Influence of polyethylene glycol 6000 and potassium ferrocyanide on electroless copper plating at the nickel-modified surface of para-aramid fibers

Abstract

Influence of polyethylene glycol 6000 (PEG6000) and potassium ferrocyanide (K₄Fe(CN)₆) on electroless copper plating at the nickel-modified surface of para-aramid fibers was investigated in the present work. The surface of para-aramid fibers was roughened using sodium hydride/dimethyl sulfoxide (NaH/DMSO) to guarantee successful electroless plating. Then, electroless copper plating at the nickel-modified surface of para-aramid fibers was adopted because nickel had catalytic activity during the electroless copper-plating process. Meanwhile, PEG6000 can regulate the growth rate of the crystalline grain to produce a morphology-controlled deposit and K₄Fe(CN)₆ is a brightener and leveling agent for deposit during electroless-plating process. Hence, both PEG6000 and K₄Fe(CN)₆ were selected as the additives together. On adding PEG6000 to the plating solution, the copper grains turned fine and sleek. Copper deposits became homogeneous, smooth, and compact, and the appearance of deposits changed from dark-brown to red-brown. On adding K₄Fe(CN)₆ into the plating solution with 4 mg/L PEG6000, the copper deposits became more compact and smoother, and the color of deposits changed from red-brown to bright copper. Correspondingly, the conductivity of deposits increased. In addition, the breaking strength of metal-deposited para-aramid fibers still remained at values up to 45 N.