High-throughput microstructure and composition characterisation of microplatelet reinforced composites using directional reflectance microscopy

Reinforced composites with controlled microstructure can achieve exceptional mechanical and functional properties. In recent years, scientists have placed in substantial efforts to fabricate reinforced compos-ites with astounding properties through the design of these microstructures. To better understand the structure-property relationships of these materials, it is essential to characterise their microstructural features. However, standard characterisation techniques such as electron-based imaging are costly, time-consuming, and restricted to small-scale samples. In this work, we present a simple, inexpensive, and high-throughput alternative method to assess the surface microstructure of microplatelet reinforced com-posites. The method relies on directional reflectance microscopy (DRM), an optical technique that enables mapping of the filler orientation and weight fraction in these composites using surface reflectance data. We demonstrate the effective use of DRM on reflective microplatelet-reinforced polymeric composites that we prepared using 3D printing and mould casting techniques. Our experimental results showcase the potential of DRM as a high-throughput method to assess microstructural information in reinforced composites. This information could be used to understand how the microplatelets' alignments influence the materials' properties for devising new composite designs.(c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.