Historical background

Janus particles are dissymmetric particles named in reference to the Roman god Janus, usually represented with one head but two faces. Janus particles are micro- or nano-objects with two sides having different properties.

A new process developed in our group can modify any conductive object, from micrometer to sub-micrometer scale with a large spectrum of materials to form a dissymmetric particle. For example, a particle may have both hydrophilic and hydrophobic properties.

This unique feature allows the fabrication of micro or nano-objects comprising two regions of different polarity or chemical activity. There is an increase of scientific and industrial interest in such Janus particles. Such particles can be used in a wide range of applications like catalysis, therapeutic treatments, textiles, food processing, sensors, imaging… Unfortunately, because of their unique architecture, the synthesis of Janus particles remains a challenge.

The process

The technology is based on a patent filed at the end of 2010 by the University Bordeaux I, the Polytechnic Institute of Bordeaux and the CNRS (National Center for Scientific Research). Our group was firstly able to develop a laboratory reactor which produces quantities of these Janus particles covered with metal, carbon or conductive polymers at the milligram-scale. The team then proceeded to manufacture a prototype to obtain production at a larger scale.