FUNCTIONALLY GRADED EPOXY COMPOSITES USING SILANE COUPLING AGENT FUNCTIONALIZED MULTIWALLED CARBON NANOTUBES

Abstract

Functionally graded multiwalled carbon nanotube (MWCNT) reinforced epoxy matrix composites are fabricated using a centrifugal method. Aggregation of the MWCNTs during the epoxy curing process is prevented using a two-step aminosilane modification. Chemical interaction of the silane with the oxidized nanotube surface is confirmed using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Raman spectroscopy of acid-treated MWCNTs corroborates the formation of surface defects owing to the introduction of carboxyl groups. The mechanical and microwave absorption property gradients of the composites correspond with those produced via silane modification indicating potential application to microwave absorbing materials. The MWCNTs are better dispersed in the epoxy resin after the modification, making it possible for them to become efficiently graded in the epoxy matrix. We therefore show that it is possible to fabricate functionally graded nanofiller-reinforced materials using the centrifugal method by modifying the surface of the nanofiller.