1. Opportunities and Barrier Issues in Carbon Nanocomposites R. Byron Pipes, NAE, IVA Goodyear Endowed Professor University of Akron National Science Foundation Composites Workshop June 9-10, 2004

2. The Future for Carbon Nanocomposites Future Trends in Technology Development Globalization of Research Barriers and Opportunities: Scale Mixing and Dispersion Multi-Functionality

3. Next Generation Aerospace Material Carbon Nanotube Nanotube/ Polymer Nanotube Fiber Ultra Nanostructured Composite

4. Connect, Click And Control

5. Factory Production Education Chemical Plant Heavy Machinery DSC TGA Polymer Industry Process Control Higher Level Research Online Microscopy Textile The Future: Connect, Click and Control

6. Carbon Nanotubes Graphene is the stiffest material known (Young’s modulus > 1 TPa) Ideal reinforcement for composite materials Single wall carbon nanotubesForms of Carbon Diamond Buckyball Graphite Nanotube 100 nm

7. SCALE Is it possible to span 12 orders of magnitude in scale and preserve properties?

8. Self Similar Helical Modeling SWCN Lattice Dymanics Nano-wire Micro- Mechanics + Self Similar Analysis Polymer Micro-fiber Micro- Mechanics + Self Similar Analysis Polymer Lamina Micro- Mechanics + Self Similar Analysis Polymer Nano-array Self Similar Analysis

9. Self-Similar Scales 1.48 x 10 -8 m. 1.68 x 10 -7 m 1.92 x 10 -6 m 1.38 x 10 -9 m SWCN SWCN Nano Array SWCN Nano Wire SWCN Micro Fiber

10. Self-Similar Scales 1.9 x 10 8 1.7 x 10 10 1.6 x 10 12 Diameter = 1.92 x 10 -6 m Length = 1.0 x 10 –3 m Number of nanotubes SWCN

11. Self-Similar Properties Carbon Fiber SWCN Nano- wire Nano- array Micro- fiber  =10°  =20° Lamina

12. Observations Nanotube – Nano Array – Nano Wire – Micro Fiber Helical array geometry provides self-similar platform 71% stiffness reduction Strength reduction may not correspond to stiffness reduction Multifunctional properties offer significant potential Use the properties at the scale of applicability

13. Mixing and Dispersion Van der Waals bonding – Energy for dispersion

14. Science 273, 483 (1996). SWCN Array Image Analysis DoDo DiDi S D o = 1.38 nm D i = 0.73 nm S = 1.48 nm Nanotube Wall Thickness = 0.33 nm Volume Fraction: Hexagonal Array = 0.79 With van der Waals = 0.906

15. Shear and Bulk Moduli x2x2 x3x3 x2x2 x3x3

16. Carbon Nanotubes Sticking Together

18. Continuum Approach for L-J Interactions r d sheet 1 atom

19. Dilatation of SWCNT Array Cohesive Energy per unit Volume

20. Dilatational Cohesive Energy per Unit Volume

21. Unit Cell Cohesive Energy ChiralityR 0, nm  0, nJ/m    GJ/m 3 (6,6)1.12810.1170.159 (10,10)1.67230.1520.207 (24,24)3.57330.2390.325

22. Conclusions for Array Flexural Properties The assumption that the CNT array can be represented as a uniform beam is not appropriate for arrays that are not fully bonded. The experimental results of Salvetat [3] for the 7- element array (4.5 nm diameter rope) with span lengths of 285 and 180 nm, revealed shearing tractions of 136 and 200 MPa, respectively. Fracture energies for SWCN fracture are significant!

23. Functionality Can multifunctionality provide the pathway for accelerated adoption? Are devices the fertile area?

24. Radial breathing mode spectra Intensity(a.u) Raman spectroscopy Higher Intensity in parallel polarization direction. Similar result seen for both two grades of CNT Orientation 0.5% nanotube(CS) composite microfiber Raman shift(cm -1 ) Tangential mode spectra