Can I Successfully Freeze Dry Phosphoric Acid-Soaked Carbon at Home?

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Discussion Overview

The discussion revolves around the feasibility of freeze drying carbonaceous material soaked in phosphoric acid at home, specifically focusing on the methods and tools available for this process. Participants explore the technical aspects of freeze drying and subsequent activation of the carbon under inert conditions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes their setup involving a vacuum chamber and a household freezer to freeze dry the phosphoric acid-soaked carbon.
  • Another participant expresses skepticism about the effectiveness of the method, suggesting that continuous suction is necessary for successful freeze drying, which their setup lacks.
  • A participant clarifies their goal of obtaining a carbon-phosphoric acid powder that can be activated at high temperatures to enhance surface groups and porosity.
  • A later update from the original poster indicates that, contrary to initial doubts, the freeze drying process succeeded, resulting in a powder after four days.

Areas of Agreement / Disagreement

Participants express differing views on the effectiveness of the freeze drying method, with some skepticism about the setup's ability to maintain continuous suction. However, there is no consensus on the overall success of the method until the final update is presented.

Contextual Notes

The discussion highlights limitations related to the vacuum chamber's design and the assumptions about the freeze drying process. The effectiveness of the method remains contingent on specific conditions that may not be met in a home setup.

Who May Find This Useful

This discussion may be of interest to individuals exploring home chemistry experiments, particularly those focused on carbon activation processes and freeze drying techniques.

copper-head
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Hello all.
I have carbonaceous material soaking in Phosphoric acid. I'd like to anneal it under an inert environment to activate the carbon. One method used in literature involved freeze drying the mixture and annealing it as is, as opposed to filtering or centrifuging the mixture. However, I am limited to a regular household freezer and a vacuum chamber. Does anyone have recommendations on how to achieve this with specialty tools?
Cheers
 
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An update.
I built a small size vacuum chamber and placed the Phosphoric acid soaked material in a petri dish inside the chamber. After pumping the air out, I place the chamber in the freezer. After 24 hours there was build up of sublimated vapor in the chamber, so I pumped that out one more time and replaced the chamber in the freezer.
This is likely to fail. Here my opinion on why drying this into a powder would not work using this method: Freeze drying requires a continuous suction to extract the phosphoric acid vapors out of the chamber. This is would likely not happen using my contraption as my suction is not continuous and hence what I am doing is freezing a substance under vacuum. I'll keep at it for a few more days and update on the progress.
 
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What are you actually trying to do ?
 
Well, the idea is to dry this carbon which is soaking in Phosphoric acid to obtain carbon-phosphoric acid powder to be later activated at high temperature under inert environment. This creates surface groups on the carbon as well as increases porosity.
 
copper-head said:
Well, the idea is to dry this carbon which is soaking in Phosphoric acid to obtain carbon-phosphoric acid powder to be later activated at high temperature under inert environment. This creates surface groups on the carbon as well as increases porosity.
AN Update:
Contrary to my expectations, it worked! the gooey phosphoric acid soaked material turned into powder 4 days later. If anyone is interested in the vacuum chamber schematics, let me know.
 
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