Hi Hanan,

Before it would be relevant to discuss sample based phenomena, we should first verify that your result has been derived from reliable data, as noisy data will tend to report a value close to zero.

Are you able to share any details of how you performed the measurement and any data from your instrument?

To add to Alex's response, have you measured an appropriate zeta potential standard before and after your measurements? Please show the report(s) and any information from the Expert Advice and Quality report.

Stabilization of disperse systems can be not only due to the addition of ions of electrolytes with a large zeta potential. It can be due to the formation of a two-dimensional film on the surface of particles, which has increased structural and mechanical properties.Gum arabic is a complex and variable mixture of arabinogalactan oligosaccharides, polysaccharides, and glycoproteins. You have given us an example of such a stabilization with a small zeta potential. It is necessary to pay attention to the recommendations of previous experts.

Gum Arabic is a mixture of glycoproteins and monosaccharides. As such, there are no ionogenic functionalities and, hence, no reason to expect significant charge formation.

There are a lot of -OH groups and it is possible that at sufficiently low pH you could get |-OH2+ + -OH(aq) and at sufficiently high pH you could get |-O- + H+(aq). The glycoproteins may also be protonated at the -NH groups, too.

Hi Alexander,

Thanks for your reply.

I analysed different emulsifiers (gum arabic, lecithin, modified starch) in different emulsifier : oil ratio = 1:1 and 1:2 respectively. I got for all very low close to zero zeta potential. Information about the measurement: Temp.: 25 C, Smoluchwski model, dispersant: water. What other information do you need?

Hi All,

Thank you for your replies. Mr. Yuri, I did not got the idea behind your last sentence. This is the report I got. I diluted the sample to 0.1 w/w%, 0.05 w/w% and 0.025 w/w%. I will send later the quality report Mr. Alan.

Hanan, those values for mobility and zeta potential are so small that I suspect you may have a very weak light signal or a lot of bright light coming from somewhere such as a scratch on the cuvette.

Ordinarily, a sample with true zero mobility would probably give you a small range of values (1mV or so) just because of the limitations of the method.

The report will be helpful.

I am sending the quality report of gum arabic two dilutions, one of them was good and the other was poor as a quality.

Thanks for your help.