Calcium phosphate-encapsulated silver powder

✍ Scribed by Aleksey N. Vasiliev; Eugene Zlotnikov; Richard E. Riman

• Book ID: 104094455
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 462 KB
• Volume: 203
• Category: Article
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2008.10.028

✦ Synopsis

Calcium phosphate encapsulated silver powder was obtained by heterogeneous nucleation during treatments of dispersed silver first with solutions of Ca(NO 3 ) 2 and then with Na 2 HPO 4 . Before treatment silver powders were functionalized with 3-mercaptopropionic acid and dispersed in a precipitation medium so the carboxylate groups could serve as nucleation sites. The ratio Ca/P in the coating increases with the number of treatment cycles. In contrast, calcium phosphate precipitation by slow release of phosphate ions via hydrolysis of tri(4-nitrophenyl)phosphate in a solution of Ca(NO 3 ) 2 results in homogeneous nucleation only; coating does not form on silver particles.