Metallization of 3D-Printed UV Photopolymer Structures by the Incorporation of Pd-Decorated Carbon Nanotubes

Abstract

Pd-decorated carbon nanotube (CNT) nanocomposites were added to a UV photopolymer resin to be used as the ink in the printing of three-dimensional (3D) structures. The nanocomposites were prepared with a UV-induced reduction method, in which Pd nanoparticles with a size ranging from 10 to 150 nm were produced and decorated on CNTs. The printed 3D structures from the resin containing 1.0 wt % Pd-decorated CNTs exhibited much improved mechanical properties, achieving a 40% enhancement in fracture strength and a 40% increase in microhardness over the 3D structures printed from the bare resin. In the presence of Pd-decorated CNTs as catalyst seeds, further deposition of defect-free, nearly conformal Ni–P layer on the 3D-printed structures at a high deposition rate can be realized. The cross-cut adhesion testing revealed a significantly enhanced adhesion between the deposited Ni–P layer and the 3D-printed structures. The metallized 3D-printed structures displayed superior electrical conductivity, showing an electrical resistance down to 0.11 Ω as 1.0 wt % Pd-decorated CNTs were incorporated. The findings from this work highlight the merits of employing Pd-decorated CNTs as both mechanical property enhancer and catalyst seeds in the advanced manufacturing of 3D-printed structures.