Week 11: Last Week

I tested synthesis of nZVI using high pH borohydride solution. The reason for this test is that the BH4 can react with water while it is being "waited" to be added to the synthesis chamber. The reaction process includes a equilibrium where OH is produced. Thus, if we increase pH, it is possible to "stop" the BH4 from reacting with water. When I tested, the minimum pH to stop BH4 from reacting with water was ~pH 12-13. I went ahead and synthesized FeCMC-BH. It failed, as the nZVI formed was not nanosized; it was in mm~cm rather than nm in size.

Possible reasons why it failed:
CMC has carboxy group, and if CMC-Fe complexation involves partial charges of that carboxy group (most likely), it is possible that introduction of OH can alter the existing charges on CMC by deprotonating carboxylic acid or by deprotonating the alpha-hydrogens.

Today is my last day at the internship. I will be doing my final presentation in two hours. It's been fun and challenging summer.
Thanks to Dr. Jim Nurmi, Dr. Johnson, Dr.Tratnyek, everyone in Tratnyek lab, and Vanessa Green. Thanks to everyone who helped me, watched me, or even read me. Feel free to e-mail me at tl354@cornell.edu or taewonlim@gmail.com.                
-Paul Lim-