1. Division of Materials Science; Luleå University of Technology; Luleå 97187 Sweden
2. Learning Institute; King Mongkut's University of Technology Thonburi; Bangkok 10140 Thailand
3. Nanotec-KMUTT Center of Excellence on Hybrid Nanomaterials for Alternative Energy; King Mongkut's University of Technology Thonburi; Bangkok 10140 Thailand
4. Fibre and Particle Engineering; University of Oulu; Oulu FI-91400 Finland