New Mexico researchers create "smart nanostructures"

from the active-materials dept.
Researchers at Sandia National Laboratory and the University of New Mexico report they have created what they call self-assembling "intelligent nanostructures" that report on their environment by changing color from blue to fluorescent red under mechanical, chemical, or thermal stress.
According to their press release, the material can distinguish between different solvents by changing color. The material also can report changes in mechanical stress and temperature. When the environmental disturbance is removed, the structures change back to their original color in some cases, making them potentially reusable.
The Sandia/UNM fabrication method evenly pre-distributes monomers — simpler precursors of polymers — within a silica matrix through self-assembly. Exposure to UV light polymerizes the monomers into conjugated polymers housed in nanoscopic channels that penetrate the matrix of the material. The result is a nanocomposite that is mechanically robust, optically transparent, and produces telltale changes of color under changing environmental conditions. The researchers claim they also can control interactions between polymer units that affect a materialís electrical and optical properties.
Aspects of the work are also reported in the 19 April 2001 issue of Nature.