Self-assembled nanostructured polymer films from concentrated solutions of block copolymers

摘要

We are presenting in this paper a simple method to orient auto-assembling systems. We detail the production process of oriented nanostructured polymer films by shearing a concentrated solution of block copolymers. The most appropriate tool to simulate the applied strains during the film formation is a rheometer with a cone-plate geometry. We use the technique of Small Angle X-ray Scattering (SAXS) on the high brilliance beamline ID02 of the European Synchrotron Radiation Facility (ESRF) to analyse in situ the structure at large scale. By coupling on-line rheology with SAXS (Rheo-SAXS), we can determine simultaneously the structure and its stability associated with the shear rate. Hence, the solution is spread using a film applicator within the same mechanical strain deformation scheme. Once dried, films are observed by SAXS. Finally, a detailed analysis of orientation distribution function obtained from the SAXS diffusion pattern on each film provides a quantitative value of the level of alignment of the polymeric chains.