Developing a Well-Adhered Ni/P Alloy Film on the Surface of Silicone Elastomer for Shielding Electromagnetic Interferences

摘要

Surface metallized silicone elastomer, poly(dimethylsiloxane) (PDMS), using electroless nickel plating (ENP) will find a niche in biomedical applications because it combines the biocompatibility of PDMS with the electromagnetic shielding capability of nickel thin film. However, PDMS is extremely hydrophobic and this makes ENP difficult to be carried out on its surface. In this paper, we report a simple and inexpensive chemical modification method, called the reverse surface roughening approach, which increases the wet-tability of the PDMS surface and thus the adhesion between the metallic deposit and PDMS substrate. In this method, an appropriate amount of surfactant was added into the PDMS matrix to enhance its surface wettability. Furthermore, TiO_2 was attached as an interlayer on the PDMS surface to increase the adhesion between the deposited metallic Ni/P film and the PDMS substrate. On the modified PDMS surface ENP can successfully proceed. Triton X-100 is found to be the most appropriate surfactant as compared to the other surfactants used in terms of its effect on the mechanical properties of PDMS, uniformity of TiO_2 layer and deposition of Ni/P film. The characteristics of the Ni/P deposit, such as structure, morphology, surface resistivity, adhesion and electromagnetic shielding are also investigated to highlight its potential applications in the future.