1. Physical Chemistry 1, Center for Chemistry and Chemical Engineering, Lund University, Box 124, S-221 00 Lund, Sweden; IFP Research, Swedish Institute for Fiber and Polymer Research, Box 104, S-431 22 Mölndal, Sweden; and Van't Hoff Laboratory of Physical and Colloid Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands