Preparation of Electrospun Porous Alumina Nanofibers for Origami-Inspired Manufacturing

This article presents the fabrication of 3D shapes of alumina nanofibril sheets using origami-inspired manufacturing. The fabrication process includes electrospinning of a composite precursor material for obtaining a nanofibril mat, which is shaped into 3D origami shapes using a sandwich method during a stabilization process. The 3D origami-shaped precursor nanofibril sheet is calcinated at a high temperature to obtain the 3D origami shapes of alumina nanofibers. It is found that the pre-calcination stabilization process plays a major role in determining the morphology of the resulting alumina nanofibers. A hot plate stabilization process leads to the formation of hollow alumina nanofibers during the calcination step, whereas oven stabilization results in a porous morphology of the alumina nanofibers. The oven stabilization is favorable for the origami alumina structures, as it allows uniform stabilization conditions. The alumina nanofibers are majorly mesoporous and feature a surface area ranging from 118 to 505 m2g−1. The compressive modulus of the alumina nanofibers exhibits a dependence on the precursor concentration and calcination temperature. The 3D origami structures of alumina nanofibers exhibit excellent structural stability at high temperatures. The high porosity and high-temperature stability position alumina origami shapes as suitable candidates in many high-temperature applications.