a
Institut Européen des Membranes – ENSCM-UMII-CNRS 5635, Place Eugène Bataillon, CC 047, F-34095 Montpellier, Cedex 5, France
E-mail: mihai.barboiu@iemm.univ-montp2.fr
b
University “Politehnica” of Bucharest, Department of Inorganic Chemistry, 1, Polizu st., RO-011061 Bucharest, Romania