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Epoxy nanocomposites containing thermally reduced graphene oxides (TRGs) with different oxygen contents were prepared and their mechanical and thermal properties were investigated. It was found that increasing the number of oxygen containing groups on the TRGs resulted in reduced agglomeration of the graphene oxides within the epoxy matrix. Therefore, in samples with a higher oxygen content, a higher interfacial contact area is present between the organic and inorganic phases in the nanocomposite, and so improvements in the storage modulus, break stress, yield stress, thermal decomposition temperature, glass transition temperature, and thermal conductivity were observed.
The effective thermal conductivity and thermal diffusivity was measured for chalcogenide glass samples of the formulation Ge30-xSe70Sbx (x = 10, 15, 20, 25). It was found that both the effective thermal conductivity and thermal diffusivity were independent of temperature up to 160º C. After this point, both properties were found to increase with increasing temperature until they reached a maximum value at a point near the glass transition temperature of the glass. After reaching this maximum, the values were found to decrease. The experimental results were used to develop empirical equations for predicting the effective thermal conductivity and thermal diffusivity. It was found that the equation was in good agreement with the experimental results.
The influence of In content in the Se98-xAg2Inx (x = 0, 2, 4, 6) system of chalcogenide glasses on the physical properties of the glasses were investigated by the authors. The maximum thermal conductivity and thermal diffusivity value was observed for the sample containing 2 at. % In. The microhardness was found to initially decrease upon doping of In for Se; however, it began to slowly increase after a certain In content had been attained. It was concluded that the doping of In into the system resulted in an improvement in the thermomechanical properties of the chalcogenide glasses.
The thermal conductivities of refractory materials often used in the glass production industry were evaluated experimentally. The transient plane source technique was used for the thermal conductivity testing. Specifically, the single-sided method was used to avoid destroying the refractory materials. The thermal conductivity was measured at various locations and it was discovered that there was a variation in thermal conductivity between the hot and cold faces of the brick.
Zinc sulfide nanoparticles were embedded in a poly(methyl methacrylate) matrix to prepare a nanocomposite polymer with a higher thermal conductivity than the pure polymer. It was determined by TEM that at a low concentration of filler particles, the particles are uniformly dispersed throughout the matrix; however, at higher concentrations, agglomeration of the filler particles occurs. The effective thermal conductivity for all samples was found to increase with increasing temperature until the glass transition temperature was attained. After this point, the thermal conductivity became constant as temperature increased. The thermal conductivity was also found to increase with increasing filler content, up to 6 wt. %. The thermal conductivity of the sample containing 8 wt. % ZnS was found to be lower than that containing 6 wt. % ZnS. The authors suggest that this decrease is due to increased particle agglomeration in the 8 wt. % sample.
