Fabrication of ultrafine hollow Ni and Ni/Fe fibers and their dispersion characteristics in the epoxy matrix

In order to develop a material with light weight and homogeneous characteristics for the electromagnetic wave absorbing, hollow Ni and Fe metallic micro fibers were fabricated by electroless plating and heat treatment method. It is expected that hollow and fibrous structure of fibers can reduce the weight and increase the efficiency of electromagnetic properties. As a substrate for electroless metal plating, commercial polyester micro fibers were used. The surface of micro fibers was coated with Ni and Ni/Fe metal layers and then heat-treated under the argon atmosphere to make the fiber a hollow structure. The surface morphology and composition were verified by SEM and EDS analyses. Hollow structures of the fibers were observed and the optimal thickness of Ni and Fe layers were about 200–300 and 500–700 nm, respectively. Polymeric composites containing 10, 20 and 30 wt.% of hollow Ni/Fe micro fibers were fabricated by mechanical mixing method. SEM images demonstrated the uniform distribution of hollow metallic micro fibers in the epoxy matrix.