[lab-rat]

Hi there.

Am having a lot of trouble cleaning NaYF4:Yb/ Er upconversion nanoparticles which have been synthesized in a 1-octadecene solvent using an oleic acid stabilizer. In literature, the last stage of synthesis is done under an inert atmosphere to prevent the oleic acid from oxidizing at 300 degrees Celsius. This is supposed to produce light brown to white particles which are easily cleaned (with methanol) and dried. Originally, I followed the literature method including the last heating step under inert gas, used dry solvents etc etc, however, the yields were extremely low. I then had to swap one of the reagents, yttrium tri chloride, for a nitrate salt. For some reason this caused the oleic acid to oxidize at lower temperatures and it produced better yields. The only problem is that the final product is so sticky that its extremely difficult to clean and dry. I have tried to dissolve the particles in hexane and precipitate them out with ethanol/ methanol but this doesn't always work. I'm working with low yields as it is and every time this doesn't work out I have to start over. Its also part of a multi stage conjugate synthesis so I really really need this to work. Please please help. Any advice would be much appreciated. 

[Cgd1287]

New to the forums and this post is a few months old, but I did some work on upconverting NaYF₄:Er³⁺/Yb³⁺ and NaYF4:Tm³⁺/Yb³⁺ if you are still interested