1. Solution-Based Dispersion, Sorting, and Placement of Carbon Nanotubes (NIRT/GOALI)
A. Jagota*, M. Zheng#, Y-M. Chiang+, S.V. Rotkin*, C. Kiely* (PI’s; Program Officer: Jimmy K. Hsia)
W.C. Carter+, R.S. McLean#, C-Y. S. Lustig#, R.H. French#, T. Tang&
C. Khripin*, R. Rajter+, S. Snyder*, S. Suresh*, Deping Xue*
*Lehigh University; #DuPont; University; &University of Alberta
Solution Based Processing of Carbon Nanotubes
Separation by Anion Exchange Chromatography
Optical properties
of single-wall nanotube DNA hybrids
Design of New Ion-Exchange Resins
Band strucure of DNA-wrapped SWNTs
Numerical method for modeling symmetry lowering in DNA-SWNT hybrids.
Self-consistent charge density
Polarization interaction between the DNA phosphate groups and the induced (self- consistent) charge on the SWNT
Helical symmetry-breaking results - appearance of intrinsically forbidden optical transitions in perpendicular polarization.
Symmetry-breaking is predicted to result in strong circular dichroism.
Strategy: Control of
Pore structure;
Polymer ion-exchange chain length and density;
Hydrophobicity.
Non-porous polystyrene/divinyl benzene (PS/DVB) particles as the substrate for synthesizing ion-exchangers.
Raw Material Applications
Goals
Place carbon nanotubes at a given location on a substrate with prescribed density and orientation.
Sort a heterogeneous sample of carbon nanotubes into all its constituent types.
Design experimental conditions for controlled placement and separation.
Predict DNA-CNT structure given DNA sequence and CNT type.
Zheng & Semke, JACS (2007) ,
Vadim Puller and Slava V. Rotkin, Europhysics Letters 77 (2), (Jan 2007).
Stacy E. Snyder and Slava V. Rotkin, JETP Letters 84 (6), , (Pis'ma v ZhETF 84 (6), ), (2006).
Alexey G. Petrov, Slava V. Rotkin, JETP Letters 84 (3), (Pis'ma v ZhETF 84 (3), ), (2006).
Vadim Puller, and Slava V. Rotkin, in Nanomodeling, Akhlesh Lakhtakia, Sergey A. Maksimenko, Editors; Proceedings of SPIE, vol. 6328, 63280D, 2006.
T. Tang, A. Jagota, Journal of Computational and Theoretical Nanotechnology accepted (2007).
What governs adhesion between DNA & a CNT? Is there an optimal wrapping geometry?
van der Waals interactions of CNT’s
Deposition and Alignment
+ (ns)
Meniscus Alignment
Several Bases Un-Stack
Contributing Terms in the formation of hybrid:
Adhesion
Entropy loss of DNA backbone
Electrostatics
Bending and torsion of DNA backbone
Deformation of CNT
Base-Base Stacking
Hydrogen bonding
Case I
Case II
Unstacked BAse
Stacked Base
Liquid Crystal Hypothesis
Minimized
Equilibrated at 300K
Reduction of Effective Adhesion Energy
free energy density
R.F. Rajter et al. Journal of Applied Physics (2007).
R.F. Rajter et al. Physical Review B (2007).
R.S. McLean et al. Nanoletters, 6 [1] (2006)
C. Khripin, A. Jagota, T. Tang J. Phys. Chem. B (in the press)
S. Manohar, Tian Tang, Anand Jagota, J. Phys. Chem. B, (2007)