Fabrication and evaluation of structural, thermal, mechanical and optical behavior of epoxy-TEOS/MWCNTs composites for solar cell covering

In the present study, hybrid organic-inorganic composites were fabricated from epoxy-TEOS (tetraethyl orthosilicate, Si(OC2H5)(4)) with various ratios (0-10 wt%) of multiwall carbon nanotubes (MWCNTs) as reinforcing nanofillers by the sol-gel method. The effect of the MWCNTs ratios on the structural, optical and mechanical characteristics and the thermal conductivity of the epoxy-TEOS/MWCNTs composites is investigated. The X-ray diffraction (XRD) analysis reveals that the pure epoxy-TEOS is amorphous, while epoxy-TEOS/MWCNTs composites are crystalline with an orthorhombic crystal structure that has an average crystallite size of 3.9 +/- 0.15 nm. In addition, thermal stability and thermal conductivity were improved by adding TEOS and MWCNTs, whereas the exothermic peak temperature decreases compared with pure epoxy-TEOS. Similarly, the hardness Shore-D and tensile strength reach the optimum value at 4 wt% MWCNTs content. The significant improvement in the mechanical and thermal properties of the prepared composites could be attributed to the synergistic effect of MWCNTs and epoxy-TEOS which was emphasized by Fourier transform infrared (FTIR) spectroscopy. Moreover, epoxy-TEOS sample has high optical transmittance (T) within the visible region, but the composites samples are transparent at lambda < 800 nm and have a lower value ofT. The indirect optical band gap decreases from 3.59 to 2.91 eV with an increase in MWCNTs fractions from 0 to 10 wt%, respectively. However, the glass transition reflects the onset of decomposition temperatures was also considerably increased. The acquired outcomes such as a large increase in thermal conductivity and tensile stress coupled with reducedTmake the composites readily applicable for a variety of applications. [GRAPHICS] .

Automated summary

The addition of MWCNTs into epoxy-TEOS significantly improves the mechanical and thermal properties of the prepared composites, with the best performance achieved at a 4 wt% MWCNTs content.