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Bisphenol-A resin epoxy resin composites doped with various concentrations of inorganic hybrid nanofillers, TiO2 + ZnO, were thoroughly examined in the research described in this report for their microwave dielectric relaxation spectroscopy. Ultrasonic dispersion techniques were used to disperse the TiO2 + ZnO hybrid nanofiller into the Bisphenol-A resin. X-ray diffraction (XRD) was employed to ascertain the structural characteristics of the TiO2 and ZnO nanoparticles (NPs) and TiO2 + ZnO hybrid NPs doped neat epoxy (epoxy + hardener). A Vector network analyzer was used to measure the dielectric properties of the hybrid NPs doped neat epoxy in the frequency range from 200 MHz to 20 GHz. Our findings offer important new perspectives on the polarization mechanisms and structural properties of these composite materials. The complex relationship between frequency and dielectric characterization led to measurement complexities that often come with extensive time and cost requirements. This paper presents the random forest regression model as an effective method for predicting the frequency-dependent dielectric constants in composite materials. The main objective of this study was to examine the performance metrics, such as the adjusted R-squared score, root mean squared error (RMSE), and mean absolute error (MAE), across various values of the minimum node size parameter (nmin). This study showcases the effectiveness of the RF regression model to accurately and efficiently predict the frequency-dependent dielectric constants in composites. As a result, it eliminates the requirement for laborious and expensive laboratory testing. [ABSTRACT FROM AUTHOR]

The complex relative dielectric function ε∗(f) = ε′ − jε" of aqueous solutions of 1-butyl-3-methylimidazolium chloride [BMiM][Cl] of varying concentrations, has been measured using precision LCR meter in the frequency range 20 Hz to 2 MHz at four different temperatures 293.15, 303.15, 313.15 and 323.15 K. Complex ac conductivity σ* (f) of the liquid samples have been determined from the measured ε* (f). DC conductivity σdc of the samples have also been determined. Values of σdc at different concentrations have been fitted to the empirical Casteel-Amis (CA) equation. The influence of concentration and temperature variation on the complex permittivity and electrical conductivity of the solutions of [BMiM][Cl] in distilled water has been discussed. The molar conductivities and the infinite dilution conductance of these ionic liquids have also been determined. Orientational relaxation behavior of the aqueous solutions of [BMiM][Cl] has also been studied by measuring complex permittivity in the frequency range 1 GHz to 20 GHz using vector network analyzer. Various processes contributed to the electrical/dielectric properties of the solutions of [BMiM][Cl] in distilled water have been explored. [ABSTRACT FROM AUTHOR]

AbstractOur research described in this paper investigated the influence of varying weight percentages of a hybrid nano filler composed of titanium dioxide (TiO2) and silicon dioxide (SiO2) in an epoxy polymer composite. The dielectric properties were analyzed across a broadband frequency range. Additionally, X-ray diffraction (XRD) was employed to examine the structural changes and crystalline phases within the composite materials. The Influence of hybrid inorganic nano-fillers in the epoxy composite on the dielectric properties are discussed thoroughly in this report. To improve material design and prediction modeling, our research utilized machine learning algorithms, such as the XGBoost regressor. The aim was to assess the effectiveness of regression techniques in evaluating the material properties. By employing performance metrics, like R2 score and RMSE, the tests could achieve accuracies ranging from 30% to 60%. Simulation results demonstrated that machine learning-based methods can significantly expedite the forecasting of the dielectric properties, i.e. dielectric constant and dielectric loss at intermediate frequencies, thereby saving both time and energy. [ABSTRACT FROM AUTHOR]