Washington: Californian scientists have created a new generation of microcapsules that promise to deliver "chemicals on demand " for a wide range of uses, including medicine and personal care.
The microcapsules are used in carbon-free copy paper, in which capsules burst and release ink with pressure from a pen.
They burst when exposed to light and release their contents in ways that could have wide-ranging commercial uses from home and personal care to medicine.
Jean Frechet, Alex Zettl and colleagues have noted that liquid-filled microcapsules have many other uses, including self-healing plastics.
The plastics contain one group of microscapsules filled with monomer and another with a catalyst.
When scratches rip open the capsules, the contents flow, mix, and form a seal.
Scientists have said that microcapsules that burst open when exposed to light would have great advantages.
Light could be focused to a pinpoint to kill cancer cells, for instance, or shined over a large area to print a pattern.
The new microcapsules consist of nylon spheres about the size of a grain of sand.
They enclose a liquid chemical sprinkled with carbon nanotubes. The nanotubes convert laser light to heat that bursts the nylon capsule, releasing the chemical.
Using such a system, doctors, for example, might inject microcapsules containing anti-cancer drugs to specific cells and make the capsules burst upon exposure to laser light, delivering their contents precisely where and when they are needed in the body.
The study appears in the Journal of the American Chemical Society, a weekly publication.
ANI
First Published: Thursday, October 29, 2009, 16:34