French researchers create capsules that dissolve on demand

Researchers at the CNRS Paul Pascal Research Centre in Bordeaux have designed 'smart' capsules that are capable of releasing their contents on demand, simply by raising the temperature of the environment in which they are located.

The research team identified that everyday capsules are only capable of breaking the silica shell, in which they are contained, via dissolution. However, this is an entirely uncontrolled reaction. The scientists managed to overcome this lack of control by forming the capsules from an oil and silica-based emulsion in which a specific agent can be contained. The emulsion is in a liquid state at the production temperature of sixty-five degrees, but is solid at ambient temperature. In heating the temperature of the capsules' environment, the capsules return to their liquid state and break apart the silica shell in which they are enclosed.

The simple idea, which is easy to produce, can be given many applications because different types of oil change state at different temperatures. The new system could be used – amongst other things – to release perfume into the air, onto fabric or skin; to monitor the freshness of foods; or to administer a therapeutic agent to skin by rubbing, which would cause heat and make the capsules disperse.

The capsules could even be controlled to disperse at the same time or in a specific sequence. The team are now developing double emulsion systems that could extend the technique to multitherapy.

For more information on the project, contact Julien Guillaume at presse@cnrs-dir.fr

Published: Friday, 29th January 2010 by Tom Freeman

Comment on this article

Comments

No comments for this article, be the first to comment