping percentage. The impurity band coalesces with the conduction band of copper oxide to decrease the band gap. Dielectric constant measurements reveal that the Ac conductivity of thin films increases with an increase in V doping percentage.

Dielectric and Thermal Behavior of Polystyrene/Sr2TiMnO6 (STMO) Composites

Materials with high dielectric permittivity are in demand due to their potential applications in microelectronics, capacitors and related fields. Polymer/ceramic composites, due to their improved properties, can be studied to meet this demand. In this work, high permittivity double perovskite Sr2TiMnO6 (STMO) ceramics were synthesized by solid state reaction route and polystyrene (PS) composite thick films (∼200 μm) with up to 50 vol% loading of STMO were prepared by solution casting technique. The composite films were characterized using X-ray diffraction and Fourier transform infra-red spectroscopy for their structural properties. Microstructure of the composites was examined using scanning electron microscopy. Thermal behavior was studied using differential scanning calorimetry and thermo-gravimetric analysis. Dielectric properties, such as permittivity, loss and AC conductivity were measured using a dielectric impedance analyzer. Permittivity and dielectric loss of the base polymer were found to increase with the addition of STMO. Glass transition for composites shifted to higher temperature than that of pure PS. The composites exhibited enhanced thermal stability and these composite films can be explored as dielectric materials for capacitor applications.

Dielectric Spectroscopy of Low Voltage Nuclear Power Cables Under Simultaneous Thermal and Mechanical Stresses

The insulation integrity of power and instrumentation & control cables plays a crucial role in the safe and reliable operation of nuclear power plants. Different stresses affect the insulating materials of these cables, which significantly contribute the structural changes results in the polymeric insulation. Consequently, the polymer material loses its mechanical and electrical properties causing cable insulation degradation. In this work, samples of low voltage nuclear power cable have been studied with accelerated aging tests. Combined simultaneous thermal and mechanical stresses have been applied to all samples under study. While the samples being placed in an air circulating oven at 120 °C temperature, they are coiled on a cylinder with diameter of 15 cm. The dielectric properties, capacitance and dissipation factor were measured by frequency swapping from 100 mHz to 1 kHz using a commercial dielectric response analyzer. Also, the shore D hardness was measured to investigate the changes in the mechanical property of the test specimens. Over the whole frequency range, the capacitance showed a downward trend with aging. In addition, the tanδ increased with aging for frequencies higher 10 Hz. A correlation between tanδ at 100 Hz and the insulation hardness was obtained.

Polymerization of 2-hydroxyethyl methacrylate by hydro/solvothermal technique in presence of nanographene: electrical and thermal degradation characterization

Nanocomposites of poly(2-hydroxyethyl methacrylate) (PHEMA) loaded with 1.7 mass%, 6.5 mass% and 9.0 mass% nanographene were prepared by hydro/solvothermal technique. The main peaks of the nanographene and amorphous polymer structure were revealed by X-ray diffraction (XRD) analysis. Nanocomposites were characterized by SEM, DSC and TGA techniques. The dielectric constant (eʹ), the dielectric loss factor (eʺ), the loss tangent (tanδ) and the conductivity (σac) were measured using a dielectric analyzer in a frequency range from 100 Hz to 2 kHz. Also, current (I)–voltage (V) measurements were carried out. It is well known that nanocomposite formation causes an improvement of many properties for a polymer, providing enhanced properties such as conductivity and thermal stability. This investigation was done to understand whether the presence of nanographene causes changes in the degradation pathway of poly(HEMA) prepared by hydro/solvothermal technique. For this aim, pure poly(HEMA) and nanocomposites were heated from room temperature to 500 °C. The characterization of degradation products for the cold ring fractions (CRFs) and trapped at − 196 °C (in liquid nitrogen) was investigated by means of FT-IR, 1H, 13C-NMR spectroscopic and GC–MS techniques. The FT-IR, NMR and GC–MS data showed that depolymerization corresponding to monomer (2-hydroxyethyl methacrylate) was the most important product trapped at CRF and − 196 °C in the thermal degradation of nanocomposites. As the nanographene loading increased in composite systems, the rate of depolymerization of poly(HEMA) increased compared to pure poly(HEMA). The nanographene particles in the composite systems acted as a mass barrier that retards the escape of the volatile products

Dielectric properties of barium titanium ceramics doped by lanthanum oxide

The method of oxalate co-precipitation assisted with microwave is used for the synthesis of pure barium titanate (BT) particle with a diameter of 30–50 nm by choosing tetrabutyl titanate Ti(OC4H9)4 (98.0%), barium nitrate Ba(NO3)2 (99.5%), oxalate H2C2O4 (99.5% purity) and nitric acid HNO3 (65 ∼ 68%) as starting materials. Lanthanum oxide is doped in barium titanate powders to prepare ceramics by pelleting, forming, dumping, sintering and other steps. The structure and morphology of ceramics are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The dielectric constant and dielectric loss are obtained by dielectric frequency analyzer. The results show that grain size and tetragonality of the barium titanate ceramics doped by lanthanum oxide sintered at 1270 °C for 3 h are found to decrease with the increase of dopants concentration. Dielectric constant increases at first and then decreases as La2O3 concentrations grow, reaching the maximum value when the concentration is 0.3 mol%. The ceramic samples transform from normal ferroelectric to the ferroelectric with diffused phase transition.

Dielectric properties of natural Borneo woods: Keranji, Kayu Malam, and Kumpang

The dielectric behavior and properties of three types of Sarawak woods, under various conditions (untreated, alkaline treated, potassium carbonate treated, and heat treated), were investigated and discussed. The dielectric constant, loss, and dissipation factor tests were conducted via a dielectric impedance analyzer. The results revealed that the dielectric properties decreased in relation to an increase in frequency. With considerations to the treatment method, the highest dielectric constant values for the untreated samples were found in Kumpang wood, the highest dielectric constant values for the heat-treated samples and potassium carbonate treated samples were found in Keranji wood, and the highest dielectric constant values for sodium hydroxide treated samples were found in Kayu Malam wood. Therefore, it was evident that the physical properties, e.g., internal structure, density, moisture, temperature, etc., could affect the dielectric behavior and properties of the wood materials.

Experimental Analysis on Double Layer Kapton Material using Peltier Thermoelectric Device

Kapton is one of the flexible materials used in the development of microwave components for the telecommunications system. The electrical properties of Kapton are dependent on the material's temperature. In this study, this material will be heated, and the electrical properties of dielectric permittivity and loss tangent will be analyzed. This material heating process is done by using Peltier thermoelectric which is installed with Aluminium alloy. The 0 V up to 7 V DC voltage was supplied to the Peltier during the heating process. Then, the electrical properties of Kapton were measured by using a dielectric probe and vector network analyzer (VNA) at frequencies of 1 GHz to 9 GHz. The results obtained show the Kapton temperature was increased from 27 o C to 41 o C. Meanwhile, the dielectric permittivity also varied from 1.72 to 1.64 at the frequency of 5 GHz when 4 V was used. The maximum loss tangent value of 0.5 was observed when the maximum DC voltage of 7 V was applied. The knowledge of this experimental work can be used to design reconfigurable microwave components for smart system applications

Incorporation of graphite into iron decorated polypyrrole for dielectric and EMI shielding applications

Synthesis of polypyrrole (PPy) / graphite (G) composites via chemical oxidation polymerization method is reported. Synthesized composites were studied for its structural, optical and electrical properties. Structural and morphological studies were performed using powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and the effect of graphite on the properties of PPy is elaborated in detail. Further, the electrical measurements were carried using dielectric analyzer. Dielectric behavior of the composites was also compared with the PPy and graphite and confirmed the dependency of graphite on PPy/graphite nanocomposites. The EMI shielding response of PPy/graphite nanocomposites were measured in the microwave frequency range from 12 to 18 GHz (Ku band), of practical relevance. The observed effective electrical and EMI shielding properties highlights the prospects of multifunctional applications of these PPy/graphite nanocomposites.