Gold in Sodium Tetra Bromate
At Nanotech I met a professor from Geneseo, K. Yokoyama, who worked with gold in sol-gels. He found he was able to dissolved gold in sodium tetra bromate (Na2Br4O7) without it aggregating. I have attempted to dissolve gold in other salts to no avail. This is an important step in testing membrane separations with gold, since without salts the intrinsic negative charge of the membrane will repel the gold.
I dissolved gold in 100mM sodium bromate at different pH’s. 5nm was much more stable than 10nm. Neither are stable at very low pH. Red = stable, Purple/Black = aggregated
Citrate ion pKa = 4.76
We are interested in gold because it comes in a range of sizes, but if the larger ones are not stable in this salt either, I’m not sure this is helping our cause.