Browsing by Author "Flatt, Austen K."

Now showing 1 - 3 of 3
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    Bulk separation of carbon nanotubes by bandgap
    (2011-05-10) Tour, James M.; Dyke, Christopher A.; Flatt, Austen K.; Rice University; United States Patent and Trademark Office
    The present invention is directed to methods of separating carbon nanotubes (CNTs) by their electronic type (e.g., metallic, semi-metallic, and semiconducting). Perhaps most generally, in some embodiments, the present invention is directed to methods of separating CNTs by bandgap, wherein such separation is effected by interacting the CNTs with a surface such that the surface interacts differentially with the CNTs on the basis of their bandgap, or lack thereof. In some embodiments, such methods can allow for such separations to be carried out in bulk quantities.
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    Metal-free silicon-molecule-nanotube testbed and memory device
    (2010-04-27) Tour, James M.; He, Jianli; Chen, Bo; Flatt, Austen K.; Stephenson, Jason J.; Doyle, Condell D.; Rice University; United States Patent and Trademark Office
    Work from several laboratories has shown that metal nanofilaments cause problems in some molecular electronics testbeds. A new testbed for exploring the electrical properties of single molecules has been developed to eliminate the possibility of metal nanofilament formation and to ensure that molecular effects are measured. This metal-free system uses single-crystal silicon and single-walled carbon nanotubes as electrodes for the molecular monolayer. A direct Si-arylcarbon grafting method is used. Use of this structure with π-conjugated organic molecules results in a hysteresis loop with current-voltage measurements that are useful for an electronic memory device. The memory is non-volatile for more than 3 days, non-destructive for more than 1,000 reading operations and capable of more than 1,000 write-erase cycles before device breakdown. Devices without π-conjugated molecules (Si—H surface only) or with long-chain alkyl-bearing molecules produced no hysteresis, indicating that the observed memory effect is molecularly relevant.
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    Methods of attaching or grafting carbon nanotubes to silicon surfaces and composite structures derived therefrom
    (2012-04-17) Tour, James M.; Chen, Bo; Flatt, Austen K.; Stewart, Michael P.; Dyke, Christopher A.; Maya, Francisco; Rice University; United States Patent and Trademark Office
    The present invention is directed toward methods of attaching or grafting carbon nanotubes (CNTs) to silicon surfaces. In some embodiments, such attaching or grafting occurs via functional groups on either or both of the CNTs and silicon surface. In some embodiments, the methods of the present invention include: (1) reacting a silicon surface with a functionalizing agent (such as oligo(phenylene ethynylene)) to form a functionalized silicon surface; (2) dispersing a quantity of CNTs in a solvent to form dispersed CNTs; and (3) reacting the functionalized silicon surface with the dispersed CNTs. The present invention is also directed to the novel compositions produced by such methods.