Hi Alham,

Probe sonication is a good technique to avoid the agglomeration of nanoparticles. As you say that you  have prepared mono-disperse spherical silver nanoparticles of size around 45 nm on average. You don't need to do much sonication. You can work at 98 % amplitude and 20 kHz frequency. Time and amplitude, both are the key factors which changes the properties of materials. Yo can set the probe to operate 8 sec and standby for 2 sec during the 5 min processing time to avoid excessive heating and damage to your sonicator.

Hopefully this may help you.

Thank you so much Mr. Kumar

I want the protocol plz for silver nano disperse