Modeling the pipeline of high performance, nano-composite materials and effective properties, II

Acknowledgements

Slide 3



The nematic polymer, nano-composite, high performance materials pipeline.

Nematic Polymer, Nano-Composite Effective Electric Conductivity

Forget resolving the actual Nano-Composite Elliptic Problem….. Σ(x) is simply not computable, so
Homogenize up to Effective Conductivity

Homogenization formula in low volume fraction limit of spheroidal inclusions (analogous formulas for thermal and dielectric properties)

Geometry of nano-inclusions
allows explicit evaluation of the integrals

 Exact scaling laws of effective electrical conductivity  tensor

Anisotropic conductivity enhancements

Finer scaling properties require ordering of two inherent asymptotic parameters of nano-composites:            high aspect ratio vs. high conductivity contrast

Hierarchy of materials & property predictions for nematic polymer nano-composites

Property inheritance of hysteresis & bistability
of monodomains at rest and after shearing

Slide 14

Extension-induced bulk phases:  Effective conductivity   vs. vol %, uniaxial & biaxial  extension  (Zhou et al. Macro. Symposia ’05)

Fiber effective conductivity vs final radius
(equiv., 1/takeup speed in fiber process)

Oscillating conductivity in simple shear vs shear rate:  inheritance of strong pdf shape distortions at T/W transition

Slide 18

Slide 19

Molecular morphology & rheology
 in confined film flows:  strong elasticity limit

Slide 21

Slide 22

Slide 23

Transfer database for the molecular pdf to effective conductivity principal value thru the film:
flashing local “conductivity voids” near defect structures

Nano-Composite Property Fluctuations and Heterogeneity During Steady Film Processing

Nano-Composite Property Fluctuations and Heterogeneity During Steady Film Processing

Slide 27

Slide 28

Slide 29



What roles do these dynamic structures play in multifunctional material properties?

"Underlying these technological applications is..."