1. Department of Materials Science, Faculty of Science; Chulalongkorn University; Bangkok 10330 Thailand
2. Center of Excellence on Petrochemical and Materials Technology; Bangkok 10330 Thailand
3. National Metal and Materials Technology Center; National Science and Technology Development Agency; Pathum Thani 12120 Thailand
4. National Nanotechnology Center National Science and Technology Development Agency; Pathum Thani 12120 Thailand