Electroless nickel deposition on silicone-rich polyester surfaces

For many applications, the surfaces of the polymeric microstructures must be inert or metallic or chemically tailored. The present work is concerned with the metallization of silicone-rich UV cured polyester. Surface modification of the silicone-rich polyester via argon plasma pretreatment and subsequent UV-induced graft copolymerization with 1-vinylimidazole was carried out to improve the adhesion of electrolessly deposited nickel. The optimum process conditions for argon plasma and UV grafting on the silicone-rich polyester surface were determined. The surface chemistry, energetics, and mechanical roughness of silicone-rich polyester after each step were studied using X-ray photoelectron spectroscopy, contact angle measurements, and atomic force microscopy. The surface-modified silicone-rich polyester was metallized by electroless nickel plating. Scanning electron microscopy results show good Ni/silicone-rich polyester adhesion has been achieved. Based on the conditions optimized in this work, metallized 3D microstructures can be developed. A model study using pure poly (dimethylsiloxane) shows not only the feasibility of electroless nickel plating on pure silicone (and hence the silicone-rich UV curable polyester surface of interest) but also indicates the formation of peroxide or hydroxyl peroxide attached to silicon after argon plasma treatment and aging.