I am preparing cellulose nanocrystals by acid hydrolysis. After centrifugation step, I put the dispersion in dialysis bag until constant pH. In order to use shorter length of dialysis bag (they are rather expensive), I use high concentrations (more than 5 wt%) and after 9 days I reach to nearly pH 7. But in some papers, it is recommended to use very dilute concentrations of CNC.
Does the concentration only affect the time to reach neutral pH or something else?
enough to occours difusion and contact of all solution to go out of the membrane. Not so low to compartiments achieve fast equal concentration. Not so high to avoid particles agregation up critical concentration too.
Usually, CNC obtained by H2SO4 hydrolysis is more stable and you could use higher concentrations
I experiment good results using 1 mg.mLe-1. I follow the difusion measuring the out water by conductimetry.
Dear Cleverton
Thank you so much for your kind answer
1 mg.mL-1 means 0.1 wt% . I have to prepare quite a large amount of CNC and due to financial limitations it is not possible for me to use that concentration. Is the aggregation a serious problem? won't the aggregations disintegrate during sonication? Do you think that high concentration wouldn't let low molecular weight species and H+ ions diffuse out of the membrane completely in compare with very dilute concentrations if I hold them in the dialysis bag for longer time?
Hi!
During my experiments i have used an -approximate- concentration of 1% on dialisys.
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