Microcapsule mix

Chemical engineers from Rice University have developed a fundamentally new approach for making tiny hollow spheres called microcapsules.

Microcapsule research is one of the most active fields in applied nanotechnology, with dozens of companies either developing or using the tiny containers - usually smaller than living cells - to deliver everything from drugs and imaging agents to perfumes and flavour enhancers.

In research appearing in this month's issue of the journal Advanced Materials, Michael Wong and his research group describe an approach for making microcapsules that involves mixing a solution of polymer and salt with tiny particles of silica that contain just a few hundred atoms apiece.

Microcapsules are typically made by depositing layers of a coating onto a template or core, which has to be removed to form the hollow centre of the structure. The core is usually burned out with high heat processes or dissolved with harsh chemicals. Both processes can damage both the microcapsules and their cargo.