| Summary: | 碩士 === 長庚大學 === 化工與材料工程學系 === 102 === A model is developed based on turbidity measurements of the nucleation event to correlate the classical nucleation theory with the induction time and the MSZW data, respectively. The induction time or the MSZW limit is assumed to correspond to a point at which the total projected area density or total number density of accumulated crystals in the detector direction has reached a fixed (but unknown) value. By fitting the experimental induction time data with the developed model, the interfacial energy of L-glutamic acid is recovered for the system by mixing aqueous sodium glutamate solution and sulfuric acid solution. Similarly, by fitting the experimental MSZW data with the developed model, the interfacial energy of L-glutamic acid and glycine is also recovered by the polythermal method for the aqueous L-glutamic acid solution and glycine solution, respectively.
From the calculation based on induction time, the interfacial energy of α-form L-glutamic acid is 8.03~8.23mJ/m^2 , while based on MSZW, it’s 0.60~4.10mJ/m^2 . It may be caused due to the sodium and sulfate ions in the solution which will prevent the binding of glutamate ions and hydrogen ions, thus resulting in large interfacial energy in the induction time experiments. Meanwhile, from the calculation based on MSZW, the interfacial energy of α-form glycine is 0.93~1.50mJ/m^2 . The results are close to the existing references.
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