3D Printing and Chemical Dealloying of a Hierarchically Micro- and Nanoporous Catalyst for Wastewater Purification.

Hierarchically porous-structured materials show tremendous potential for catalytic applications. In this work, a facile method through the combination of three-dimensional (3D) printing and chemical dealloying was employed to synthesize a nanoporous-copper-encapsulating microporous-diamond-cellular-structure (NPC@DCS) catalyst. The developed NPC@DCS catalyst was utilized as a heterogeneous photo-Fenton-like catalyst where its catalytic applications in the remediation of organic wastewater were exemplified. The experimental results demonstrated that the NPC@DCS catalyst possessed a remarkable degradation efficiency in the removal of rhodamine B with a reaction rate of 8.24 × 10-2 min-1 and displayed attractive stability, durability, mineralization capability, and versatility. This work not only manifests the applicability of the proposed NPC@DCS catalyst for wastewater purification in practical applications but also is anticipated to inspire the incorporation of the 3D printing technology and chemical synthesis to design high-performance metal catalysts with tunable hierarchical micro- and nanopores for functional applications.

Mechanical properties and in vitro cytocompatibility of dense and porous Ti-6Al-4V ELI manufactured by selective laser melting technology for biomedical applications.

The Ti-6Al-4V alloy is the most common biomaterial used for bone replacements and reconstructions. Despite its advantages, the Ti-6Al-4V has a high stiffness that can cause stress-shielding. In this work, we demonstrated that the selective laser melting (SLM) technology could be used to fabricate porosity in Ti-6Al-4V extra low interstitial (ELI) to reduce its stiffness while improving cell adhesion and proliferation. With a porosity of 14.04%, the elastic modulus of the porous Ti-6Al-4V ELI was reduced to 80 GPa. The compressive stress and the 3-point-bending flexural tests revealed that the porous Ti-6Al-4V ELI possessed a brittle characteristic. The additional pores within the beams of the lattice structures of porous Ti-6Al-4V ELI increased its surface arithmetic average roughness, Ra = 3.94 µm. The in vitro cytocompatibility test showed that the SLM printing process and the post-processes did not cause any toxicity in the MC3T3-E1 cells. The in vitro cell proliferation test also showed that the porous Ti-6Al-4V ELI increased the proliferation rate of osteogenic induced MC3T3-E1 cells on Day 7. The findings from this study would provide engineers and researchers with both the mechanical information and biological understanding of SLM printed porous Ti-6Al-4V ELI, and SLM printed dense Ti-6Al-4V ELI towards biomedical applications.