1. Institute of Chemical Engineering and Environmental Technology, Graz University of Technology, NAWI Graz, Inffeldgasse 25C, Graz 8010, Austria
2. Chemical Engineering Department, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Malaysia
3. Institute for Electron Microscopy and Nanoanalysis and Center for Electron Microscopy, Graz University of Technology, NAWI Graz, Steyrergasse 17, Graz 8010, Austria