Hello! I have a co-amorphous system with API-Tryptophan and API-Phenyalalnine obtained milled. Amino acids could not be transformed into an amorphous form via ball milling, so I cannot get the glass transition temperature of pure amorphous amino acids. So the questions are:
1.Where then to take the glass transition temperature for amino acids?
2. To determine the constant, it is necessary to know the density of amorphous substances. In the literature, I found that the density of a crystalline substance is used, as far as this is correct?
I would be very grateful for an explanation of this issue. Thanks in advance
If someone is interested in the answer to the question I asked earlier. In the G-T equation, the densities of crystalline substances can be used as the densities of amorphs. (This is true for small molecules such as our amino acids). Ref [1,2]
Converting crystalline amino acids to amorphous ones by the grinding method is a non-trivial task; therefore, to determine Tg, one can use the data obtained from amorphous samples obtained by lyophilization (freeze-drying) Ref [3,4]
Hi Nikita,
Thank you for the update.
I wonder when can we use the Fox equation since it requires no density:
https://link.springer.com/article/10.1208/s12249-019-1562-1?utm_source=getftr&utm_medium=getftr&utm_campaign=getftr_pilot
Kind regards
Hi Nasser Alhajj. This is an interesting decision, I think we should all pay attention to it)
- Badges
- Science topic
- Similar topics
- Chemistry, Organic
- Organic