Charge interaction effects in epoxy with cation exchanged montmorillonite clay and carbon nanotubes.

Description:

The influence of charge heterogeneity in nanoparticles such as montmorillonite layered silicates (MLS) and hybrid systems of MLS + carbon nanotubes was investigated in cured and uncured epoxy. Epoxy nanocomposites made with cation-exchanged montmorillonite clay were found to form agglomerates near a critical concentration. Using differential scanning calorimetry it was determined that the mixing temperature of the epoxy + MLS mixture prior to the addition of the curing agent critically influenced the formation of the agglomerate. Cured epoxy samples showed evidence of the agglomerate being residual charge driven by maxima and minima in the concentration profiles of thermal conductivity and dielectric permittivity respectively. A hybrid nanocomposite of MLS and aniline functionalized multi walled nanotubes indicated no agglomerates. The influence of environmentally and process driven properties on the nanocomposites was investigated by examination of moisture, ultrasound, microwaves and mechanical fatigue on the properties of the hybrid systems. The results point to the importance of charge screening by adsorbed or reacted water and on nanoparticulates.

Creator(s): Butzloff, Peter Robert
Creation Date: May 2005
Partner(s):
UNT Libraries
Collection(s):
UNT Theses and Dissertations
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Total Uses: 313
Past 30 days: 7
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Publisher Info:
Publisher Name: University of North Texas
Place of Publication: Denton, Texas
Date(s):
  • Creation: May 2005
  • Digitized: February 6, 2008
Description:

The influence of charge heterogeneity in nanoparticles such as montmorillonite layered silicates (MLS) and hybrid systems of MLS + carbon nanotubes was investigated in cured and uncured epoxy. Epoxy nanocomposites made with cation-exchanged montmorillonite clay were found to form agglomerates near a critical concentration. Using differential scanning calorimetry it was determined that the mixing temperature of the epoxy + MLS mixture prior to the addition of the curing agent critically influenced the formation of the agglomerate. Cured epoxy samples showed evidence of the agglomerate being residual charge driven by maxima and minima in the concentration profiles of thermal conductivity and dielectric permittivity respectively. A hybrid nanocomposite of MLS and aniline functionalized multi walled nanotubes indicated no agglomerates. The influence of environmentally and process driven properties on the nanocomposites was investigated by examination of moisture, ultrasound, microwaves and mechanical fatigue on the properties of the hybrid systems. The results point to the importance of charge screening by adsorbed or reacted water and on nanoparticulates.

Degree:
Level: Doctoral
Discipline: Materials Science
Language(s):
Subject(s):
Keyword(s): montmorillonite clay | carbon nanotubes | charge effects
Contributor(s):
Partner:
UNT Libraries
Collection:
UNT Theses and Dissertations
Identifier:
  • OCLC: 61850682 |
  • ARK: ark:/67531/metadc4786
Resource Type: Thesis or Dissertation
Format: Text
Rights:
Access: Public
License: Copyright
Holder: Butzloff, Peter Robert
Statement: Copyright is held by the author, unless otherwise noted. All rights reserved.