Dear Nizar,

This is a very interesting question. I must thank you for posting it. In my experience gold and silver nano particles display localized surface plasmon resonance; where the characteristic absorption frequency is acutely dependent on the size and shape of particles (given the size distribution is narrow). Hence, it might be possible to evaluate their size using UV-Vis spectroscopy. 

If that was the basis of your evaluation then in my opinion it might not be possible to extend the same principle to Fe3O4 or SiO2 as they lack LSPR. Might I suggest the use of more traditional techniques such as Zeta sizer or SEM/TEM for a more reliable analysis.

I hope it helps.

Regards

Dear Nizar,

This is a very interesting question. I must thank you for posting it. In my experience gold and silver nano particles display localized surface plasmon resonance; where the characteristic absorption frequency is acutely dependent on the size and shape of particles (given the size distribution is narrow). Hence, it might be possible to evaluate their size using UV-Vis spectroscopy. 

If that was the basis of your evaluation then in my opinion it might not be possible to extend the same principle to Fe3O4 or SiO2 as they lack LSPR. Might I suggest the use of more traditional techniques such as Zeta sizer or SEM/TEM for a more reliable analysis.

I hope it helps.

Regards

Dear Mr. Nizar,

As Mr. Chaudan already mentioned, the characterization of the size for the nanoparticles via UV-Spectroscopy can only give an estimation of their size, if you want to publish the results in a journal their will be probably reject the size distribution analysis. For the absolute, proper measurement of their size TEM analysis must be done. Also DLS can be done which can give a good size statistic analysis, the dispersion of the nanoparticles can be also studied via AFM.

Concluding, my suggestion is to stay on TEM which will give an accurate size analysis and distribution.

Regards,

G. Peppas

This is a very interesting question 

سؤال مثير للاهتمام

This is a very interesting question

ان التردداد الامتصاصيه تعتمد على الشكل والحجم الحبيبه  لذلك من الممكن نحسب حجم باستخدام مطياف الاشعه الفوق البنفسجيه 

this is useful question

Dr.

Yes you can that.

 the absorption frequency is acutely dependent on the size and shape of particles (given the size distribution is narrow). Hence, it might be possible to evaluate their size using UV- spectroscopy.

 it is possible to count the size spectrometer using ultraviolet rays because   The frequencies  absorbability depends on the shape and size of particles