Three-Dimensional Printing of Acrylonitrile Butadiene Styrene Microreactors for Photocatalytic Applications

Abstract

Miniaturization is a key aspect for many technological applications and the use of microreactors is an excellent solution for the intensification of chemical processes for a variety of applications. However, standard microfabrication requires large facilities and intricate fabrication protocols, and consequently it is not easily available, generally resulting in high production costs. Herein, we present a very cheap, fast and easy microreactor design for photocatalytic applications based on direct fused filament 3D printing as a facilitating and 2 widespread technology. The microreactor consists of three bodies directly printed in ABS (Acrylonitrile Butadiene Styrene): a main body with a serpentine microchannel pattern where the photocatalyst is placed, a top holder with a transparent polymer window, and a base to clamp the parts. Several microreactor units were coated with TiO 2 doped with Cu (2.4 wt.%) nanoparticles synthesized by FSP (Flame Spray Pyrolysis) and tested for the photocatalytic degradation of two water pollutants showing excellent performance. INTRODUCTIONGreen chemistry is a route toward production sustainability, and microreactors are one of the tools available to make it possible, thanks to their enhanced mass and heat transport properties in comparison to conventional reactors. 1-3 A microreactor is a device with interconnected microchannels in which a chemical reaction is carried out. The inner characteristic dimensions are typically below 1 mm. This miniaturization mainly offers high surface-to-volume ratio, controllable interaction between reactants and mass diffusion, lower energy consumption, excellent heat exchange and temperature control, minimization of light loss in photoreactions, better product selectivity, and the opportunity to integrate processes in an automated manner. [4][5][6] These features make microreactors an ideal solution to handle multiple reaction systems, [7][8][9][10] especially in heterogeneous photocatalysis, where a close interaction between the incident light, catalyst and reactants is much needed and hardly achieved in conventional systems. 11,12 Microreactors, like other microfluidic devices, can be manufactured by different techniques such as standard photolithography, soft lithography, micromolding or laser ablation, and a large variety of construction materials are available, such as silicon, glass, polymers, and metals. 13,14 Mainly, polydimethylsiloxane (PDMS) elastomer has been used as construction material due to its outstanding properties of biocompatibility, flexibility, and optical transparency in the UV-Vis

Additive Manufacturing: A Paradigm Shift in Revolutionizing Catalysis with 3D Printed Photocatalysts and Electrocatalysts Toward Environmental Sustainability

“…Revolving around TiO 2 ‐based photocatalyst, microreactor individual parts were printed using FFF, followed by drop‐coating with Cu‐TiO 2 and assembly ( Figure C). [ 228 ] The printed ABS/Cu‐TiO 2 microreactor was able to achieve 95% MB conversion, in comparison to bare TiO 2 at only 80%. In another study, a polydimethylsiloxane‐based (PDMS) transparent silicone microreactor with homogenously distributed Au@POM/TiO 2 coating was fabricated (Figure 11D).…”

“…Reproduced with permission. [ 228 ] Copyright 2020, American Chemical Society. D) 3Dp of ABS decorated with Au@POM.…”

“…C) ABS/TiO 2 microreactor for MB degradation. Reproduced with permission [228]. Copyright 2020, American Chemical Society.…”