1. Department of Chemical Engineering, University College London, Torrington Place, London WC1 7JE, U.K.
2. Clariant GmbH, Division Pigments & Additives, SU Technology & Innovation Management, Process Development/Pilot Plants, Clariant Competence Center Micro Reaction Technology C3-MRT, Industriepark Höchst G835, D-65926 Frankfurt am Main, Germany
3. Institut für Mikrotechnik Mainz, Carl Zeiss Strasse 18−20, D-55129 Mainz, Germany