Processing dynamics of carbon nanotube-epoxy nanocomposites during 3D printing

Abstract

Carbon nanotube (CNT)-reinforced polymer nanocomposites are promising candidates for a myriad of applications. Ad hoc CNT-polymer nanocomposite fabrication techniques inherently pose roadblocks to optimized processing, resulting in microstructural defects, i.e., void formation, poor interfacial adhesion, wettability, and agglomeration of CNTs inside the polymer matrix. Here, we show that a 3D printing technique offers improved processing of CNT-polymer nanocomposites. During printing, the shear-induced flow of an engineered nanocomposite ink through the micronozzle is beneficial, as it reduces the number of voids within the epoxy matrix, improves CNT dispersion and adhesion with epoxy, and partially aligns the CNTs. Such microstructural changes result in enhanced mechanical and thermal properties of the nanocomposites compared to their mold-cast counterparts. This work demonstrates the advantages of 3D printing in achieving improved processing dynamics for the fabrication of CNT-polymer nanocomposites with better structural and functional properties.