Electroless nickel plating on APTHS modified wood veneer for EMI shielding

A new activation process was developed for electroless plating to prepare wood-based EMI shielding material. Pd(II) was adsorbed on a wood surface modified with γ-aminopropyltrihydroxysilane (APTHS) formed by the hydrolysis of γ-aminopropyltriethoxysilane (APTES). After reduction of Pd(II), electroless plating was successfully initiated and an Ni-P coating was deposited on the wood veneer. The activation process and resulting coating were characterized by XPS, SEM-EDS and XRD. The metal deposition, surface resistivity and electromagnetic shielding effectiveness were measured. XPS analysis proved that Pd(II) was bonded to the amino group of APTHS and was reduced to Pd(0). The Ni-P coating was uniform, compact and continuous, and consisted of 3.39 wt.% phosphorus and 96.61 wt.% nickel. XRD analysis indicated that the coating was crystalline, which is thought to be related to the low phosphorus content. The plated birch veneers exhibited electromagnetic shielding effectiveness greater than 60 dB in the frequency range 10 MHz-1.5 GHz.