“Our starting point is to develop approaches to control the synthesis of carbon nanotubes,” said Dai, a physical chemist at Stanford University. “We think we have some very original ideas.”
Nanotubes, a new form of carbon discovered in 1989, have intrigued chemists and other scientists because of their unusual properties. Their structures can be up to 100 times stronger than steel and may act like either semiconductors or metals, depending on their makeup. Individual nanotubes can reach several millimeters long — and that, combined with their ability to conduct electricity, could make them ideal molecular “wires.”
To study how chemical makeup and properties relate to each other, researchers need to control their synthesis, or the assembly of their structures. Dai and his research team have designed a system that builds nanotubes piece by piece, anchoring and organizing them on a surface instead of allowing them to form randomly.
One type of nanotube structure he has built shows promise as a sensor to pick up the presence of nitrogen dioxide, a pollutant in the exhaust of badly tuned automobiles. “When nitrogen dioxide lands on this carbon nanotube it pulls electrons away from it,” he explained. “That changes the nanotube’s electrical conductance, and we can detect that change.”
A native of China, Dai “grew up as a kid interested in physics,” he said, and indeed obtained a Ph.D. in the field. “Then I realized as I grew older that chemistry is very necessary to make materials that have interesting properties to study, so I followed that direction.”
Dai received his undergraduate degree from Beijing's TsingHua University in 1989 and his Ph.D. from Harvard University in 1994. He is a member of the ACS division of physical chemistry.
The ACS Award in Pure Chemistry is sponsored by Alpha Chi Sigma Fraternity.