Study on the Thermal and Dielectric Properties of SrTiO3/Epoxy Nanocomposites

Abstract

SrTiO 3 /epoxy nanocomposites are prepared using the facile solution-processing technique by incorporating SrTiO 3 nanoparticles with different weight fractions into the epoxy resin host. The morphology of the nanoparticles and composites, as well as the thermal conduction characteristics and electrical properties of the composites were investigated via conventional testing methods. The thermal conductivity increased along with the SrTiO 3 weight fractions, and the thermal conductivity of the SrTiO 3 /epoxy composite with 40 wt % weight fraction increased to 0.52 W/mK. The dielectric constant increased along with the weight fractions and decreased along with frequency, thereby suggesting that the interfacial and dipole polarization do not follow the changes in the electrical field direction at high frequency. The dielectric constants at 1 kHz frequency increased along with temperature. Surface breakdown tests illustrated further improvements in the thermal and electrical properties of the composites. In the same time span of 40 s, the 40 wt % nanocomposite demonstrated a rapid temperature decline rate of 6.77 • C/s, which was 47% faster than that of the pure epoxy sample. The surface breakdown voltage also increased along with the weight fractions. The functional composites can solve the key problem in the intelligentization, miniaturization, and high-efficiency of the gas-insulated switchgear, which warrants further research.

Computational Thermomechanical Properties of Silica–Epoxy Nanocomposites by Molecular Dynamic Simulation

“…In Equation (9), q˙exp and q˙sim are the experimental and simulation cooling rates, respectively, and C1 and C2 are the WLF equation parameters. Using the conventional value for WLF parameters (C1=17.44 and C2=51.6 normalK), the predicted shift in the T g between experimental measurements (a range of q˙exp = 4.88–6.77 K/s [43]) and our simulation (q˙sim=100×109 normalK/normals) is 72.17–74.63 K, a reasonable agreement between the shifted T g from simulation value range of (410–460 K) and experimental value range of (363–420 K) [43].…”

Heat Transfer at the Interface of Graphene Nanoribbons with Different Relative Orientations and Gaps

“…Similarly to the typical empirical expressions adopted for heat transfer, only basic formula building-blocks (i.e., constant, multiplication, division, power) have been considered for the Eureqa fitting. As a result, the simulation results in Table A1 (configurations N. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] have been found to be best fitted (R 2 = 0.99, see Figure 4b) by the following expression:…”

“…Carbon fillers such as carbon nanotubes and graphene nanoribbons are often suggested as possible additives in composite materials. In fact, these materials show a remarkable combination of superior thermal [1][2][3][4], electrical [5][6][7], lubrication [8,9] and mechanical [10][11][12] properties, which have the potential to significantly enhance the performance of base materials. In particular, Polymer Nanocomposites (PNCs) with carbon nanofillers are currently employed in a broad variety of industries, such as the energy [13], aerospace [14], biomedical [15], electronics [16,17] and automotive ones [18,19].…”

Improvement of Heating Uniformity by Limiting the Absorption of Hot Areas in Microwave Processing of CFRP Composites

“…Thus, cold ones can catch up with them in an easier way, thereby improving the temperature uniformity of the laminate (see Figure 2). From the literature survey, we found that strontium titanate (STO) has temperaturedependent dielectric properties, but its dielectric constant is too high (>150 at 2.45 GHz between 25 °C and 200 °C [22,23]). As a result, STO particles were added into a low dielectric epoxy resin matrix to fabricate our dielectric-variable spacer.…”