Abstract
Atomic-level defects dictate the mechanical properties of carbon fibers and strong correlations have been established between the crystallite sizes and mechanical properties. We recently demonstrated similar correlations with hydrogen content, but reliably quantifying the hydrogen content is not possible using only inelastic neutron scattering experiments. Here, we present prompt-gamma activation analysis (PGAA) experiments collected on 20 commercially available carbon fibers to quantify the hydrogen content of carbon fibers and find correlations between fiber modulus and hydrogen content. We then evaluate the role of hydrogen defect type and connect the PGAA results to both newly acquired and recently reported inelastic neutron scattering experiments. We find that intercalated hydrogen defects are preferentially removed at carbonization temperatures required for high-modulus fibers, potentially giving rise to voids within the carbon fibers that undermine their tensile strength.
Original language | English |
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Article number | 093603 |
Journal | Physical Review Materials |
Volume | 7 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2023 |
Funding
This research was funded by the US Department of Energy. A portion of this research used resources at the Spallation Neutron Source, a US Department of Energy Office of Science User Facility operated by Oak Ridge National Laboratory. The authors are grateful to A. E. Shields for assisting with the INS calculations of BPA. This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725.