Structural characterisation of a high-modulus carbon fibre by high-resolution electron microscopy and electron diffraction

Tensile and interfacial properties of polyacrylonitrile-based carbon fiber after different cryogenic treated condition

“…This may be attributed to the hoop stress in the fiber radial direction induced by shrinkage of the fiber and strengthening of bonding forces between molecules when the temperature decreased from RT to 77 K. Moreover, the reduction of micro-and nano-sized pores in the fiber may affect the changes of interlayer spacing [28,29] because the compression stress may force anisotropic expanding and merging of tiny pores leading to looser molecular packing along the fiber axial direction and tighter molecular arrangement in fiber radial direction when the fibers undertake TPCM process.…”

Pitch-Based Carbon Fibre-Reinforced PEEK Composites: Optimization of Interphase Properties by Water-Based Treatments and Self-Assembly

“…Indeed, we assume that the presence of the polyelectrolyte complex-based film forces the PEEK to get very close to the carbon fibre surface owing to electrostatic interactions and hydrogen bonding. During the cooling phase, the PEEK macromolecules (containing aromatic rings) close to the fibre surface (also made of aromatic rings due to the high density graphitic sheet-like microstructure of the fibre and high preferred orientation in terms of crystallite size [42,43] create ∏-∏ stacking and electrostatic interactions making the fibre surface an effective nucleating site and a large number of nuclei can be induced directly onto the surface. The crystal structure similarity, the high thermal conductivity of the fibre increasing the nucleation, and the high degree of molecular orientation inducing by the polyelectrolyte complexbased coating, allowed a nucleation growth at the interphase, which is thus referred to as transcrystallinity.…”

Recent advances in studies of carbon fibre structure

“…In terms of crystallite thickness there is clearly a size distribution of which L c repre sents an average value. A detailed description of crystallite-size distributions and their measure ment from various lattice-fringe images, and from X-ray and electron diffraction, has been reported by Bennett et al (1976). In terms of layer-plane length, we can see that the actual length as observed in the lattice-fringe image is considerably greater than the X-ray diffraction value Tan, which represents a coherence length related to the straight length of the layer planes.…”

“…These misoriented crystallites could well be the intrinsic flaws suggested by Reynolds & Sharp (1974) as strength limiting features in regions where gross flaws are absent. The distribution of misoriented crystallites in the core region has been described by Bennett al. (1976).…”

“…Further parameters are given in table 3. A full characterization o the core structure, including the distribution of crystallite size with azimuthal angle is given in the paper by Bennett et al (1976).…”