Preparation and electrostrictive properties of polyurethane filled with polypyrrole-carbon black for the energy harvesting application

The polymer composites based on electrostrictive materials with high polarization are attracting scientists because of the prospect of application in energy conversion and electromechanical performance. Polyurethane is one of a good flexible dielectric polymers which is more interesting in electromechanical applications due to its easy fabrication, high dielectric constant, and high electrostrictive coefficient. This work focuses on the dielectric properties and electrostrictive properties of Polyurethane (PU) filled with Polypyrrole-Carbon Black (PPy-CB) various the different concentrations. All polymer composites were prepared by using a film-casting process in solution with DMF solvent. The dielectric properties and conductivity of thin films were investigated by using LCR meter at 1-105 Hz. The results showed that the dielectric constant of composites significantly increases when the concentration of PPy-CB was increased. Moreover, the electrostrictive coefficient of composites also increases when the concentration of PPy-CB was increased. Furthermore, the electrical breakdown stretches were analyzed by using the Weibull model, this result will discuss the relationship when the PPy-CB fillers were used.

Energy conversion of electrostrictive poly(vinylidene fluoride-co-hexafluoropropylene)/Graphene composites

This study investigates energy-conversion properties of the electrostrictive polymer, poly(vinylidene fluoride-co-hexafluoropropylene), P(VDF-HFP), filled with graphene nanosheets (GNPs). The composites (i.e., P(VDF-HFP) and GNPs) were fabricated by using the solution casting method. The dielectric constant of these electrostrictive materials was measured to observe the energy conversion property with different frequencies using an LCR meter. Their mechanical properties were measured using a photonic sensor with varying various input vibrations and electric fields to calculate their electrostrictive coefficients. These characterized results revealed that dielectric constants and electrostrictive coefficients were significantly increased when GNPs fillers were filled higher. For the electrical property, the generating current, which was measured across these polymer films, increased proportionally with respect to the adding GNPs. In this obtained result, the main finding of P(VDF-HFP)/GNPs composites is a promising electrostrictive material for applications of electromechanical energy conversions in many smart-material systems.

Study of Electrical and Thermal Properties of PVA-Nanosilica as A Candidate for Supercapacitor Separators

Separator in the supercapacitor that separates the cathode from the anode has an important role in a supercapacitor circuit. Polyvinyl Alcohol (PVA) is a substitute for polyolefin which is commonly used as a supercapacitor separator and PVA has more environmentally friendly properties. The addition of silica dioxide nanocomposites is useful for adding thermal stability and electrical insulators. The method used to make the separator is quite simple, namely by casting a PVA gel membrane with nanosilica on a glass plate and drying it at low temperature. PVA membrane with nanosilica variations different precursors are from sand by coprecipitation method and from TEOS. The properties of the two samples were characterized by scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), and LCR meter. Nanosilica derived from sand and from TEOS have no much different characteristic.

Kajian Mikrostruktur dan Dielektrik Nanopartikel MnFe2O4 Yang Disintesis Dengan Metode Kopresipitasi

Telah dilakukan penelitian sintesis dan karakterisasi nanopartikel manganese ferrite dengan metode kopresipitasi pada suhu rendah yaitu 900C. Tujuan penelitian ini adalah untuk mengetahui pengaruh suhu rendah terhadap microstruktur dan sifat dielektrik pada nanopartikel MnFe2O4. Sintesis nanopartikel dilakukan dengan metode kopresipitasi, karakterisasi menggunakan XRD dan uji sifat dielektrik menggunakan LCR Meter. Data pengukuran XRD diolah mengggunakan Software Origin 9.0. Ukuran kristalit yang diperoleh adalah 5,79 nm pada suhu 90 °C, 5,65 nm pada suhu 120 °C dan 5,47 nm pada suhu 150 °C dengan parameter kisi rata-rata 9,16 Å. Ukuran kristalit dapat terkontrol menggunakan metode sintesis pada suhu rendahNilai dielektrik tertinggi dihasilkan pada suhu 150 °C yaitu 0,41 x 106 dengan nilai kapasitansi 4,59 x 10-8 F. Peningkatan konstanta dielektrik terjadi karena meningkatnya suhu pemanasan oven sedangkan ukuran kristalit yang dihasilkan lebih kecil.

Plasticizer effect on dielectric properties of poly(methyl methacrylate)/titanium dioxide composites

The effect of plasticizer on dielectric properties of poly(methyl methacrylate) (PMMA)/titanium dioxide (TiO2) composites was investigated. Propylene carbonate (PC) was used as plasticizer in the samples which were prepared with the conventional solvent casting technique. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDX) and Differential scanning calorimetry (DSC) analyses and LCR Meter measurements (performed between 300 K and 400 K), were conducted to examine the properties of the composites. With the addition of plasticizer, the thermal properties have changed and the dielectric constant of the composite has increased significantly. The glass transition temperature of pure PMMA measured 121.7°C and this value did not change significantly with the addition of TiO2, however, 112°C was measured in the sample with the addition 4 ml of PC. While the dielectric constant of pure PMMA was 3.64, the ε′ value increased to 5.66 with the addition of TiO2 and reached 12.6 with the addition of 4 ml PC. These changes have been attributed to increase in amorphous ratio that facilitates polymer dipolar and segmental mobility.

Dielectric spectroscopy and structural characterization of nano-filler-loaded epoxy resin

This work outlines the characterization of epoxy resin [Bisphenol A-(epichlorhydrin): epoxy] and hardener [[Formula: see text](3-dimethylaminopropyl)-1,3-propylenediamine] with various inorganic nano-fillers. Dielectric characterizations of epoxy, hardener, neat epoxy (epoxy + hardener) and nano-epoxy (nano-filler + neat epoxy) composites loaded with 1 wt.% of inorganic nano-fillers (SiO2, Al2O3, TiO2 and ZnO) were carried out using precision LCR meter, over the frequency range of 1 kHz–2 MHz at a constant temperature of 300.15 K. The structural information of nano-fillers, neat epoxy and nano-epoxy composites was understood by Fourier transform infrared spectroscopy and by XRD. Moreover, hardness and shear strength (shear punch) were also determined in order to gain additional information about the mechanical properties of epoxy composite. Influence of inorganic nano-fillers on the dielectric properties, structural chemistry and mechanical properties of neat epoxy composite is discussed thoroughly in this study.

The Effect of Photoconductive Mole Fraction Based on Thin Film BaxSr1-xTiO3 (x = 0.000; 0.125; 0.250; 0.375; 0.500) on Electrical Properties and Diffusivity Coefficient

Barium Strontium Titanate (BaxSr1-xTiO3) thin films have been fabricated for mole fraction (x= 0.000; 0.125; 0.250; 0.375; 0.500) on p-type silicon (100) substrate using Chemical Solution Deposition (CSD) method and spin coating technique. The film annealed at 850 ∘C for 8 hours with an increasing rate of 1.67 ∘C/minute. The BST thin film was characterized using an LCR meter that the film is given a different light intensity (0 lux, 4000 lux, 8000 lux). Data obtained from the LCR meter is conductance, capacitance, and impedance. Different mole fractions on Barium produce different electrical properties that show the value of electric conductivity, dielectric constant, impedance, and diffusion coefficient.