University of Michigan researchers have discovered a way to make nanocrystals in a fluid assemble into free-floating sheets the same way some protein structures form in living organisms.
"This establishes an important connection between two basic building blocks in biology and nanotechnology, that is, proteins and nanoparticles, and this is very exciting for assembling materials from the bottom up for a whole slew of applications ranging from drug delivery to energy," said Sharon Glotzer, professor of chemical engineering and materials science and engineering.
Glotzer and Nicholas Kotov, associate professor of chemical engineering, and their graduate students and post doctoral researchers have co-authored a paper scheduled to appear Oct. 13 in the journal Science.
"The importance of this work is in making a key connection between the world of proteins and the world of nanotechnology" Kotov said. "Once we know how to manipulate the forces between the nanoparticles and their ability to self-organize, it will help us in a variety of practical applications from light-harvesting nanoparticle devices to new drugs which can act like proteins, but are actually nanoparticles."
The sheets, which can appear colored under UV illumination from bright green to dark red depending on the nanoparticle size, are made from cadmium telluride crystals, a material used in solar cells. The sheets are about 2 microns in width, about 1/5 the thickness of a human hair.
Scientists have long known how to coax nanoparticles into forming sheets, Glotzer said. But those sheets have only been achieved when the particles were on a surface or at an interface between two fluids, never while suspended in a single fluid.
The work started in Kotov's lab three years ago, when he and his team observed the sheets in experiments. Though th
Source:University of Michigan