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Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation
Published on: May 2, 2016
Effects of cooling rate on structural relaxation in amorphous drugs: elastically collective nonlinear langevin
Anh D Phan1,2,3, Katsunori Wakabayashi3, Marian Paluch4
1Faculty of Materials Science and Engineering, Phenikaa Institute for Advanced Study, Phenikaa University Hanoi 12116 Vietnam anh.phanduc@phenikaa-uni.edu.vn.
Abstract:
Theoretical approaches are formulated to investigate the molecular mobility under various cooling rates of amorphous drugs. We describe the structural relaxation of a tagged molecule as a coupled process of cage-scale dynamics and collective molecular rearrangement beyond the first coordination shell. The coupling between local and non-local dynamics behaves distinctly in different substances. Theoretical calculations for the structural relaxation time, glass transition temperature, and dynamic fragility are carried out over twenty-two amorphous drugs and polymers. Numerical results have a quantitatively good accordance with experimental data and the extracted physical quantities using the Vogel-Fulcher-Tammann fit function and machine learning. The machine learning method reveals the linear relation between the glass transition temperature and the melting point, which is a key factor for pharmaceutical solubility. Our predictive approaches are reliable tools for developing drug formulations.
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