Techniques to Prepare Noble Metal Colloids

Techniques to prepare noble metal colloids Gold cluster via sodium citrate redaction method [6] 

The most well know method based on the protocol developed by Frens provides monodisperse colloidal gold. The size of the clusters can be adjusted in between 6 and 60 nm by adding varying amounts of reducing agent. 

01% (w/v) tetra-chloroauric[lIl]acid trihydrate (HAUCI4.3H2O in 100 ml of water) is heated to boiling. 

1 ml of 1 % (w/v) trisodium citrate dihydrate is added to the boiling solution under constant stirring. 

In about 25 sec the slightly yellow solution will turn into faintly blue (nucleation). 

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