(255a) Microfluidic Synthesis of Titania Microparticles with Tunable Morphologies | AIChE

(255a) Microfluidic Synthesis of Titania Microparticles with Tunable Morphologies


Campbell, Z. S. - Presenter, North Carolina State University
Jackson, D., North Carolina State University
Lustik, J., North Carolina State University
Al-Rashdi, A. K., North Carolina State University
Bennett, J., North Carolina State University
Li, F., North Carolina State University
Abolhasani, M., NC State University
Metal oxide microparticles, particularly titania (TiO2), have attracted substantial attention for widespread utilization in a variety of applications ranging from photocatalysis to electrochemistry1 due to unique intrinsic physicochemical and optoelectronic properties, including a moderate band gap and good charge transfer characteristics. Over the last three decades, various synthetic methods have been employed in titania synthesis, including solvothermal, sol-gel, emulsion, templating, and microfluidics.2 However, the above methods each present different challenges for synthesizing high-quality monodisperse titania microspheres, including size limitations (≤3 μm), polydispersity, or complicated/labor-intensive synthetic methods.

In this work, we present a microfluidic strategy for facile, controlled synthesis of highly monodisperse titania microparticles with tunable morphology and phase composition, while achieving record-breaking surface areas for micron-sized particles.2,3 The flow reactor is comprised of readily available off-the-shelf components and features a flow-focusing configuration. The developed microfluidic reactor enables continuous microparticle formation with excellent control over microparticle size, surface area, morphology, and crystallinity through the implementation of in-line photo crosslinking of a sacrificial polymeric scaffold. The combination of in-line photocuring and utilization of a polar aprotic solvent as the continuous phase in the microfluidic reactor enables excellent control over process-structure-properties of in flow-synthesized titania microparticles which were previously inaccessible due to the presence of water- and air-sensitive precursors. The available range of precursor compositions in the developed microfluidic synthesis strategy enables on-demand manufacturing of a wide variety of microparticle morphologies, including hollow shell, yolk-shell, macroporous, and dense microspheres, as well as surface areas as high as 360 m2g-1 with diameters ranging from 5 to 250 μm.

1 T. Zhao et al. Nano Energy, 2016, 26, 16–25.

2 Z. S. Campbell et al. Chem. Mater., 2018, 30, 8948–8958.

3 Z. S. Campbell et al. RSC Adv., 2020, 10, 8340–8347.