Factors that would affect re-crystallization?
*Temperature
*Heating Rate
*Pressure
*Dust or hair that causes nucleation
* Time (slow cooling)
This is what I have, are there anymore?
Thank you
I'm not sure how heating rate would affect re-crystallizaton. It will affect how fast the crystals re-dissolve.
I would add concn as a factor for re-crystallization.
Yes, you have identified several important factors that can affect the process of re-crystallization. However, there are a few more factors that can also have an impact:
1. Solvent choice: The choice of solvent can greatly affect re-crystallization. It should be a good solvent for the compound to be purified, allowing it to dissolve at elevated temperatures but causing it to crystallize out when the temperature is lowered. A poor solvent may not provide efficient purification or may result in multiple impurities being trapped in the crystals.
2. Seed crystals: The presence of seed crystals can influence the re-crystallization process. Adding a small amount of the desired compound as seed crystals can help to induce the growth of larger, purer crystals during re-crystallization.
3. Stirring or agitation: Stirring or agitation during the cooling process can promote uniform crystal formation and prevent localized supersaturation, which can lead to the formation of unwanted impurities or smaller crystals.
4. Impurities: The presence of impurities can affect re-crystallization by either inhibiting or promoting crystal growth. Impurities that have similar solubility characteristics to the desired compound may co-crystallize, resulting in impure crystals. On the other hand, impurities that have different solubility characteristics may be left behind in the mother liquor during the re-crystallization process.
5. pH: For compounds that exhibit pH-dependent solubility, adjusting the pH of the solution can significantly impact re-crystallization. Changing the pH can alter the solubility of the desired compound and other impurities, thereby affecting the yield and purity of the final crystals.
6. Concentration: The concentration of the compound in the solvent can impact the re-crystallization process. A higher concentration may lead to faster and more efficient crystal formation, while a very dilute solution may result in slower or incomplete crystallization.
It's important to note that the specific effect of these factors can vary depending on the compound being re-crystallized, so it is always recommended to optimize the conditions based on the desired outcome.