November 25, 2008: Research chemists at the University of Warwick have devised an process that cheaply covers small particles of polymer with a layer of silica-based nanoparticles. The final result provides a highly versatile material that can be used to create a range of high performance materials, such as self-healing paints, and clever packaging that can be tailored to let precise levels of water, air, or both pass in a particular direction.

The research, led by Stefan Bon of Warwick’s Department of Chemistry, has created a “soap-free emulsion polymerization process” which makes colloid particles of polymer dispersed in water and in one simple step introduces nanometer-sized silica based particles to the mix. These silica-based nanoparticles (about 25nm in size) coat the polymer colloids with a layer, “battering” it like a fish battered in breadcrumbs.

This process creates a very versatile polymer latex product. Application examples include scratch-resistant paints in which the scratches heal themselves; also, polymer-based packaging which will allow water or air to pass through the packaging in tailored ways. The resultant rough textured spherical shapes also lend themselves to the creation of sheets with polymer that present much more surface area than usual allowing more efficient interaction with other materials.

This new process can already be produced on a mass scale with currently used industrial equipment, the researchers claim.

A multi-layered polymer colloid taken with a transmission electron microscope.