Controlling the microstructure of metal and polymer foams via microfluidic approaches Thomas Moore 1 , Jamie Mannering 1 , Samantha O’Connell 2 , Naomi Stubbs 2 , Robert Menzel 1 1 University of Leeds, UK, 2 AWE plc., Aldermaston, UK Low density, macroporous metallic and polymeric foams are used as target components for high energy density laser physics experiments. Accordingly, these materials have stringent requirements, which necessitate versatile fabrication methods able to synthesise metal and polymer foams with highly tuneable, bespoke material properties, whilst providing reproducible control of density, uniformity, and void sizes. Current synthesis strategies employ high internal phase emulsions (HIPEs) or solid, colloidal suspensions as templates, 1, 2 however, microfluidics may offer an attractive alternative for the synthesis of monodisperse template materials with greater flexibility. With this in mind, the primary aim of this work is the development of novel fabrication methods for polystyrene and metallic copper foams which employ liquid droplets, generated using droplet microfluidics, as templates that are explicitly designed to influence the properties of the final material. Microfluidic platforms capable of generating droplets with uniform size distributions over 15-400 µm have been investigated, utilising capillary- and glass chip- based microfluidic devices, with size control of microbeads demonstrated by variation of microfluidic flow parameters. Following this, reverse-phase, water-in-oil emulsions generated using microfluidics were explored as templates for macroporous polystyrene foams, to demonstrate control of pore sizes via modulation of microfluidic parameters. This work has shown that open cell polyHIPE-like foams with uniform pores can be templated using microfluidic droplets, but more work is required to translate this into synthesis of materials with relevant properties. References 1. K. Nagai, C. S. A. Musgrave and W. Nazarov, Physics of Plasmas , 2018, 25 , 030501. 2. S. H. Kim, N. Bazin, J. I. Shaw, J.-H. Yoo, M. A. Worsley, J. H. Satcher, J. D. Sain, J. D. Kuntz, S. O. Kucheyev, T. F. Baumann and A. V. Hamza, ACS Applied Materials & Interfaces , 2016, 8 , 34706-34714.
P38
© The Author(s), 2022
Made with FlippingBook Learn more on our blog