Influence of PEG molecular weight on morphology, structure and wettability of electroless deposited Cu–Ni–P films

Cu–Ni–P films with different morphologies were fabricated via electroless deposition route, due to the crystalline modification of polyethylene glycol (PEG). Effect of PEG molecular weight on morphology and structure of Cu–Ni–P films were investigated by field emission scanning electron microscopy and X-ray diffractometer. SEM observation reveals that electrolytes containing PEG 2000, 10000 and 20000, respectively can result in the formation of three kinds of unique architectures: pyramid with star-shaped cross section, cone and column. As PEG molecular weight increases, volume of the as-prepared microstructures increases but density decreases. The XRD pattern indicates the Cu–Ni–P coating is well-crystallized and preferred orientation formed in electrolyte without PEG, with PEG 2000, PEG 10000 and PEG 20000 are (1 1 1), (2 2 0), (1 1 1) and (1 1 1), respectively. Based on the proposition that properties of materials were affected by their size and morphology, wettability of the as-prepared Cu–Ni–P films were investigated. The hydrophobicity of coating deposited with PEG 2000 reached a climax exhibiting a contact angle of 123.8°.