ao9b00278_si_001.pdf (563.88 kB)
Impact of Thermal Oxidative Stabilization on the Performance of Lignin-Based Carbon Nanofiber Mats
journal contribution
posted on 2019-03-15, 08:13 authored by Mijung Cho, Frank K. Ko, Scott RenneckarLignin is a renewable biopolymer
considered as a potential precursor
for low-cost carbon materials. Thermal oxidative stabilization (TOS)
is an important processing step to maintain fiber geometry during
carbonization, yet the impact of TOS on the properties of lignin-based
carbon materials has not been clearly identified in the literature.
Yield, change in fiber diameter/distribution, elemental composition,
and mechanical properties were explored for both stabilized and carbonized
lignin fibers. Vibrational spectroscopy and solid-state 13C nuclear magnetic resonance spectroscopy were used to analyze the
changes in lignin molecular structure after exposure to various heating
conditions during the TOS steps. Further, studies were focused on
the effects of TOS conditions on the resulting carbon structure of
fiber mats through Raman spectroscopy measurements and electrical
conductivity analysis. Although TOS conditions influenced the properties
of the oxidized lignin fiber mats, properties of the carbonized
samples were invariant to the TOS procedures used in this study over
most of the conditions. As a result, there was flexibility for the
parameters (time and temperature) in the TOS process when conditioning
softwood lignin materials for carbon fibers.