Hello. I have been doing my thesis on bioglass (SiO-Na2O-CaO-P2O5) and I did DTA and the obtained curve looks like this. But I don't know how to find Tg and Tc and melting point from this curve. Because it's not straight. Can you please suggest publications or books that can help me with identifying this curve, please?
DTA not well suited for determining the Tg point. For this purpose, differential scanning calorimetry (DSC) method or dilatometry are used: https://en.wikipedia.org/wiki/Glass_transition
But even from your DTA curves, Tg is around 500°C and TL is around 800°C.
It seems to me that from this curve it is very difficult to determine a T glass or other. Have you calibrated the instrument?
1. It is not necessary to go to such a high temperature, there is no important information between 1000 and 1400oC; stop the heating at 1000oC.
2. Also, there are no thermal transitions lower than 400oC; then do not include these values in your graph.
3. Do the graph again, it will be more clear for the analysis.
4. Include a text indicating the heating and cooling cycles.
5. For the peaks (thermal transitions) use the criteria of the intercept of the baseline with the slope of the peak (the right-side for the cooling, the left side for the heating).
Good look
Good day,
did you use a simultaneous instrument perhaps? DTA/TGA. TGA information will also be insightfull with regards to mass loss or mass gain.
I agree with Vadim Verlotski sir. Differential scanning calorimetry (DSC) will be more accurate in glass thermal analysis. Still, i would suggest you not to overlook multiple glass transition temperature, it could be there in sol-gel derived 45S5 glass composition.
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