Analytical and Physical Chemistry of Materials Sergey Vyazovkin received his BS (1982) and PhD (1989) from the Byelorussian State University. He then joined the Institute for Physical Chemistry (Minsk) where he worked until 1993. Since 1993 he had held visiting positions at the Technical University of Vienna (1993-1995) and University of Toledo (1995). Before joining the University of Alabama at Birmingham, he worked in the University of Utah (1995-2001) as a research faculty and the deputy director of the Center for Thermal Analysis. E-mail: Vyazovkin@uab.eduTel.: (205) 975-9410
Activities and honors.
Editor: Thermochimica ActaEditorial Board: Journal of Thermal Analysis and Calorimetry (2003 - 2006), Macromolecular Chemistry and Physics, Macromolecular Rapid Communications2003, 2007 Invited Professorship, Université de Nice-Sophia Antipolis2004 Mettler-Toledo Award for “Outstanding Contributions in the Field of Thermal Analysis”2006 James J. Christensen Award for “Outstanding Contributions to the Innovative Development and Use of Calorimetric Equipment”2006 Elected Fellow of the North American Thermal Analysis Society.
Research interests.
Our research interests are concerned with thermophysical properties and reactions of polymeric, pharmaceutical and energetic materials. We study these materials by using a variety of analytical techniques including Infrared (IR) Spectroscopy, Mass Spectrometry (MS), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Thermomechanical Analysis (TMA), Dynamic Mechanical Analysis (DMA), Polarized Light Microscopy (PLM), etc. Kinetic analysis of thermal data plays the key role in our work. We develop and apply our original kinetic methodology “Isoconversional Kinetic Analysis” also known as “Model-free Kinetics”.
Polymers.
We focus on the processes of degradation, relaxation, crystallization, and polymerization. Our relaxation and degradation research is focused on polymer nanocomposites. We use the TGA, MS, IR, DSC, and DMA to understand the effect of polymer chain nanoconfinement on the thermal behavior of polymers. Nonisothermal crystallization of polymer melts and glasses is another area of our work. We develop new kinetic methods for evaluation and interpretation of the temperature dependence of this process. DSC and PLM are the major tools in the crystallization studies. Our polymerization studies are concerned with the reaction of epoxy with various organic and metallorganic curing agents as a route to nonlinear optical and liquid crystalline materials. The properties of epoxy materials are largely determined by the kinetics of the curing process that we study by means of the DSC and DMA techniques.
Pharmaceuticals.
Amorphous pharmaceuticals are inherently unstable and tend to relax toward the stable crystalline state that ultimately results in the formation of crystalline drugs, which have significantly lower bioavailability. In order to evaluate stability of the amorphous drugs we probe their relaxation kinetics at temperatures significantly below the glass transition temperature. DSC is employed to detect the process of relaxation and crystallization occurring in aged amorphous samples.
Energetics.
We use TGA and DSC to study the thermal decomposition kinetics of explosives and propellants. Obtaining reliable kinetic characteristics of decomposition is important for estimating thermal stability of energetic materials as well as for simulating the decomposition rates at the high temperatures associated with the combustion conditions. By combining DMA and MS, we have developed a novel analytical technique for studying mechanochemical effects in degradation of energetic materials such as nitrocellulose.
Equipment:
Mettler-Toledo: TGA 851e, DSC 822e, DSC 823e (TOPEM® – multi-frequency temperature modulated DSC), TMA 840, High Pressure DSC 27HP, DSC 30, FP84HT hot stageOlympus Polarized Light MicroscopeTritec 2000 DMAPfeiffer Thermostar Quadrupole MSNicolet Nexus 470 FTIR Spectrometer.
Funding:
Department of Defense, Army Research Office, Boehringer-Ingelheim Cares Foundation, NSF Center for Pharmaceutical Processing Research, ACS Petroleum Research Fund.
Group members since 2001:
Undergraduate students: Jay Stone, Mike Susner, Stephanie Martindale, Kehley Harris, Amy Jablonski, Ashley Baker
Graduate students: Yanxi Zhang, Justin Lang, Kai Chen, Jeff Atkinson
Postdoctoral students: Ion Dranca, Kai Chen
Selected Publications
S. Vyazovkin, Isoconversional Kinetics, p. 503-538, Ch. 13 in: “The Handbook of Thermal Analysis & Calorimetry, Vol.5: Recent Advances, Techniques and Applications”, Eds. M. E. Brown, P. K. Gallagher, Elsevier, 2008
128. S. Vyazovkin, Thermal Analysis, Anal. Chem. 2008, v. 80, N12, 4301 (invited fundamental review).
126. A. J. Lang, S. Vyazovkin, Phase and Thermal Stabilization of Ammonium Nitrate in the form of PVP-AN Glass, Mater. Lett., 2008, v. 62, 1757.
125. K. Chen, K. Harris, S. Vyazovkin, Tacticity as a factor contributing to the thermal stability of polystyrene, Macromol. Chem. Phys., 2007, v. 208, 2525 (featured on journal cover).
124. K. Chen, C. A. Wilkie, S. Vyazovkin, Nano-confinement Revealed in Degradation and Relaxation Studies of Two Structurally Different Polystyrene-Clay Systems, J. Phys. Chem. B, 2007, v. 111, 12685.
123. S. Vyazovkin, K. Chen, Increase in Effective Activation Energy During Physical Aging of a Glass, Chem. Phys. Lett., 2007, v. 448, 203.
122. S. Vyazovkin, L. Vincent, N. Sbirrazzuoli, Thermal Denaturation of Collagen Analyzed by Isoconversional Method, Macromol. Biosci., 2007, v. 7, 1181 (featured on journal cover).
121. Y. Zhang, S. Vyazovkin, Effect of Substituents in Aromatic Amines on the Activation Energy of Epoxy-Amine Copolymerization, J. Phys. Chem. B, 2007, v. 111, 7098.
120. S. Vyazovkin, I. Dranca, Effect of Physical Aging on Nucleation of Amorphous Indomethacin, J. Phys. Chem. B, 2007, v. 111, 7283.
118. S. Vyazovkin, N. Sbirrazzuoli, Isoconversional Kinetic Analysis of Thermally Stimulated Processes in Polymers, Macromol. Rapid Commun., 2006, v. 27, N18, 1515-1532 (invited feature article, featured on journal cover)
108. S. Vyazovkin, I. Dranca, Isoconversional Analysis of Combined Melt and Glass Crystallization Data, Macromol. Chem. Phys., 2006, v. 207, 20.
107. S. Vyazovkin, I. Dranca, Physical Stability and Relaxation of Amorphous Indomethacin, J. Phys. Chem. B 2005, v. 109, 18637.
104. Y. Zhang, S. Vyazovkin, Curing of diglycidyl ether of bisphenol with nitro derivatives of amine compounds: 2. 3-nitro-1,2-phenylenediamine, Macromol. Chem. Phys., 2005, v. 206, N10, 1084-1089. (featured on journal cover).
103. K. Chen, M. A. Susner, S. Vyazovkin, Effect of the Brush Structure on the Degradation Mechanism of Polystyrene-clay Nanocomposite, Macromol. Rapid Commun., 2005, v.26, 690.
100. S. Vyazovkin, I. Dranca, A. J. Lang, Detecting mechanochemical degradation of nitrocellulose by combining dynamic mechanical analysis with mass spectrometry, Macromol. Rapid Commun., 2005, v.26, N1, 29-33 (featured on journal cover).
98. S. Vyazovkin, I. Dranca, A DSC Study of a- and b-relaxations in a PS-clay System, J. Phys. Chem. B, 2004, v. 108, 11981.
95. S. Vyazovkin, N. Sbirrazzuoli, Isoconversional Approach to Evaluating the Hoffman-Lauritzen Parameters (U* and Kg) from the Overall Rates of Nonisothermal Crystallization, Macromol. Rapid Commun., 2004, v. 25, 733
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