Synergetic Effects of Graphene and Nonfunctionalized Carbon Nanotubes Hybrid Reinforced Epoxy Matrix on Mechanical, Thermal and Wettability Properties of Nanocomposites

摘要

In this study we focused on the effect of Graphene Nanoplates (GNPs) and Nonfunctionalized Multi Wall Carbon Nanotubes (MWCNTs) hybrid nanofiller and its dispersion on mechanical, wettability, and thermal stability properties of epoxy nanocomposites. The epoxy resin was mixed with 0.5wt. % (GNPs-MWNTs) by direct mixing method using different (GNPs:MWNTs) ratio as (0:10, 1:9, 2.5:7.5, 5:5, 7.5:2.5, 9:1 and 10:0). The dispersionability of carbon nanofiller in epoxy nanocomposite samples was examined by FESEM. The results indicate that epoxy /GNPs significantly out-perform MWNTs additives. The superiority of GNPs in terms of mechanical properties improvement over MWNTs may be due to their high aspect ratio, improved nanofiller matrix adhesion/interlocking arising from their wrinkled surface, and their geometry (2D structure). The best improvements in mechanical properties was found at two mixing ratios of GNPs: MWNTs (5:5) and (9:1). The improved mechanical properties of epoxy/GNPs- MWNTs hybrid nanocomposite is related to the formation of 3-D hybrid architectures structure in epoxy matrix as confirmed by FESEM observations. The hydrophobicity of Epoxy/0.5 wt. % MWNTs is higher than that of epoxy/0.5wt.% GNPs, where contact angle of Epoxy/MWNTs is larger than that of epoxy/ 0.5wt. % GNPs and water absorption of Epoxy/ 0.5wt. % MWNTs is less than that for epoxy/ 0.5wt. % GNPs. Hydrophilicity of neat epoxy decreases by adding 0.5 wt.% GNPs-MWNTs with mixing ratio 2.5:7.5 where contact angles are changed from 43.5° to 79.5°. Thermogravimetric analysis results for neat epoxy, Epoxy/MWNTs, Epoxy/GNPs, and Epoxy/GNPs-MWNTs do not show any major influence on thermal stability of epoxy.