Microstructure and Thermal Expansion Properties of Ostrich Eggshell

Abstract

Textures of calcite crystals from ostrich (Struthio camelus) eggshells were examined with X ray diffractometry (XRD), transmission and scanning electron microscopy (TEM, SEM), and the thermal stability by thermal expansion analysis (TEA). Results showed that textures vary through the thickness of the eggshell and that expansion properties and thermal behaviour are unusual. Crystals from ostrich eggshell are arranged in two main configurations or layers; the outer layer with the c-axis of crystals oriented perpendicular to the eggshell surface and the inner layer with the c-axes of the crystals arranged almost parallel to eggshell surface; thermal expansion analysis show high stability through a wide range of temperatures until a steep growth near 450-460 degrees C. These results show that the manipulation of crystal texture and properties is under biological control and a better understanding of this biological phenomenon will provide more and better data for improving new synthetic composite materials.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2002
Accession Number
ADP014407

Entities

People

  • A. Heredia
  • A. Rodriguez-hernandez
  • C. A. Martinez-matias
  • L. Lozano
  • M. A. Pena-rico

Organizations

  • Yokohama National University

Tags

Communities of Interest

  • Autonomy

DTIC Thesaurus Topics

  • Biopolymers
  • Chemical Reactions
  • Crystal Growth
  • Crystallites
  • Crystals
  • Diffraction
  • Electron Beams
  • Electron Microscopy
  • High Temperature
  • Materials
  • Mechanical Properties
  • Orientation (Direction)
  • Physical Properties
  • Thermal Expansion
  • Thickness
  • Transmission Electron Microscopy
  • X Rays

Readers

  • Data Mining and Knowledge Discovery.
  • Powder metallurgy of Titanium alloys.
  • Thermal Physics or Thermal Science.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene