Transparent, lightweight aluminum-polymer composites for increased-value sample-return missions

This SBIR Phase I project will develop lightweight, high-strength aluminum-based structural components derived from a facile manufacturing process. In previous work, large volumetric fractions of Au, Ag, and Cu nanoparticles (NPs) were incorporated into a porous aramid nanofiber (ANF) matrix to realize films that have high electrical conductivity, yet maintain superior mechanical strength, properties that are usually hard to achieve simultaneously. Furthermore, the composite films demonstrate excellent flexibility, which is superior to other related classes of reported flexible conductors including carbon based nanomaterials (CNTs and graphene) and other metallic materials. The unique network structure enables high electrical conductivity and robust mechanical behavior of the metal-ANF films. Most pertinently for mass-restrictive applications, we previously demonstrated that copper-ANF composites had ~90 % less mass density than solid copper, but with electrical properties (conductivity, ampacity) that were at least 33 % of the bulk value. During Phase I, we will extend the material system to aluminum structural components that are relevant to sample-return missions that require mass-efficient materials. We will first find the lower limits of achievable mass that still provides acceptable conductivity, ampacity, and strength in both cylindrical and polygonal cross-sectional solids. We will then characterize the conductive and insulating properties of self-insulated solids, in which the ANF can be functionalized with various levels of conductivity. We can control the optical properties of the Al-ANF composite by modifying the surface plasmon resonance of the aluminum NPs, knowledge that will be used to make solids of various optical properties. Finally, we will design manufacturing tools to scale-up the production of the solids.nbsp;