Shear and Extensional Rheology of Carbon Nanofibers in Polymer Melts Jianhua Xu1, Kurt W. Koelling1,

1
Shear and Extensional Rheology of Carbon
Nanofibers in Polymer MeltsJianhua Xu1, Kurt W.
Koelling1, Yingru Wang1, Stephen E. Bechtel1,
Greg Forest2 1Ohio State University,
2University of North Carolina - Chapel Hill

• Significant Results
• Inclusion of carbon nanofibers in an amorphous
  thermoplastic polymer greatly increases the
  elastic and viscous moduli, but does not affect
  the mobility of the polymer chains
• Developed thermomechanical models that couples
  the 3D CNF orientation with the measured
  rheological properties
• Constructed explicit bridges between the
  composites process induced nanostructure and
  bulk performance properties

• Research Objectives
• Create a comprehensive rheological and structural
  characterization of nanoclays and nanotubes in
  polymer melts and solutions
• Create a predictive multi-scale characterization
  which couples processing to the development of
  the performance properties of the polymer
  nanocomposites, combing theory, modeling and
  experiment
• From this characterization and modeling develop
  simulation tools for the control and optimization
  of processes for new polymer composites with
  enhanced performance

• Carbon nanofiber/polymer system

• Approach
• Optimize the dispersion of solid nanofibers in
  polymer solutions
• and melts
• Measure the coupling of rheology and nano-scale
  structure
• development in these polymer/nanoparticle
  composites for
• steady shear, oscillatory shear, and
  elongational flows
• Measure temperature dependence
• Develop models which predict the observed flow
  behavior and
• evolution of structure
• Exploit our measurements and modeling to create
  computational
• tools for processing new polymer composites

Nanoparticle dispersion
Effect on rheology

• Broader Impact
• The experiments and modeling of this project will
  allow for the creation of new materials and
  devices with powerful new capabilities, due to
  the tailoring of nano-scale structure to meet
  performance demands

Predicted performance
Flow induced orientation