i used ascorbic acid as stabilizing agent and sugar as reducing agent i try variable ratios of metal ligand and ascorbic acid and vaying ph for stability but fail to stabilize after 4 hour of synthesis the of nanoparticles which are orange beomes change to orangish brown and peak becomes diminish i tried ph up to 13.8
first I mix metal ligand and ascobic acid stir and heat solution for 15 minutes cool solution then maintain ph up to 13.8 (the nps synthesize ph between 11.5-13.8) during maintaing Ph the color of the solution changes to dark yellow stir the solution up to 10 minutes the colour changes to orange the wavelength between 500-510nm. file is attach i dont to change my ligand plz give valueable suggestion
Copper has a high density (~ 9.3 g/cm3). Your first task is to carry out a Stokes' law calculation to determine what size the particles need to be to remain in colloidal suspension (i.e. will not settle after 14 days). Stabilization can be with charge ('electrostatic') or steric (polymer). At these pH's I do not believe that you can affect the charge stability much. Note that pH is spelled thus - you discredit your text when you get such a thing wrong. Look at:
February 18th, 2016 Metal colloids - their preparation, application and characterization
https://www.brainshark.com/malvern/vu?pi=529368070&b=1&tx=120486&c1=22
Nov 11th, 2008. Dispersion and nanotechnology http://tinyurl.com/hpywsge
I'd be looking to reduce the pH at the preparation stage (only in basic systems will Cu(OH)2 precipitate) and stabilize the system sterically with a PEG or PEI of 50 kDa or so. Be aware that, in air, the surface of your particles (XPS/ESCA) is copper oxide and not copper.
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