Disclination Structures in Carbon and Graphite.

Abstract

Carbon materials are structurally unique, owing to their relationship to liquid crystals. Pyrolysis of precursors that pass through a liquid crystalline (mesophase) state is the process by which most carbons form. The lamelliform morphologies that are locked in as the carbonaceous mesophase hardens lack grain boundaries but possess disclinations as their most prominent structural feature. Practical materials, ranging in value from petroleum coke to mesophase carbon fiber, form while the mesophase undergoes deformation, and the disclinations can react extensively before they are entrapped by hardening. Thus, most carbons and graphites may be regarded as mesophase fossils with disclination-dominated microstructures that vary with the nature and extent of deformation and with the time allowed for the disclinations to react and relax before hardening. Keywords: Mesophase, Disclination, Liquid crystal, Coke, Graphite, Pitch, Carbon fiber, Carbonization, Pyrolysis, Oxidation, Stabilization.

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Document Details

Document Type
Technical Report
Publication Date
Dec 31, 1987
Accession Number
ADA191056

Entities

People

  • Jack L. White

Organizations

  • The Aerospace Corporation

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Acrylonitrile Polymers
  • Air Force
  • Carbon Fibers
  • Classification
  • Composite Materials
  • Crystals
  • Fibers
  • Filaments
  • Films
  • Graphitic Materials
  • Liquid Crystals
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Microstructure
  • Security

Readers

  • Combustion science or combustion engineering.
  • Materials Science and Engineering.
  • Polymer Science and Technology