Hi, I was using the Malvern Zetasizer to measure the zeta potential of GNPs in simulated cement pore solution. when I measure the zeta potential of GNPs in simulate cement pore solution, the software shows the message "Problem with cell drive circuit". In the SOPs, the materials is "Polystyrene latex", the dispersant is added manually with a dielectric constant of 5.2 (I checked in the literature, the dielectric constant is around 5.2 of simulated pore solution). But the zeta potential cannot be measured with this SOPs, and shows the message "Problem with cell drive circuit". The GNPs is conductive and the concentration is 0.02 g/L. Do you know how to measure the zeta potential of GNPs in simulated cement pore solution?
The simulated cement pore solution is saturated Ca(OH)2 with 8g/L NaOH, 22.4g/L KOH and 27.6 g/L CaSO4. PH is around 13.3
Hello Zhangfan Jiang ,
it sounds like this might be a challenging sample. You indicate a low dielectric constant and high salt and very high pH.
Can you check the log file and see which previous information may be mentioned in there, it might help to resolve. The log file is at This PC > Documents > Malvern Instruments > Zetasizer > Logs . Find the file from the date and open it (it is a text file, open with notepad) and scroll to the end to locate the event when it happened. Any relevant messages prior to the "Problem with cell drive circuit"?
Next I would check that the instrument performs OK with a normal sample, like polystyrene latex beads. I would then check if size measurements by DLS are possible. Does the sample look clear or opaque? What is the viscosity? Which cuvette type have you tried for this?
Hi Ulf Nobbmann , Thanks for your answer!
I checked the log file, and the messages is shown below.
The instrument performs OK with the normal sample. And the size measurement by DLS is possible for the simulated cement pore solution sample..
Because the solution has graphene inside, so the sample looks grey, but it is not opaque. I am not sure about the viscosity, but it looks similar as water solutions. I am using the disposable cuvette.
I tried the Saturated Ca(OH)2 solution today, the similar setup, the zeta potential can be measured with the saturated Ca(OH)2 solution. But with the simulated cement pore solution, the zeta potential can not be measured.
I did some more test today. Since the solution is complex. I did the zeta potential on KOH, NaOH, CaSO4, and saturated Ca(OH)2 separately. CaSO4 and saturated Ca(OH)2 works OK. But the NaOH and KOH solution still shows the same message
This is probably due to the very high pH. Are there gas bubbles forming on the electrodes?
You could possibly try a later software version, free to download. You could try on a different computer if you are worried about changing your system: https://www.materials-talks.com/blog/2015/03/09/how-to-get-the-latest-software-for-the-zetasizer-nano/
In later software versions, the log file should indicate which cuvette type was used. But I am not sure it would make a difference in this measurement.
Ulf Nobbmann , There is no gas forming on the electrodes. I am using the zeta dip cell with the disposable cuvette. The Malvern Technician says this dip cell is OK with the high pH.
I also tried the later software version. The log file shows the same error. Is the conductivity too low for the measurement?
Thanks,
Zhangfan
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