Abstract
The production of high-strength carbon fibers is an energy-intensive process, where a significant cost involves the wet or dry-spinning of polyacrylonitrile (PAN) fiber precursors. Melt-spinning PAN fibers would allow for significant reduction in the production cost and production hazards. Ionic liquids (ILs) are an attractive fiber-processing medium because of their negligible vapor pressure and low toxicity. In addition, they are carbon-forming precursors; upon carbonization, residual ILs can enhance the carbon yield, although primarily useful for plasticized melt-spinning of PAN precursor fibers. In this research, we investigated the influence of the molecular structure of ILs and the control of plasticizing interactions with PAN during melt-spinning. The structural, thermal, and mechanical properties of the melt-spun PAN fibers were obtained by a combination of various characterization methods, such as differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and mechanical testing. These results demonstrated that the IL structure and counteranions influence the PAN fiber formation. More specifically, ILs containing bromide counteranions produced PAN precursor fibers with increased mechanical properties compared to ILs containing chloride anions. Our research can provide a foundation to understand the influence of ILs on melt-spinning of PAN fibers and provides us the guidelines for a higher cost-/energy-efficient production of PAN-based carbon fibers.
| Original language | English |
|---|---|
| Pages (from-to) | 8663-8673 |
| Number of pages | 11 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 12 |
| Issue number | 7 |
| DOIs | |
| State | Published - Feb 19 2020 |
Funding
The authors thank Professor David Harper from the Center for Renewable Carbon at the University of Tennessee, Institute of Agriculture, for providing training on the Instron 5943 universal testing machine. Research was sponsored by the Fuel Cell Technologies Office, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy (DOE). Electron microscopy characterization was in part performed at ORNL’s Center for Nanophase Materials Sciences, which is the DOE Office of Science User Facility. This manuscript has been authored by UT-Battelle, LLC under contract no. DEAC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research by the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
Keywords
- PAN fibers
- carbon materials
- ionic liquids
- melt-spinning
- structure effect