1. Central Department of Chemistry, Tribhuvan University, Kathmandu, Nepal
2. Nepal Polymer Institute (NPI), PO Box 24411, Kathmandu, Nepal
3. Department of Macromolecular ChemistryUniversity of Siegen, Siegen, Germany
4. Institute for PhysicsMartin Luther University Halle-Wittenberg, Halle/Saale, Germany