1. LBMI, Department of Physics; Lebanese University, Faculty of Sciences II; PO Box 90656 Jdeidet Lebanon
2. Department of Chemistry; Lebanese University, Faculty of Sciences II; PO Box 90656 Jdeidet Lebanon
3. Institut Européen des Membranes (IEM-UMR ENSCM-UM2-CNRS 5635); Université Montpellier 2 (CC 47); Place Eugene Bataillon 34095 Montpellier cedex 5 France