NIRT- GOALI: Solution-Based Dispersion, Sorting, and Placement of Carbon Nanotubes

This proposal was received in response to Nanoscale Science and Engineering initiative, NSF05-610, category NIRT. The objective of the research is to develop and study solution-based methods for dispersion, sorting, and placement of carbon nanotubes. The approach is based on the formation of hybrids of carbon nanotubes with DNA that have proven to be effective dispersants, have the ability to separate nanotubes, and result in a dispersion of charged colloidal particles that allow the development of placement techniques. The overall goals are to develop the ability to:

1) Place carbon nanotubes at a given location on a substrate with prescribed density and orientation.

2) Sort a heterogeneous sample of carbon nanotubes into all its constituent types.

3) Design experimental conditions for controlled placement and separation.

4) Predict structure of carbon nanotube/DNA hybrids.

Because of their superlative electrical and mechanical properties, carbon nanotubes have great potential for use in applications as varied as strengthening elements in composites, semiconducting channels in nanoelectronics, and as biosensors. Perhaps the biggest obstacle in the way of realizing this potential is the difficulty in processing them, especially via a solution route. Critical problems are effective dispersion, sorting according to length, diameter, and electronic character, and controlled placement on a substrate. If effective ways are found to process carbon nanotubes, it will result in the development of new materials and devices with significant economic and health benefits. Study of the underlying phenomena required for successful work on this problem will require us to tackle several fundamental problems in nanoscale science and engineering. Graduate and undergraduate students participating in the program will be educated in highly interdisciplinary research including biological sciences, chemical engineering, mechanics, physics, and materials science.