... DOI: 10.1039/B925831K (Paper) J. Mater ... ewha.ac.kr; Fax: + 82 2 3277 4340; Tel: +82 2 3277 4135 c Department of Chemistry and Medical Chemistry, College of ... added, and the pellets were incubated for 20 min at 4 °C followed by ultrasonication for 20 s. (Sonics & Materials Inc ...