“Application of temperature cycling for crystal quality control during crystallization”
Abstract
Characteristics of crystal quality, including crystal size distribution, size, morphology, polymorphism and chirality, have been established as important indicators of crystalline materials. There have been many attempts at controlling crystal quality during crystallization. Herein, this study summarizes crystal quality control by using temperature cycling during solution state crystallization. During crystallization, the temperature cycling is implemented through successive heating–cooling cycles for dissolution and recrystallization in crystal suspension. Therefore, the fines crystals or one species are expected to dissolve out completely during the heating period, and the remaining crystals or dominant species continuously grow or nucleate during the cooling period. When such temperature cycling is facilitated during crystallization, the characteristics of crystal quality, including crystal size distribution, size, morphology, polymorphism and chirality, are well managed. Furthermore, based on the basic principle of temperature cycling, the key parameters for controlling each characteristic of crystal quality are clearly elucidated during the process. Thus, this review provides qualitative insight into the general operation strategies and the principle of temperature cycling for crystal quality control during crystallization.
Hav u ever experimented with this GAS antisolvent technique? co2scienceCrystal.pdf (1.3 MB)
I primarily make co2 extracts so im always on the lookout for new applications for co2. and there r a tone of them lol
i was just researching how co2 can be used to break the ethanol/water azeotrope without much energy requirments
So, is this basically saying that if I will pull it off the 85f, let it cool then repeat over and over and stages the crystals will get larger from the cooling stage… If so I’ll definitely try this does the colder the better help should I put it in the freezer I may have this completely wrong how long should the phases be if I do have this right, and how big a temp swing
any recommendations on pressure vessels? BVV sells one for like $800 which seems a big outrageous for what it is. It seems you could build one yourself for less than $100 unless I’m missing something.
I am curious for anyone who has successfully tried this, would you do this throughout the whole growth cycle, most of the cycle, or temp cycle just in the beginning? It’d seem that letting them grow undisturbed for the last week with out any redissolving might be beneficial, unless the larger crystals stay mostly undisturbed during the dissolution park of the temp cycle. Also what are your preferred temp cycles? 0-20 C over 1-2 hours?
I’m hoping I can create a schedule that will aid in crystal formation with my ETS miner. I am going to start with 35c for 12 hours and then to -40c for 12 hours for one week.
Can anybody recommend a better starting point or share what they’ve been successful with?
Only temp control/monitoring is on the circulated chiller. Internal temps will obviously be different but a thermowell from Swagelok could probably be adapted into one of the ports on top if tighter controls would be needed.
