GOALI: Nanomanufacturing of Ultrahigh-Performance Continuous Carbon Nanofibers and Their Assemblies

University Of Nebraska-Lincoln, Lincoln NE

Investigators

Abstract

Continuous carbon nanofibers have advantages over other nanomaterials in terms of cost, ease of handling, processing into useful applications, and possibility of their integration into multi-scale assemblies. However, their mechanical properties need to be substantially improved to improve processability. Due to the small scale of the nanofibers, it is difficult or impossible to use external mechanical constraints during processing that have been successfully utilized in manufacturing conventional larger-scale carbon fibers. Properly constrained nanofibers can match or exceed mechanical properties of conventional fibers; high mechanical performance coupled with low cost processing, small diameter, and ultrahigh surface area will open up broad new areas of nanofiber applications. This Grant Opportunity for Academic Liaison with Industry (GOALI) Program award supports fundamental research to provide needed knowledge for the development of an alternative approach utilizing internal constraints. Unlike the classical external constraint that is only applicable to aligned (one-dimensional) fiber tows, the new process will be applicable to both one-dimensional and two- and three-dimensional nanofiber constructs that can lead to revolutionary affordable high-performance bulk nanostructured carbon products. These multi-scale nanofilamentary structures can be used in a broad range of applications in aerospace, energy, environmental protection, healthcare, biomedical, and automotive industries. Therefore, results from this research will benefit the U.S. economy and society. This research involves several disciplines including manufacturing, electrodynamics process control, and materials science. The multi-disciplinary approach and collaboration with two companies will help broaden participation of underrepresented groups in research and positively impact engineering education. This project's concept of internal constraint during nanomanufacturing of nanofibers can overcome the issues with the classical external mechanical constraint that is instrumental for high mechanical properties of conventional carbon fibers. However, several scientific barriers still need to be resolved to achieve carbon nanofibers? full potential. This research will study the mechanisms of nanofiber structure formation as a result of addition of small quantities of constraining nano-scale inclusions such as carbon nanotubes in all three stages of nanofiber manufacturing, i.e. electrospinning of nanofiber precursors, their oxidative stabilization, and high-temperature carbonization. The research team will perform extensive parametric studies to analyze processing-structure-properties relationships and to select optimal processing parameters for individual nanofibers and their aligned one-dimensional assemblies. Applicability of these parameters to nanomanufacture two- and three- dimensional macroscopic carbon nanofiber constructs in an integrated process will be then explored. The partnership of academic researchers with two companies will help focus this fundamental research on practical issues and will accelerate nanomanufacturing scale-up.