Zeta sizer nano needs a transparent sample but mixing al2o3 nanoparticles make solution white. Is there any other method to check zeta potential or in which way we can use zeta sizer nano ?
@Alan F Rawle: Just a coupe of minor corrections to your text - I trust you'll not mind.
A note on your phrase.
“Zeta potential is not surface potential (although they're related). It's the charge at the slipping plane which is some distance away from the particle itself.”
The zeta potential is electrical potential, the energy characteristic of the electrostatic field. Measured in Volts.
The charge (amount of electricity) determines the ability of bodies to be the source of electromagnetic fields and to participate in electromagnetic interaction. Measured in Coulombs.
Zetasizer needs a transparent sample? Do not think so. Read the zetasizer manual please.
Zeta potential is a holistic property of particle and the medium it resides in. So you need to measure the pH for starters is order to quote a zeta potential value. You need conductivity to enable mobility in a suspension and thus you cannot measure zeta potential in DI water. Normally a background such as 0.001M NaCl can be selected to give sufficient conductivity. As stated above, you do not need a transparent solution and I don't know where this idea has come from. If your suspension is too concentrated for light to get in and out then you may need to dilute in the appropriate mother liquor. If the suspension is too large, allow to settle and take some of the supernatant for the zeta and pH measurement. As also stated above, read the manual.
Zeta sizer measures the surface potentials of any nano material at a liquid state. Make sure that the synthesized nano particles bear adequate surface charge (positive or negative) for its colloidal stability. A range less than -20 mV or more than + 20mV is generally considered good for the colloidal stability of any nano particle. You can acquire surface functionalization methods to impart surface charge to your particles.
@ Abhishek Bhattacharya Just a coupe of minor corrections to your text - I trust you'll not mind. Zeta potential is not surface potential (although they're related). It's the charge at the slipping plane which is some distance away from the particle itself. A charged particle carries around with it a swathe of counter ions and the charge on this combined particle + counter ion surround is how a particle acts in suspension with respect to other particles. For nanoparticles 20 mV is almost certainly inadequate for stabilization as is the oft-quoted 30 mV. We must also remember that this applies to charge (I don't like the term 'electrostatic') stabilization and with steric stabilization (a surround of polymer akin to cotton wool around the particle), then a measured charge of 0 mV may still result in a stable system as the slipping plane is located in the polymer layer. The oft-quoted 30 mV results from Riddick's table (I'll attach this) where 30 mV is stated to be 'moderate stability'. Riddick was referring to blood cells of several microns in size. For smaller particles then more charge is needed to overcome the van der Waals attractive forces. For example I give an example of ~ 300 nm (not nano!) TiO2 where approximately - 70 mV confers stability - it's unstable at - 52 mV. See slides 49 onwards in:
Nov 11th, 2008. Dispersion and nanotechnology http://tinyurl.com/hpywsge
@Alan F Rawle: Thank you so much for your concern and corrections. The electrophoretic mobility shift assay is another excellent tool to measure and quantify the charges of any nanoparticle. Certainly the zeta potential will differ depending on the material in question.
@Alan F Rawle: Just a coupe of minor corrections to your text - I trust you'll not mind.
A note on your phrase.
“Zeta potential is not surface potential (although they're related). It's the charge at the slipping plane which is some distance away from the particle itself.”
The zeta potential is electrical potential, the energy characteristic of the electrostatic field. Measured in Volts.
The charge (amount of electricity) determines the ability of bodies to be the source of electromagnetic fields and to participate in electromagnetic interaction. Measured in Coulombs.
@Alan what if the -ve value in Table 1 become +ve. I think it's all depend on the magnitude of Zp.
@Alan what if the negative value in Table 1 become positive. I think it all depends on the magnitude of Zp.
Dear Alan
What if the negative value in Table 1 become positive. I think it all depends on the magnitude of Zp.
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