Solid State NMR Studies of Nano-materials
EMSL Project ID
1937a
Abstract
One and Two-dimensional NMR including NOESEY techniques are expected to be most effective in probing conformational changes in molecular foldamers. In contrast to the surfactant templated synthesis of mesoporous materials, the organic foldamers themselves self-assemble without templating agents. Investigation of molecular conformation and localized interactions among foldamers is necessary in order to understand the formation mechanism and associated driving forces that produce the equilibrium structures. The attractive forces between chromophores for creating folded nanostructures may be related to molecular orbital overlap ( interactions) or could be associated with hydrophobic effects. Appropriate molecular engineering of the rigid and foldable regions, will allow intramolecular interactions to be decoupled from intermolecular interactions in order to probe the conditions under which the polymer will fold before self-assembling or self-assemble before folding. 2D NMR measurements will be used to address this issue. The consequence of this outcome could be significant. If folding prevails, one can design individual foldable molecular machinery for probing formation mechanisms or use folded polymers as nanoscale building blocks for advanced materials. However, if self-assembly prevails, foldable polymer will likely form highly ordered molecular assemblies at the expense of destroying the individual character of the folded polymer. In conjunction with the magnetic resonance measurements, small-angle neutron scattering (SANS) techniques will also be used to probe inter- and intra-molecular interactions and dynamic ordering processes in these systems. SANS has been demonstrated to be a powerful tool for determining micelle structures. Accurate information about the shapes and sizes of the self-assembled foldermers determined by SANS will be correlated with the structural parameters obtained from the NMR results and with synthesis protocols.
Project Details
Project type
Capability Research
Start Date
2006-04-17
End Date
2007-05-21
Status
Closed
Released Data Link
Team
Principal Investigator