Upcycling aerospace scrap materials into new membranes

A new membrane for separating emulsions is being fabricated using recycled carbon-fiber production scraps from aerospace manufacturing. “We think this is the first membrane of its type to be constructed from recycled carbon fibers,” explains Shuaifei Zhao, senior research fellow in the Institute for Frontier Materials (IFM) at Deakin University (Victoria, Australia; www.deakin.edu.au), where the new membrane was developed. In order to prepare the scrap carbon fibers for use in the membranes, the IFM team applied a specialized recycling process involving pyrolysis, thermal oxidation and ball milling. “Typically, the spent composite was heated in a nitrogen atmosphere at high temperatures to degrade the polymer resin, forming a char on the fibers. Then, the material is heated again in air, which provides an oxidizing atmosphere to completely degrade any residual char and oxidize residual char from the fiber surface,” says Zhao. Once these treatment steps are complete, the reclaimed fibers undergo ball milling and sieving to obtain the desired fiber length. To fabricate the membrane, a dip-coating method was used wherein the substrate membrane was dipped into a dispersion of functionalized carbon fibers in tannic acid (a common…