BEH. 462/3.962J Molecular Principles of Biomaterials Spring 2003 Pourbaix diagram thermodynamic stability 12 Au(OH)3 C E/VO 4 45 M NaCI solution resents the kinetics of the gold corrosion reaction in choride containing 24681012m WHY DOES GOLD DISSOLVE AT PH 7? POURBAIX DIAGRAM SHOWS OXIDE IS STABLE FORM Figure 4. Photographs of a prototype ining front side, b)the back side e microchip. a) The electrode servoirs( Scale bar: 10 mm; photographs by Paul Horwitz. · Release properties Figure 7. ng electron micrographs of a gold covering a reservoir a) before and b) after the applicat +1.04 V vs SCE for seconds in phosphate-buffered saline and that ofCa(e)in units of 5na min". I in day Lecture 5- Programmed Drug Delivery 6 of 12BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 Pourbaix diagram: thermodynamic stability 1.6 1.2 0.8 E/V0.4 0.0 -0.4 -0.8 -1.2 [AuCl4] ­ Au(OH)3 2 4 6 8 10 12 Au pH • WHY DOES GOLD DISSOLVE AT PH 7? POURBAIX DIAGRAM SHOWS OXIDE IS STABLE FORM (Cima work) 6 • Release properties: Lecture 5 – Programmed Drug Delivery 6 of 12