Fabrication and characterization of hybrid carbon nanotubes / silicafilled epoxy nanocomposites

Carbon nanotube (CNT) was used as reinforcement to improve mechanical and thermal conductivity properties of epoxy. However, agglomeration and homogenous dispersion of CNT in the epoxy matrix remains challenge. Growth of CNT on the surface of silica gels (hybrid CNT) can reduce the agglomeration of CNT in the epoxy. Hybrid CNT was synthesized via floating and non-floating catalyst chemical vapour deposition method (CVD). Regardless reaction time and
reaction temperature, growth of hybrid CNT by floating CVD method was unsuccessful. Considering the result observed from FESEM, HRTEM, TGA and Raman spectroscopy, hybrid CNT that produced from 50 ml/min hydrogen flow rates was selected to prepare the nanocomposite. Result of hybrid CNT epoxy nanocompsoite was compared with silica epoxy composite and CNT epoxy nanocomposite. Inclusion of hybrid CNT at different weight loading (0.1 wt. %, 0.5 wt. %, 1 wt. %, 1.5 wt. %, 3 wt. % and 5 wt. %) was expected to increase glass
transition temperature (Tg) and thermal conductivity properties of epoxy. However, Tg values for all type of nanocomposite (hybrid CNT, CNT and silica) was lower
than neat epoxy except for 1.5 wt. % silica. It also was observed that at all weight loading, silica epoxy composite has higher Tg value compared to CNT and hybrid CNT epoxy nanocomposite. Finally, addition of hybrid CNT into the epoxy also decreases the thermal conductivity value. Lowest thermal conductivity value for hybrid CNT recorded at 5 wt. % with 0.155 W/mK compared to neat epoxy (0.177W/mK).