Nano-scale surface modification of polymer with carbon particles and microwave

Abstract

The surface morphology of polymers and polymer composites is an important issue for the electrical conductance through electrically conducting composites and adhesively bonded composite structures. Therefore, in this thesis, a surface modification technique for polymers and polymer composites was developed, which could be applied to the various industrial fields such as carbon fiber/epoxy composite bipolar plates and glass fiber/epoxy composite bonding structures. The purposes of surface modification are to generate grooves at the surface for the increase of surface roughness as well as to change the surface components, which improves the electrical conductance or bonding reliability of polymer composites without degradation of polymer or fiber damages of composites. Therefore, an effective surface modification technique is needed for the reliable composite products with high performance. In this thesis, the surface modification technique which could generate nano-scale grooves by thermal decomposition with change of surface components of polymers was developed with microwave heating of carbon particles. In order to generate grooves on the surface of polymer and polymer composite, nano-scale carbon black and CNT (carbon nanotube) mixed with quartz particles were heated by microwave with high rate of temperature increase on the surface of specimens. A high temperature region could be generated around carbon particles, which could induce the generation of grooves by thermal decomposition in few seconds. The heat generation and penetration depth of microwave were investigated to examine the heating phenomenon of carbon mixture. Also, the finite element model for heat transfer was constructed to investigate the generation of grooves at the surface of specimens. The process for the surface modification was designed based on the investigation. In the process, quartz particles were used as spacers between carbon particles to avoid aggregation of carbon particles rathe...