Questions about crystallization
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I would like to ask all the heroes, what factors are related to the crystallization of substances (other than temperature and concentration)? For example, I have a sugar that has reached a supersaturated state at a certain temperature. How can I prevent it from crystallizing without lowering the temperature and concentration?
Crystallization does not necessarily form immediately. A certain degree of supersaturation is generally required.
Since you said how to prevent crystallization without lowering the temperature and concentration, then you should increase the temperature, otherwise crystals will definitely precipitate when the supersaturation reaches a certain value!
By the way, what I said above is wrong, it means not raising the temperature and lowering the concentration. I heard that there is a stabilizer, but I don’t know if there is such a thing.
Did the poster make a typo? Is it precipitation? Then add crystal seeds! The reason why supersaturation does not precipitate is because the energy during crystallization is a little higher than the energy when it is just saturated. Adding a seed crystal means that the high energy point has been crossed. For details, please read books on inorganic chemistry and stir like crazy. It will also precipitate. If it does not precipitate, it is to keep the system stable. Do not add seeds and do not over-stir. Also, what kind of sugar is the poster, adding a stabilizer is also a good way.
Our company now has xylitol liquid alcohol, which contains xylitol, sorbitol, dulbitol, arabinol, etc. The customer's requirement is that the alcohol concentration is 60-70%, but dulbitol is easy to crystallize. At this concentration, dulbitol will easily crystallize out, causing the product to become turbid. Although its properties will not change, the customer is not very satisfied with the appearance, so I would like to ask now, what method can be used to solve this crystallization problem? If you have any tips, please give me some tips!
Is it possible to consider the melt crystallization method, that is, to allow the easy-to-crystallize dulbitol to crystallize directly in the crystallizer? For example, use a falling film melting crystallizer to control the appropriate temperature so that dulbitol can crystallize on the wall. The mother liquor obtained is what you want. The dulbitol crystallized on the wall is recovered by heating and dissolving. Or change the content of other sugars or alcohols in the system to further increase the viscosity of the system and increase the surface tension of the system to inhibit the crystallization of dulcitol. This post was last edited by trampwin on 2009-3-13 17:04 ]
As long as a seed crystal is not formed, it will not crystallize:victory:
Try to leave it as still as possible, it usually won't crystallize.
It is estimated to be difficult. The stirring and other measures used in the crystallization process only affect the size of the crystal and the formation of crystal nuclei, which should not be achieved for the purpose of the original poster. It is recommended to discuss and communicate with the customer, sell pure products, and then let the customer mix the proportion to the required concentration.
Yes you can add some seed crystals to it! According to an example, you know what a seed is. When you grow a crystal (imagine it), you must first put a small crystal in it, so that the material particles will continue to condense on the surface of the small crystal to form a solid precipitate. Such small crystals are seed crystals. The core of the seed crystal is the crystal nucleus, which here refers to something similar to the condensation nucleus. In the titanium dioxide industry that I know, there are a lot of applications for seed crystals! I can upload some information if needed.:lol
Brother, his goal is not to crystallize, but to reduce crystallization. . . .
Changing the pressure should also be useful for writing. As long as no crystal nuclei are formed, it will remain in a supersaturated state. After the crystal nuclei are formed, they will grow and crystallize.