The overarching goal of this proposal is to establish the feasibility of using an engineered mix of GNPs/CNTs as nanoheaters for rapid and uniform curing of large-scale composite structures OOA with minimal void formation while retaining aerospace/grade properties. This goal will be achieved by: Deposit an engineered mix of GNPs/CNTs nanoheaters on the surface of flat prepregs and dry carbon fabrics using an airbrush to enhance the surface thermal conductivity. Mix CNTs/GNPs with epoxy, apply in between prepregs, and dry carbon fabrics to enhance the volumetric thermal conductivity Monitor and simulate the composite curing thermal profile during Joule heating (as electric current) out of autoclave Examine the microstructure for void formation mechanisms. Microstructural, rheological, mechanical, thermal and electrical characterization of the OOA composites, comparing with baseline products using traditional autoclave curing procedures. Bringing the proposed tasks to fruition will qualify the use of the hybrid CNTs/GNPs nanoheaters for the OOA manufacturing of large-scale composite structures with traditional plate like or tubular composite structures. Two innovative aspects of this proposal are out-of-autoclave (OOA) technologies to eliminate autoclave and usage of more affordable graphene nanoplatelets (GNPs) to partially substitute carbon nanotube (CNT) as nanoheaters. To produce fiber reinforced composites (FRPs) products with high quality with batch repeatability, they are typically processed inside an autoclave, where temperature and pressure are controlled during composite processing. Capital and processing costs using autoclave are extraordinarily high. A large opportunity exists for OOA technologies to reduce the cost and streamline composite manufacturing operations. Most of these techniques still face challenges from several drawbacks such as high porosity due to low level of applied pressure and slow heating rate. Furthermore, most of these techniques are limited to resin systems with low thermal curing temperature; less than 150 °C. Several alternative heating sources were utilized such as infrared and UV radiations and microwave heating. Each of these techniques is limited by energy efficiency, size, and heating depth .
