Hi,I am trying to make graphene based hydrogel via the hydrothermal route.I tried heating a 30mL, 1mg/ml graphene oxide(GO) solution in 50 ml autoclave for 12hrs.At the end i found only carbon soot left at the bottom.Also,I tried heating 30 ml, 2mg/ml GO solution in 50ml autoclave for 3 hrs,but got a paste at the bottom with no mechanical strength.I do not understand what I am doing wrong.Please help.
Dear Soudip Basu,
I can only suggest that you should try lower the concentration of GO maybe to 0.5 mg/mL and perform the synthesis for 24 hours with the same amount of mixuture. I've tried to receive a hydrogel via hydrothermal method, however it is very difficult to even repeat the process given in literature.
I hope you will succed in your next attempts.
Dear Soudip,
There are many questions for you to think about first.
Are you trying to follow a particular route been reported by someone else ? and if yes then please share the article here for anyone to see the missing link!
Other question is to what temperature did you heat your solutions at?
thirdly from our experience, generally the hydrogels are not easy to prepare and you have to follow a particular recipe very carefully as any difference in your and reported procedure, such as concentrations, reagent to solvent ratios, temp, time and volume, can cause issues.
All the best.
Rehan
Hello Soudip,
let me know weather the autoclave you are using is teflon lined or not?
What type of polymer or crosslinker is involved in the hydrogel you are trying to develop?
Dear Soudip,
you are not doing anything wrong. You should maintain the pH of GO suspension kept in autoclave in basic range, preferably around 10 to 11 using ammonia. Hope fully you should get gel. Also make sure, the temperature in not above 180 C and not below 140 C.
(1)It is a TEFLON lined container.
(2)The temperature is 180C.
(3)I have attached the article
The only difference is that I am using a 50mL autoclave while they used 16mL autoclave.
Dear Soudip,
Well that's the missing link probably, if you are using a different sized autoclave then you need to make sure that you have at least same autoclave fill % with published work, as if used different fill % then that would effect the pressure of the system and hence could disturb the overall reaction mechanism.
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