Preparation Of Carbon Nanotubes-graphene Hybrid Nanoparticles And The Performance Investigation Of Silicone Rubber Based Composites

Thermal exfoliation has became a widely used method to produce graphene(GE)due to its advantages of easy operation,low cost and bulk production.However,this method also has obvious defect that often generates multi-layer GE owing to the strongπ-πinteraction between GE sheets,which seriously limits the exertion of its great potentials.In order to solve the above problem,we first mixed graphite oxide dispersion with carboxylated carbon nanotubes(CNTs)and then thermal exfoliation to prevent the re-stacking of GE sheets after thermal exfoliation process with the help of steric hindrance effect of CNTs,which benefits to achieve the homogeneous dispersion of nanofillers in the polymer matrix.We chose two kinds of CNTs with different aspect ratio(AR)to prepare CNTs-GE hybrids by using the above method and then mixed them with SR by solution blending to prepare SR nanocomposites.At last,we investigated the effect of AR of CNTs in the CNTs-GE hybrids on the performance of SR composites.XRD、XPS、Raman、TEM and SEM were applied to investigate and analyze the structure,morphology and dispersion of various nanoparticles,simultaneously the volume resistivity,thermal conductivity,thermal stability and mechanical properties of the SR composites were also studied.The results indicate that the presence of CNTs can effectively impede the stacking of GE sheets.The GE sheets present few-layer even single-layer distribution and the entanglement of CNTs also gets improvement.And the hybrids were dispersed uniformly in the SR matrix.With the addition of CNTs-GE hybrids,the resulted SR composites exhibit greatly improved electrical,thermal and mechanical properties,especially for the composites filled with CNTs-H-GE hybrid.At the hybrids content of 5.0 wt%,the volume resistivity of CNTs-H-GE/SR composites is5.5×10~3Ω·cm,and thermal conductivity is 0.345W/(mK).When the content of CNTs-H-GE hybrid is only 1.0 wt%,the tensile strength of the composites before and after aging is increased to 0.95 MPa and 0.48 MPa,and the initial degradation temperature reaches 419℃,which is obviously better than that of single CNTs or GE filled silicone rubber composites.This research provides a theoretical basis for the efficient utilization of GE or CNTs nanomaterials and realization of multi-function and high-performance of silicone rubber composites.