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Structure of twisted BNC nanotubes with polygonal cross-section
Vladimir Blank1, Leonid Ivanov, Boris Kulnitskiy
1Technological Institute for Superhard and Novel Carbon Materials (TISNCM), Troitsk, Moscow Region, Russian Federation.
Acta Crystallographica. Section B, Structural Science
|September 21, 2012
Summary
Boron nitride (BN) nanotubes and nanofibers were synthesized under high pressure and temperature. TEM analysis revealed twisted, prismatic structures composed of misoriented BN and/or C plates, with Al(2)O(3) filling affecting their mechanical properties.
Area of Science:
- Materials Science
- Nanotechnology
- Solid State Chemistry
Background:
- Boron nitride (BN) nanotubes and nanofibers are advanced nanomaterials with unique properties.
- Understanding their synthesis and structural characteristics is crucial for potential applications.
Purpose of the Study:
- To synthesize BN nanotubes and nanofibers under specific high-pressure and high-temperature conditions.
- To characterize the morphology, structure, and mechanical behavior of the synthesized BN nanostructures.
- To investigate the effect of Al(2)O(3) filling on nanotube properties.
Main Methods:
- Synthesis using a high isostatic pressure apparatus at 1923 K and 1.5 MPa in Argon atmosphere with yttrium aluminum garnet.
- Transmission Electron Microscopy (TEM) for structural and morphological analysis.
- Analysis of moiré fringes to determine facet orientation and composition.
Main Results:
- Successfully synthesized BN nanotubes and nanofibers with polygonal (prismatic) cross-sections.
- Observed frequent twisting in nanostructures attributed to transversal instability during growth and thermal treatment.
- TEM analysis of moiré fringes indicated facets composed of slightly misoriented hexagonal BN and/or C plates.
- Al(2)O(3) filling was observed in some nanotubes, which increased resistance to twisting, aligning with tube deformation theory.
Conclusions:
- High-pressure, high-temperature synthesis is effective for producing BN nanotubes and nanofibers.
- The observed twisting is an intrinsic characteristic influenced by growth conditions and material instability.
- The structural analysis provides insights into the fundamental properties of BN nanostructures.
- Al(2)O(3) filling demonstrates a quantifiable impact on the mechanical response of BN nanotubes.
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