In situ synthesized carbon nanotubes as a new nanostructured stationary phase for microfabricated liquid chromatographic column

We present the microfabrication of a liquid chromatographic column made out of silicon, structured by a perfectly ordered two-dimensional array of squared micropillars, and the use of in situ synthesized carbon nanotubes as a new stationary phase to increase the phase ratio of such a column. According to a collective process, a layer of nickel sputtered on the two-dimensional array of squared micropillars catalyses the growth of carbon nanotubes directly on the surface of these micropillars before the channel is sealed with anodically bonded glass cover plate. The first results describe the methodology adopted to obtain a regular coverage of the pillars surfaces with the carbon nanotubes and the possibility to implement chromatographic separations in such nanostructured microsystems in the hydrodynamic pumping mode. A comparative study in term of retention between nanostructured columns and columns only grafted with C18 alkyl chains shows that the nanostructuration with carbon nanotubes significantly increases the retention.