1. Institut für Mikrotechnik Mainz GmbH, Chemical Micro and Milli Process Technologies, Carl-Zeiss-Strasse 18-20, 55129 Mainz, Germany, Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Den Dolech 2, 5600 MB Eindhoven, The Netherlands, and Friedrich Schiller University of Jena, Technical Chemistry and Environmental Chemistry, Lessingstrasse 12, 07743 Jena, Germany