I am working on fly ash based geopolymers. I prepared a 12M NaOH solution, allow it to cool down for 24hrs and mix it with Na-Silicate. But a few minutes later the NaOH and silicate solution starts to change its colors to cloudy and then forms a hard solid material instead of staying liquid as my previous experiments.
Dear Abel,
what you are describing seems connected to the purity of your system.
Take care about temperature when you work with these materials because solubility can change so maybe something can be not balanced like your previous experiments made at different temperature.
Check on the prof. Davidovits book ,that you can find at www.geopolymer.org in the shop area, how to obtain user friendly liquid reagents at best.
Check also at the quality of the distilled water, if isn’t completely salts free, due filter problems, can affect your work.
Best
Alex Reggiani
Dear Abel,
Check your grade of sodium silicate, in general A-53 grade has been used widely.
Regards
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