Dear All,
We used 0.45, 1.2 and 2.5 uM filter papers for vacuum filtration for during the sythesis of graphene oxide with the Hummers method for washing of the material after final treatment with H2SO4. But each time the filter papers get clogged before long and we cannot pass almost any distilled water.
What pore size of paper do you suggest we use?
Figure: Water remaining after 2 hours of vacuum filtration on 2.5 uM filter paper
Kind regards,
Centrifugation process can also be used for washing purposes. Sarp Celebi
Dear Mayank Pathak,
We also do that, but in our FTIR results for GO we saw some signals that could be attributed to Mn impurities, so we thought maybe centrifugation was not as efficient.
If Some Mn impurity is there it means more centrifugation requires. You can try a re-wash by centrifuge at least 8 times in a row.
Mayank Pathak thanks you for the quick replies. Do you have any suggestions about the pH after these runs of centrifugation? We trying to reach 7, but it seems to be impossible.
You'll reach near to 7 pH after 8 times wash. And then if you want to reach exact 7, go for 8 more times. It means, total 16 times centrifugation. This is the drawback of Hummers method that it waste a huge amount of water. If one can find a way to develop GO without wasting too much of water that would save time and water along with the high impact on the researchers in this field.
- Badges
- Science topic
- Similar topics
- Engineering
- Modeling