Structure and thermo-chemical properties of continuous bundles of aligned and stretched electrospun polyacrylonitrile precursor nanofibers collected in a flowing water bath

Effects of chemical composition and post-spinning stretching process on the morphological, structural, and thermo-chemical properties of electrospun polyacrylonitrile copolymer precursor nanofibers

“…However, some macromolecules would possess the conformations that were thermodynamically unstable due to residual stresses, which could further result in stress concentration during the subsequent thermal treatments; as a result, the prepared carbon fibers would possess mechanical defects. The shrinkage in boiling water has been commonly adopted to evaluate the quality of PAN-based precursor fibers [2,10]. …”

“…For example, the T300 carbon fibers with diameters of ~7 µm have the tensile strength of ~3.5 GPa; whereas the T1000 carbon fibers with diameters of ~5 µm have the tensile strength of ~7 GPa [9,10]. In recent years, the technique of electrospinning has been studied extensively as a convenient approach for the preparation of fibers with diameters typically being a few hundred nanometers (commonly known as electrospun nanofibers) [7,11,12].…”

Continuous bundles of aligned electrospun PAN nano-fiber using electrostatic spiral collector and converging coil

“…[27] The tensile strength of nanofiber mats with a concentration of 10 wt% PAN was of 10.89 MPa after heat treatment at 220 °C for 30 minutes. [28] In the near future, we will study the mechanical properties with respect to post-treatment under hot stretching [29,30], stretching in hot water [18,31] and steam.…”

“…[18][19][20][21][22] In particular, a water bath was adopted to collect spun fiber from the surface of the water in electrospinning because the above-mentioned methods to align the fibers [10,11,[14][15][16] cannot possibly produce continuous bundles. However, this may cause cross-contamination in the fiber sample [12], and it also requires higher complexity.…”

A Novel Method for Investigation of Entropic Stress in Prestabilization of PAN‐Based Precursor Fibers

“…Structural imperfections in a precursor, including bulk defects such as cavities, cracks, flaws induced by internal stress as well as voids, entanglements, and disordered structures, reduce strength of resulting carbon fibers. 8 It is clear that high strength PAN precursors are essential to obtain high-performance carbon fibers, because the composition and morphology of the precursors also play a significant role in the carbon fiber production process. [9][10][11] It has been investigated that applying stress along the fiber axis during the prestabilization process is the best method to control entropic relaxation.…”