Improved Nitroxide Mediated Photo-Polymerization Process : An unique tool to combine Surface Micropatterning and Tailored Polymer Properties – IMPACT

Photopolymers and in particular surface patterning has become an increasingly important part in modern science and technology, such as in the areas of micro-electronics, information processing and storage, nano/microfluidic devices, and biodetection. The aim of this project is then to develop a straightforward methodology based on light sensitive alkoxyamines to prepare such micropatterns, with the advantage to have the possibility of reinitiate the polymerization of a second monomer. In that case multi-layered covalently-linked micropatterns could be prepared. We will then study in details the mechanism of the UV-induced dissociation of such alkoxyamine to find the optimized compound able to control the photopolymerization both spatially and structurally (i. e. the chain length and the end chain functionality).
In 2008, we envisioned to develop new light sensitive alkoxyamines as photoinitiating systems for a Controlled Radical PhotoPolymerization Process called Nitroxide Mediated PhotoPolymerization (NMP2). This short-term 2-years project finally leads to 5 publications. Nevertheless these short-term studies allow us only to test few compounds and have a rough idea of the structures, which lead to an efficient NMP2 process. Despite these first results, important works remain to improve the NMP2 process. This is crucial to keep the leadership on this topic to both optimize the system and in the same time test its potential in micropatterning. Indeed, in recent years, fabrication of chemical and topographical functional materials in the micrometer and nanometer scales has been drawing a great interest in the scientific community. The attention is not only due to the need for ever-increasing miniaturization of microelectronics for example, but also because of the discovery of many novel phenomena that occur at these scale levels. The size of the patterns is strongly dependent on the technique used and can range from micrometer to sub-10 nanometer scale. In particular, we are exploring significant advances in the following fields: microfluidic, superhydrophobic surfaces, optics/photonics and biology. Indeed the final objective to this new project is to associate controlled radical photopolymerization and photolithographic methods to pattern functional polymer materials.