1. Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, U.K., Department of Chemical Engineering and CERSIM, Laval University, Québec, Canada, G1K 7P4, and Center for Education and Research on Macromolecules, University of Liège, Sart-Tilman B6, 4000 Liège, Belgium