The electrolytic plating of a metallic nickel on carbon fiber surfaces was carried out to improve mechanical interfacial properties of carbon fiber/epoxy resin composites. The surface characteristics of carbon fibers and the mechanical interfiacial properties of final composites were characterized by X-ray photoelectron spectroscopy(XPS) and interlaminar shear strength(ILSS), respectively. It was found that the electrolytic Ni-plating conditions significantly affected the degree of adhesion at interfaces between carbon fibers and epoxy resin matrix in a composite system. Especially, the increase of O_1s/C_1s ratio, production of NiO groups, and formation of metallic nickel on the nickel-plated carbon fiber surfaces led to an increase of the ILSS of the composites. Also, the ILSS of the composites was greatly correlated with the O_1s/C_1s ratio of the carbon fibers treated in this work.

탄소섬유/에폭시 수지 복합재료의 기계적 계면 결합력을 증가시키기 위해 탄소섬유를 전해니켈도금 표면처리하였다. 탄소섬유의 표면특성과 복합재료의 최종 기계적 물성은 각각 X-ray photoelectron spectroscepy(XPS)와 interlaminar shear strength(ILSS)측정을 통하여 알아보았다. 본 실험결과, 전해 니켈도금은 복합재료의 계면, 즉 강화재인 탄소섬유와 매트릭스간의 계면 결합력에 크게 영향을 미침을 알 수 있었으며, 특히 니켈도금 처리된 탄소섬유 표면에서 O_1s/C_1s 비의 증가와 NiO 그룹 및 금속 니켈의 형성은 기계적 특성인 ILSS증가의 요인으로 작용함을 알 수 있었다. 또한, O_1s/C_1s비는 복합재료의 ILSS와 밀접한 관계가 있음을 고찰하였다.

Keywords: carbon fibers; epoxy resin; electrolytic Ni-plating; XPS; ILSS