1. Tyndall National Institute, University College Cork, Lee Maltings Complex, Dyke Parade, Cork T12R5CP, Ireland
2. Institute for Polymers, Composites and Biomaterials, National Research Council of Italy, P.le E. Fermi 1, 80055 Portici, Italy
3. Institute for Polymers Composites and Biomaterials, National Research Council of Italy, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
4. Institute for the Study of Nanostructured Materials, National Research Council, Monterotondo Staz., 00015 Rome, Italy