Good question. I think this is going to take a lot of experimentation to really gauge the effect of frequency and intensity. Because the energetics of a cavitation event in an ultrasonic field is going to vary with every changing parameter. There are times when the particle sizes I obtained after 30 mins. and 90 mins. of sonication at the same frequency has been near about the same. What I initially expected was that after 90 mins. I would have atleast a slight decrease in the size of my nanoparticles. But since that did not happen, it hinted at a major aspect that the total energy input just wasn't enough. So you change the frequency and you indeed see the difference. You will have to exploit the extreme conditions that are generated during the process of cavitation to understand the effect of frequency, time, temperature, intensity and other parameters for synthesizing nanoparticles using ultrasonic field. I hope this helps.

Hi

I also used sonochemistry in the synthesis of nanoparticles, but I combined cycles of sonication and centrifuge. Because i used the biomass of a plant, in each cycle I add (ph, salt...)

Finally to remove the biomass I also used 3 cycles of sonication and centrifuge.

I never tried in differents times and frecuencies.

But look here are some articles that could help you

http://jcpr.kbs-lab.co.kr/file/JCPR_vol.12_2011/JCPR12-3/14.299-303_2010-83.pdf

http://www.nanoscalereslett.com/content/7/1/420

=)

Usually ultrasonic has fix frequency (20kHz). Amplitude is the amount energy transfered to creat the cavity, also need to consider theprobe, tip diameter and sample holder.

no there are variable frequencies

"Usually", of course there's a variable too, but more than 20KHz, ur tip will eroded faster.

Michael, I think it is more than 20KHz obvious, and is useful to