1
|
Lapuk SE, Mukhametzyanov TA, Schick C, Gerasimov AV. Stability of Rapidly Crystallizing Sulfonamides Glasses by Fast Scanning Calorimetry: Crystallization Kinetics and Glass-Forming Ability. J Pharm Sci 2024; 113:1257-1264. [PMID: 38070775 DOI: 10.1016/j.xphs.2023.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 04/19/2024]
Abstract
Production and evaluation of the kinetic stability of the amorphous forms of active pharmaceutical ingredients are among the current challenges of modern pharmaceutical science. In the present work, amorphous forms of several sulfonamides were produced for the first time using Fast Scanning calorimetry. The parameters, characterizing the glass-forming ability of the compounds, i.e. the critical cooling rate of the melt and the kinetic fragility, were determined. The cold crystallization kinetics was studied using both isothermal and non-isothermal approaches. The results of the present study will contribute to the development of approaches for producing amorphous forms of rapidly crystallizing active pharmaceutical ingredients.
Collapse
Affiliation(s)
- S E Lapuk
- Department of Physical Chemistry, A.M. Butlerov Institute of Chemistry, Kazan Federal University, 420008, Kremlevskaya, 18, Kazan, Russia
| | - T A Mukhametzyanov
- Department of Physical Chemistry, A.M. Butlerov Institute of Chemistry, Kazan Federal University, 420008, Kremlevskaya, 18, Kazan, Russia
| | - C Schick
- Universitat Rostock, Institute of Physics, Albert-Einstein_str. 23-24, Rostock, DE 18051, Germany
| | - A V Gerasimov
- Department of Physical Chemistry, A.M. Butlerov Institute of Chemistry, Kazan Federal University, 420008, Kremlevskaya, 18, Kazan, Russia.
| |
Collapse
|
2
|
Walther F, Schick C, Schwappach D, Kornilov E, Orbach-Zinger S, Katz D, Heesen M. The Impact of a 22-Month Multistep Implementation Program on Speaking-Up Behavior in an Academic Anesthesia Department. J Patient Saf 2022; 18:e1036-e1040. [PMID: 35532993 PMCID: PMC9524591 DOI: 10.1097/pts.0000000000001017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Speaking-up is a method of assertive communication that increases patient safety but often encounters barriers. Numerous studies describe programs introducing speaking-up with varying success; the common denominator seems to be the need for a multimodal and sustained approach to achieve the required change in behavior and culture for safer health care. METHODS Before implementing a 22-month multistep program for establishing and strengthening speaking-up at our institution, we assessed perceived safety culture using the "Safety Attitudes Questionnaire." After program completion, participants completed parts of the same Safety Attitudes Questionnaire relevant to speaking-up, and preresult and postresult were compared. In addition, levels of speaking-up and assertive communication were compared with a Swiss benchmark using results from the "Speaking-up About Patient Safety Questionnaire." RESULTS Safety Attitudes Questionnaire scores were significantly higher after program completion in 2 of 3 answered questions (median [first quartile, third quartile), 5.0 [4.0, 5.0] versus 4.0 [4.0, 5.0], P = 0.0002, and 5.0 [4.0, 5.0] versus 4.0 [4.0, 4.0] P = 0.002; n = 34). Our composite score on the Speaking-up About Patient Safety Questionnaire was significantly higher (mean ± SD, 5.9 ± 0.7 versus 5.2 ± 1.0; P < 0.001) than the benchmark (n = 65). CONCLUSIONS A long-term multimodal program for speaking-up was successfully implemented. Attitude and climate toward safety generally improved, and postprogram perceived levels of assertive communication and speaking-up were higher than the benchmark. These results support current opinion that multimodal programs and continued effort are required, but that speaking-up can indeed be strengthened.
Collapse
Affiliation(s)
- Fabio Walther
- From the Department of Anaesthesiology, Kantonsspital Baden, Baden
| | - Carl Schick
- From the Department of Anaesthesiology, Kantonsspital Baden, Baden
| | - David Schwappach
- Swiss Patient Safety Foundation, Zürich
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Evgeniya Kornilov
- Department of Anaesthesia, Beilinson Hospital, Tel Aviv University, Tel Aviv, Israel
| | - Sharon Orbach-Zinger
- Department of Anaesthesia, Beilinson Hospital, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Katz
- Department of Anaesthesiology, Perioperative and Pain Medicine, Mount Sinai, New York
| | - Michael Heesen
- From the Department of Anaesthesiology, Kantonsspital Baden, Baden
| |
Collapse
|
3
|
Lapuk SE, Mukhametzyanov TA, Schick C, Gerasimov AV. Crystallization kinetics and glass-forming ability of rapidly crystallizing drugs studied by Fast Scanning Calorimetry. Int J Pharm 2021; 599:120427. [PMID: 33662469 DOI: 10.1016/j.ijpharm.2021.120427] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/09/2021] [Accepted: 02/20/2021] [Indexed: 11/16/2022]
Abstract
The use of the amorphous forms of drugs is a modern approach for the enhancement of bioavailability. At the same time, the high cooling rate needed to obtain the metastable amorphous state often prevents its investigation using conventional laboratory methods such as differential scanning calorimetry, X-ray powder diffractometry. One of the ways to overcome this problem may be the application of Fast Scanning Calorimetry. This method allows direct determination of the critical cooling rate of the melt and kinetic parameters of the crystallization for bad glass formers. In the present work, the amorphous states of dopamine hydrochloride and atenolol were created using Fast Scanning Calorimetry for the first time. Critical cooling rates and glass transition temperatures of these drugs were determined. Based on the values of the kinetic fragility parameter, dopamine hydrochloride glass can be considered strong, while atenolol glass is moderately strong. Both model-based and model-free approaches were employed to determine the kinetic parameters of cold crystallization of dopamine and atenolol. The results were compared with the data from isothermal crystallization experiments. The Nakamura crystallization model provides the best description of the crystallization process and can be used to predict the long term stability of the amorphous forms of the drugs. The presented approaches may find applications in predicting the storage time and choosing the optimal storage conditions of the amorphous drugs prone to crystallization.
Collapse
Affiliation(s)
- S E Lapuk
- Department of Physical Chemistry, A.M. Butlerov Institute of Chemistry, Kazan Federal University, 420008, Kremlevskaya, 18, Kazan, Russia
| | - T A Mukhametzyanov
- Department of Physical Chemistry, A.M. Butlerov Institute of Chemistry, Kazan Federal University, 420008, Kremlevskaya, 18, Kazan, Russia
| | - C Schick
- Department of Physical Chemistry, A.M. Butlerov Institute of Chemistry, Kazan Federal University, 420008, Kremlevskaya, 18, Kazan, Russia
| | - A V Gerasimov
- Department of Physical Chemistry, A.M. Butlerov Institute of Chemistry, Kazan Federal University, 420008, Kremlevskaya, 18, Kazan, Russia.
| |
Collapse
|
4
|
Lapuk S, Mukhametzyanov T, Schick C, Gerasimov A. Kinetic stability of amorphous dipyridamole: A fast scanning calorimetry investigation. Int J Pharm 2020; 574:118890. [DOI: 10.1016/j.ijpharm.2019.118890] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 01/10/2023]
|
5
|
Abdelaziz A, Zaitsau DH, Buzyurov AV, Verevkin SP, Schick C. Sublimation thermodynamics of nucleobases derived from fast scanning calorimetry. Phys Chem Chem Phys 2020; 22:838-853. [DOI: 10.1039/c9cp04761a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Fast scanning calorimetry was utilized to measure the sublimation thermodynamics of nucleobases. The results were rationalized at the molecular level.
Collapse
Affiliation(s)
- A. Abdelaziz
- University of Rostock
- Institute of Physics
- 18059 Rostock
- Germany
- University of Rostock
| | - D. H. Zaitsau
- University of Rostock
- Faculty of Interdisciplinary Research
- Competence Centre CALOR
- 18059 Rostock
- Germany
| | | | - S. P. Verevkin
- University of Rostock
- Faculty of Interdisciplinary Research
- Competence Centre CALOR
- 18059 Rostock
- Germany
| | - C. Schick
- University of Rostock
- Institute of Physics
- 18059 Rostock
- Germany
- University of Rostock
| |
Collapse
|
6
|
Abdelaziz A, Zaitsau DH, Kuratieva NV, Verevkin SP, Schick C. Melting of nucleobases. Getting the cutting edge of "Walden's Rule". Phys Chem Chem Phys 2019; 21:12787-12797. [PMID: 30888011 DOI: 10.1039/c9cp00716d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Walden's Rule is an empirical observation of an invariant fusion entropy during fusion of non-associated organic compounds. For the five nucleobases, adenine, thymine, cytosine, guanine, and uracil, surprisingly high fusion temperatures and enthalpies have been measured using a specially developed fast scanning calorimetry method that prevents decomposition. Even when nucleobases admittedly possess very high fusion temperatures, e.g. the value of 862 K measured for guanine really exceeds all expectations of the feasible dimension of the fusion temperature for such a relatively small and simple organic molecule. Hirshfeld surface analysis has been applied in order to find out an explanation for such extremely unusual thermal behavior of nucleobases. We rationalized the observed trends in terms of fusion entropy (Walden's constant = 56.5 J K-1 mol-1) as the entropic penalty of fusion not only for "non-associated", as proposed by Walden in 1908, but also for "ideal associated" systems like nucleobases.
Collapse
Affiliation(s)
- A Abdelaziz
- University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany. and University of Rostock, Faculty of Interdisciplinary Research, Competence Centre CALOR, Albert-Einstein-Str. 25, 18051 Rostock, Germany.
| | - D H Zaitsau
- University of Rostock, Institute of Chemistry, Dr-Lorenz-Weg 2, 18059 Rostock, Germany
| | - N V Kuratieva
- Nikolaev Institute of Inorganic Chemistry of Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - S P Verevkin
- University of Rostock, Faculty of Interdisciplinary Research, Competence Centre CALOR, Albert-Einstein-Str. 25, 18051 Rostock, Germany. and University of Rostock, Institute of Chemistry, Dr-Lorenz-Weg 2, 18059 Rostock, Germany and Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russian Federation
| | - C Schick
- University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany. and University of Rostock, Faculty of Interdisciplinary Research, Competence Centre CALOR, Albert-Einstein-Str. 25, 18051 Rostock, Germany. and Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russian Federation
| |
Collapse
|
7
|
Chua YZ, Young-Gonzales AR, Richert R, Ediger MD, Schick C. Dynamics of supercooled liquid and plastic crystalline ethanol: Dielectric relaxation and AC nanocalorimetry distinguish structural α- and Debye relaxation processes. J Chem Phys 2018; 147:014502. [PMID: 28688431 DOI: 10.1063/1.4991006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Physical vapor deposition has been used to prepare glasses of ethanol. Upon heating, the glasses transformed into the supercooled liquid phase and then crystallized into the plastic crystal phase. The dynamic glass transition of the supercooled liquid is successfully measured by AC nanocalorimetry, and preliminary results for the plastic crystal are obtained. The frequency dependences of these dynamic glass transitions observed by AC nanocalorimetry are in disagreement with conclusions from previously published dielectric spectra of ethanol. Existing dielectric loss spectra have been carefully re-evaluated considering a Debye peak, which is a typical feature in the dielectric loss spectra of monohydroxy alcohols. The re-evaluated dielectric fits reveal a prominent dielectric Debye peak, a smaller and asymmetrically broadened peak, which is identified as the signature of the structural α-relaxation and a Johari-Goldstein secondary relaxation process. This new assignment of the dielectric processes is supported by the observation that the AC nanocalorimetry dynamic glass transition temperature, Tα, coincides with the dielectric structural α-relaxation process rather than the Debye process. The combined results from dielectric spectroscopy and AC nanocalorimetry on the plastic crystal of ethanol suggest the occurrence of a Debye process also in the plastic crystal phase.
Collapse
Affiliation(s)
- Y Z Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - A R Young-Gonzales
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, USA
| | - R Richert
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, USA
| | - M D Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - C Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| |
Collapse
|
8
|
Beasley MS, Tylinski M, Chua YZ, Schick C, Ediger MD. Glasses of three alkyl phosphates show a range of kinetic stabilities when prepared by physical vapor deposition. J Chem Phys 2018; 148:174503. [DOI: 10.1063/1.5026505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. S. Beasley
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M. Tylinski
- Department of Chemistry, Widener University, Chester, Pennsylvania 19013, USA
| | - Y. Z. Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Center CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - C. Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Center CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| |
Collapse
|
9
|
Abstract
The pathway of crystal nucleation significantly influences the structure and properties of semi-crystalline polymers. Crystal nucleation is normally heterogeneous at low supercooling, and homogeneous at high supercooling, of the polymer melt. Homogeneous nucleation in bulk polymers has been, so far, hardly accessible experimentally, and was even doubted to occur at all. This topical review summarizes experimental findings on homogeneous crystal nucleation in polymers. Recently developed fast scanning calorimetry, with cooling and heating rates up to 106 K s-1, allows for detailed investigations of nucleation near and even below the glass transition temperature, including analysis of nuclei stability. As for other materials, the maximum homogeneous nucleation rate for polymers is located close to the glass transition temperature. In the experiments discussed here, it is shown that polymer nucleation is homogeneous at such temperatures. Homogeneous nucleation in polymers is discussed in the framework of the classical nucleation theory. The majority of our observations are consistent with the theory. The discrepancies may guide further research, particularly experiments to progress theoretical development. Progress in the understanding of homogeneous nucleation is much needed, since most of the modelling approaches dealing with polymer crystallization exclusively consider homogeneous nucleation. This is also the basis for advancing theoretical approaches to the much more complex phenomena governing heterogeneous nucleation.
Collapse
Affiliation(s)
- C Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany. Faculty of Interdisciplinary Research, Competence Centre CALOR, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany. Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russia
| | | | | |
Collapse
|
10
|
Tylinski M, Beasley MS, Chua YZ, Schick C, Ediger MD. Limited surface mobility inhibits stable glass formation for 2-ethyl-1-hexanol. J Chem Phys 2017; 146:203317. [DOI: 10.1063/1.4977787] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. Tylinski
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| | - M. S. Beasley
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| | - Y. Z. Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - C. Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| |
Collapse
|
11
|
Chua YZ, Zorn R, Holderer O, Schmelzer JWP, Schick C, Donth E. Temperature fluctuations and the thermodynamic determination of the cooperativity length in glass forming liquids. J Chem Phys 2017; 146:104501. [PMID: 28298119 DOI: 10.1063/1.4977737] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The aim of this paper is to decide which of the two possible thermodynamic expressions for the cooperativity length in glass forming liquids is the correct one. In the derivation of these two expressions, the occurrence of temperature fluctuations in the considered nanoscale subsystems is either included or neglected. Consequently, our analysis gives also an answer to the widely discussed problem whether temperature fluctuations have to be generally accounted for in thermodynamics or not. To this end, the characteristic length-scales at equal times and temperatures for propylene glycol were determined independently from AC calorimetry in both the above specified ways and from quasielastic neutron scattering (QENS), and compared. The result shows that the cooperative length determined from QENS coincides most consistently with the cooperativity length determined from AC calorimetry measurements for the case that the effect of temperature fluctuations is incorporated in the description. This conclusion indicates that-accounting for temperature fluctuations-the characteristic length can be derived by thermodynamic considerations from the specific parameters of the liquid at glass transition and that temperature does fluctuate in small systems.
Collapse
Affiliation(s)
- Y Z Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany
| | - R Zorn
- Jülich Centre for Neutron Science, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - O Holderer
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85748 Garching, Germany
| | - J W P Schmelzer
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany
| | - C Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany
| | - E Donth
- Wachbergstr. 3, 01326 Dresden, Germany
| |
Collapse
|
12
|
Zhuravlev E, Schmelzer JWP, Androsch R, Schick C. Experimental Test of Tammann's Nuclei Development Approach in Crystallization of Macromolecules. INT POLYM PROC 2016. [DOI: 10.3139/217.3246] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Prediction of the supermolecular structure and with that of properties of crystallizable polymers requires in-depth knowledge about the crystallization behavior, in particular the temperature-dependence of the nucleation kinetics. Typically, at low supercooling of the melt the nucleation rate/nuclei density often is assessed by optical microscopy, through an analysis of the evolution of the spherulitic superstructure. This approach fails if the nuclei density is too high, or if nuclei formation is not followed by growth due to chain-mobility constraints. In such cases, Tammann's two-stage crystal nuclei development method can be applied. It includes the formation of crystal nuclei at high supercooling of the melt, and their detection at higher temperature, after their growth to crystals. Though initially developed for analysis of low molecular mass compounds, this approach has recently also successfully been employed for analysis of the nucleation behavior of polymers, which is demonstrated here on the examples of poly (L-lactic acid) (PLLA), and poly (∊-caprolactone) (PCL). While in case of PLLA the ability to gain information about isothermal and non-isothermal nucleation is explained, in case of PCL new information about the thermal stability of nuclei is presented. The importance of such analyses in the context of understanding structure formation of polymers at processing-relevant cooling conditions is discussed.
Collapse
Affiliation(s)
- E. Zhuravlev
- Institute of Physics , University of Rostock, Rostock , Germany
- Competence Centre CALOR , Faculty of Interdisciplinary Research, University of Rostock, Rostock , Germany
| | | | - R. Androsch
- Center of Engineering Sciences , Martin Luther University Halle-Wittenberg, Halle/Saale , Germany
| | - C. Schick
- Institute of Physics , University of Rostock, Rostock , Germany
- Competence Centre CALOR , Faculty of Interdisciplinary Research, University of Rostock, Rostock , Germany
| |
Collapse
|
13
|
Tylinski M, Chua YZ, Beasley MS, Schick C, Ediger MD. Vapor-deposited alcohol glasses reveal a wide range of kinetic stability. J Chem Phys 2016; 145:174506. [DOI: 10.1063/1.4966582] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- M. Tylinski
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| | - Y. Z. Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - M. S. Beasley
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| | - C. Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| |
Collapse
|
14
|
Abstract
Physical vapor deposition (PVD) has been used to prepare organic glasses with very high kinetic stability and it has been suggested that molecular anisotropy is a prerequisite for stable glass formation. Here we use PVD to prepare glasses of tetrachloromethane, a simple organic molecule with a nearly isotropic molecular structure. In situ AC nanocalorimetry was used to characterize the vapor-deposited glasses. Glasses of high kinetic stability were produced by deposition near 0.8 Tg. The isothermal transformation of the vapor-deposited glasses into the supercooled liquid state gave further evidence that tetrachloromethane forms glasses with high kinetic stability, with the transformation time exceeding the structural relaxation time of the supercooled liquid by a factor of 10(3). The glass transition temperature of liquid-cooled tetrachloromethane is determined as Tg ≈ 78 K, which is different from previously reported values. The frequency dependence of the glass transition was also determined and the fragility was estimated as m ≈ 118. The successful formation of PVD glasses of tetrachloromethane which have high kinetic stability argues that molecular asymmetry is not a prerequisite for stable glass formation.
Collapse
Affiliation(s)
- Y Z Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18059 Rostock, Germany
| | - M Tylinski
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - S Tatsumi
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - M D Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - C Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18059 Rostock, Germany
| |
Collapse
|
15
|
Gradys A, Sajkiewicz P, Zhuravlev E, Schick C. Kinetics of isothermal and non-isothermal crystallization of poly(vinylidene fluoride) by fast scanning calorimetry. POLYMER 2016. [DOI: 10.1016/j.polymer.2015.11.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
16
|
Tylinski M, Sepúlveda A, Walters DM, Chua YZ, Schick C, Ediger MD. Vapor-deposited glasses of methyl-m-toluate: How uniform is stable glass transformation? J Chem Phys 2015; 143:244509. [PMID: 26723694 DOI: 10.1063/1.4938420] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
AC chip nanocalorimetry is used to characterize vapor-deposited glasses of methyl-m-toluate (MMT). Physical vapor deposition can prepare MMT glasses that have lower heat capacity and significantly higher kinetic stability compared to liquid-cooled glasses. When heated, highly stable MMT glasses transform into the supercooled liquid via propagating fronts. We present the first quantitative analysis of the temporal and spatial uniformities of these transformation fronts. The front velocity varies by less than 4% over the duration of the transformation. For films 280 nm thick, the transformation rates at different spatial positions in the film differ by about 25%; this quantity may be related to spatially heterogeneous dynamics in the stable glass. Our characterization of the kinetic stability of MMT stable glasses extends previous dielectric experiments and is in excellent agreement with these results.
Collapse
Affiliation(s)
- M Tylinski
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - A Sepúlveda
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Diane M Walters
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Y Z Chua
- Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany
| | - C Schick
- Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany
| | - M D Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| |
Collapse
|
17
|
Borgeat A, Schick C, Votta-Velis G. Pharmacologic Factors: Anaesthetic Agents that May Influence Cancer Outcomes: Local Anaesthetics. Curr Anesthesiol Rep 2015. [DOI: 10.1007/s40140-015-0112-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
18
|
Chua YZ, Ahrenberg M, Tylinski M, Ediger MD, Schick C. How much time is needed to form a kinetically stable glass? AC calorimetric study of vapor-deposited glasses of ethylcyclohexane. J Chem Phys 2015; 142:054506. [PMID: 25662653 DOI: 10.1063/1.4906806] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Glasses of ethylcyclohexane produced by physical vapor deposition have been characterized by in situ alternating current chip nanocalorimetry. Consistent with previous work on other organic molecules, we observe that glasses of high kinetic stability are formed at substrate temperatures around 0.85 Tg, where Tg is the conventional glass transition temperature. Ethylcyclohexane is the least fragile organic glass-former for which stable glass formation has been established. The isothermal transformation of the vapor-deposited glasses into the supercooled liquid state was also measured. At seven substrate temperatures, the transformation time was measured for glasses prepared with deposition rates across a range of four orders of magnitude. At low substrate temperatures, the transformation time is strongly dependent upon deposition rate, while the dependence weakens as Tg is approached from below. These data provide an estimate for the surface equilibration time required to maximize kinetic stability at each substrate temperature. This surface equilibration time is much smaller than the bulk α-relaxation time and within two orders of magnitude of the β-relaxation time of the ordinary glass. Kinetically stable glasses are formed even for substrate temperatures below the Vogel and the Kauzmann temperatures. Surprisingly, glasses formed in the limit of slow deposition at the lowest substrate temperatures are not as kinetically stable as those formed near 0.85 Tg.
Collapse
Affiliation(s)
- Y Z Chua
- Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany
| | - M Ahrenberg
- Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany
| | - M Tylinski
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M D Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - C Schick
- Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany
| |
Collapse
|
19
|
Wurm A, Merzlyakov M, Schick C. Reversible melting probed by temperature modulated dynamic mechanical and calorimetric measurements. Colloid Polym Sci 2014. [DOI: 10.1007/s003960050242] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
20
|
Schmidt C, Beck M, Ahrenberg M, Schick C, Keßler O, Kragl U. Room temperature ionic liquids in a heat treatment process for metals. RSC Adv 2014. [DOI: 10.1039/c4ra06901c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
21
|
Kolbe M, Weiss M, Schick C, Marty A, Dambach M, Grote G, Grande B. Board 356 - Research Abstract The Magic of the Inquiry. Simul Healthc 2013. [DOI: 10.1097/01.sih.0000441608.02534.aa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
22
|
Shoifet E, Chua YZ, Huth H, Schick C. High frequency alternating current chip nano calorimeter with laser heating. Rev Sci Instrum 2013; 84:073903. [PMID: 23902080 DOI: 10.1063/1.4812349] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Heat capacity spectroscopy at frequencies up to 100 kHz is commonly performed by thermal effusivity measurements applying the 3ω-technique. Here we show that AC-calorimetry using a thin film chip sensor allows for the measurement of frequency dependent heat capacity in the thin film limit up to about 1 MHz. Using films thinner than the thermal length of the thermal wave (~1 μm) at such frequencies is advantageous because it provides heat capacity alone and not in combination with other quantities like thermal conductivity, at least on a qualitative basis. The used calorimetric sensor and the sample are each less than 1 μm thick. For high frequency AC-calorimetry, high cooling rates at very small temperature differences are required. This is realized by minimizing the heated spot to the size of the on chip thermocouple (3 × 6 μm(2)). A modulated laser beam shaped and positioned by a glass fiber is used as the heat source. The device was used to measure the complex heat capacity in the vicinity of the dynamic glass transition (structural relaxation) of poly(methyl methacrylate). Combining different calorimeters finally provides data between 10(-3) Hz and 10(6) Hz. In this frequency range the dynamic glass transition shifts about 120 K.
Collapse
Affiliation(s)
- E Shoifet
- Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany
| | | | | | | |
Collapse
|
23
|
Milkereit B, Jonas L, Schick C, Keßler O. Das kontinuierliche Zeit-Temperatur-Ausscheidungs-Diagramm einer Aluminiumlegierung EN AW-6005A*. ACTA ACUST UNITED AC 2013. [DOI: 10.3139/105.110056] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Kurzfassung
Der Einfluss der Abschreckgeschwindigkeit auf das Ausscheidungsverhalten von Aluminiumlegierungen wird, in Anlehnung an ZTU-Diagramme von Stählen, in kontinuierlichen Zeit-Temperatur-Ausscheidungs-Diagrammen dargestellt. Solche Diagramme sind bisher kaum verfügbar, können jetzt aber mit Hilfe der Differential Scanning Calorimetry (DSC) erfasst werden. Wird eine Charge der Aluminiumlegierung EN AW-6005A in einem Kühlgeschwindigkeitsbereich von 0,1–30 K/min von Lösungsglühbedingungen in einem DSC abgekühlt, sind in den Abkühlkurven zwei exotherme Ausscheidungsreaktionen zu erkennen, eine Hoch- sowie eine Niedertemperaturreaktion. Um Aufschluss darüber zu erhalten, welche Phasen dabei ausgeschieden werden, wurden umfangreiche Gefügeanalysen mittels Licht- und Rasterelektronenmikroskopie, energiedispersiver Röntgen-Mikroanalyse (EDX), Röntgendiffraktometrie (XRD) und Elektronen-Rückstreubeugung (EBSD) sowie Härteprüfungen an unterschiedlich abgekühlten Proben durchgeführt. Es konnte gezeigt werden, dass bei der Hochtemperaturreaktion Mg2Si ausgeschieden wird. Die Keimbildung der Mg2Si-Partikel erfolgt überwiegend heterogen an Primärausscheidungen.
Collapse
Affiliation(s)
- B. Milkereit
- Universität Rostock, Fakultät für Maschinenbau und Schiffstechnik, Lehrstuhl für Werkstofftechnik
| | - L. Jonas
- Universität Rostock, Medizinische Fakultät, Institut für Pathologie, Elektronenmikroskopisches Zentrum
| | - C. Schick
- Universität Rostock, Mathematisch-Naturwissenschaftliche Fakultät, Institut für Physik, Arbeitsgruppe Polymerphysik
| | - O. Keßler
- Universität Rostock, Fakultät für Maschinenbau und Schiffstechnik, Lehrstuhl für Werkstofftechnik
| |
Collapse
|
24
|
Yang B, Abyzov AS, Zhuravlev E, Gao Y, Schmelzer JWP, Schick C. Size and rate dependence of crystal nucleation in single tin drops by fast scanning calorimetry. J Chem Phys 2013; 138:054501. [DOI: 10.1063/1.4789447] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
25
|
Ahrenberg M, Chua YZ, Whitaker KR, Huth H, Ediger MD, Schick C. In situinvestigation of vapor-deposited glasses of toluene and ethylbenzene via alternating current chip-nanocalorimetry. J Chem Phys 2013; 138:024501. [DOI: 10.1063/1.4773354] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
|
26
|
Ahrenberg M, Shoifet E, Whitaker KR, Huth H, Ediger MD, Schick C. Differential alternating current chip calorimeter for in situ investigation of vapor-deposited thin films. Rev Sci Instrum 2012; 83:033902. [PMID: 22462933 DOI: 10.1063/1.3692742] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Physical vapor deposition can be used to produce thin films with interesting material properties including extraordinarily stable organic glasses. We describe an ac chip calorimeter for in situ heat capacity measurements of as-deposited nanometer thin films of organic glass formers. The calorimetric system is based on a differential ac chip calorimeter which is placed in the vacuum chamber for physical vapor deposition. The sample is directly deposited onto one calorimetric chip sensor while the other sensor is protected against deposition. The device and the temperature calibration procedure are described. The latter makes use of the phase transitions of cyclopentane and the frequency dependence of the dynamic glass transition of toluene and ethylbenzene. Sample thickness determination is based on a finite element modeling of the sensor sample arrangement. In the modeling, a layer of toluene was added to the sample sensor and its thickness was varied in an iterative way until the model fit the experimental data.
Collapse
Affiliation(s)
- M Ahrenberg
- Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany
| | | | | | | | | | | |
Collapse
|
27
|
El-Taweel SH, Stoll B, Schick C. Crystallization kinetics and miscibility of blends of polyhydroxybutyrate (PHB) with ethylene vinyl acetate copolymers (EVA). e-Polymers 2011. [DOI: 10.1515/epoly.2011.11.1.191] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractA series of ethylene vinyl acetate random copolymer EVA, with vinyl acetate (VA) varied from 9 to 91m%, was investigated by differential scanning calorimetry DSC and polarized optical microscopy. Biodegradable polymer blends of polyhydroxybutyrate PHB and EVA, having VA in EVA in range from 40m% till 91m%, were prepared by film casting from a chloroform solution. The miscibility and crystallization behavior of these blends were investigated. The isothermal crystallization behaviors of PHB and PHB/EVA blends are discussed in terms of the half time of crystallization t1/2. Experimental results indicated that blends of PHB/ EVA91 are completely miscible blend in the entire (0 to 100 m%) compositional ranges. Blends PHB/ EVA, for VA varied from 40 till 70 m% are immiscible as evidenced by the existence of unchanged composition independent glass transition temperatures (Tg), crystallization and melting behavior. The isothermal crystallization of PHB blends was investigated from room temperature till 130 °C. 80 °C was found to be the best temperature for comparison of different blends. At 80 °C t1/2 strongly depends on the content of VA in PHB/EVA blend, mainly due to differences in miscibility as well as due to differences in segmental mobility as identified by differences in glass transition temperature. Since both components in PHB/EVA80, pure PHB and pure EVA80, have glass transition temperatures close to 0 °C, it is difficult to decide its miscibility from Tg. However from the strong dependence of the value of crystallization half time t1/2 of PHB/EVA80 on blend composition, it was possible to reasonably infer that PHB/EVA80 is partially miscible.
Collapse
Affiliation(s)
- S. H. El-Taweel
- 1Engineering and materials science department, Faculty of Engineering and Materials science, German University in Cairo –GUC, New Cairo City - Main Entrance Al Tagamoa Al Khames, Egypt
- 2On leave of Chemistry department, Faculty of science, Cairo University, Orman, Giza, Egypt
| | - B. Stoll
- 3Engineering and materials science department, Faculty of Engineering and Materials science, German University in Cairo –GUC, New Cairo City - Main Entrance Al Tagamoa Al Khames, Egypt
| | - C. Schick
- 4Universität Rostock, Institut für Physik, Wismarsche Str. 43-45, 18051 Rostock, Germany
| |
Collapse
|
28
|
Emel’yanenko VN, Verevkin SP, Schick C, Stepurko EN, Roganov GN, Georgieva MK. The thermodynamic properties of S-lactic acid. Russ J Phys Chem 2010. [DOI: 10.1134/s0036024410090074] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
29
|
|
30
|
Weber T, Cammerer G, Schick C, Solbach C, Hillenbrand A, Barth TF, Henne-Bruns D, Blagieva R, Böhm BO, Reske SN, Luster M. C-11 methionine positron emission tomography/computed tomography localizes parathyroid adenomas in primary hyperparathyroidism. Horm Metab Res 2010; 42:209-14. [PMID: 20013649 DOI: 10.1055/s-0029-1243185] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In patients with primary hyperparathyroidism (pHPT), positive preoperative localization studies enable to perform a minimally invasive approach for parathyroid surgery. However, current imaging techniques are not always successful. We therefore conducted a study to determine the sensitivity of C-11 methionine positron emission tomography/computed tomography (Met-PET/CT) in localizing parathyroid adenomas in pHPT. Met-PET/CT scans of the neck and mediastinum of 33 patients undergoing parathyroidectomy for primary HPT were compared with intraoperative and histological findings. Primary HPT was caused by a single gland adenoma in 30 patients, while another 3 patients had multiglandular disease. Met-PET/CT scan correctly located a single gland adenoma in 25 out of 30 (83%) patients with pHPT, among them 2 patients with persistent disease, 7 patients with prior neck surgery, and 8 patients with concomitant thyroid nodules. In 3 patients with multiglandular disease, Met-PET/CT showed only one enlarged parathyroid gland in two individuals and was negative in the third patient. Statistical analysis found a significant correlation between true-positive results and the weight (2.42+/-4.05 g) and diameter (2.0+/-1.18 cm) of parathyroid adenomas while the subgroup with false negative findings had significantly smaller (0.98+/-0.54 cm) and lighter (0.5+/-0.38 g) glands. Sensitivity was 83% for single gland adenomas and 67% for multiglandular disease. Met-PET/CT correctly localized 83% of single gland parathyroid adenomas in patients with pHPT. However, preoperative localization of multiglandular disease due to double adenomas or parathyroid hyperplasia remained difficult.
Collapse
Affiliation(s)
- T Weber
- Department of Surgery, University Medical Center, Ulm, Germany.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
|
32
|
Affiliation(s)
- A. Serghei
- Institute for Experimental Physics I, University of Leipzig, 04103 Leipzig, Germany, and Physics Department, University of Rostock, 18051 Rostock, Germany
| | - H. Huth
- Institute for Experimental Physics I, University of Leipzig, 04103 Leipzig, Germany, and Physics Department, University of Rostock, 18051 Rostock, Germany
| | - C. Schick
- Institute for Experimental Physics I, University of Leipzig, 04103 Leipzig, Germany, and Physics Department, University of Rostock, 18051 Rostock, Germany
| | - F. Kremer
- Institute for Experimental Physics I, University of Leipzig, 04103 Leipzig, Germany, and Physics Department, University of Rostock, 18051 Rostock, Germany
| |
Collapse
|
33
|
Minakov AA, Wurm A, Schick C. Superheating in linear polymers studied by ultrafast nanocalorimetry. Eur Phys J E Soft Matter 2007; 23:43-53. [PMID: 17510749 DOI: 10.1140/epje/i2007-10173-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Accepted: 04/25/2007] [Indexed: 05/15/2023]
Abstract
To study phase transition kinetics on submillisecond time scale a sensitive ultrafast nanocalorimeter was constructed. Controlled ultrafast cooling, as well as heating, up to 10(6) K/s was attained. The method was applied for the measurements of the superheating phenomenon in a set of linear polymers: iPS, PBT, PET, and iPP. A power law relation between the superheating and the heating rate holds in the heating rate range 10(-2) - 10(4) K/s. A limiting superheating of about 10% of the melting temperature was observed at rates above 10(4) - 10(5) K/s. This limit depends on annealing conditions before sample melting. The observed superheating limit, as well as the power law, can be accounted for the internal stresses near the crystalline amorphous interface in semicrystalline polymers induced by heating, which are related to the thermal expansion gradients inherent in a semicrystalline material.
Collapse
Affiliation(s)
- A A Minakov
- University of Rostock, Institute of Physics, Universitätsplatz 3, 18051 Rostock, Germany
| | | | | |
Collapse
|
34
|
Merzlyakov M, Wurm A, Zorzut M, Schick C. Frequency and temperature amplitude dependence of complex heat capacity in the melting region of polymers. J MACROMOL SCI B 2006. [DOI: 10.1080/00222349908248158] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- M. Merzlyakov
- a University of Rostock, Department of Physics , Universitaetsplatz 3, D-18051, Rostock, Germany
- b General Physics Institute , Moscow, Russia
| | - A. Wurm
- a University of Rostock, Department of Physics , Universitaetsplatz 3, D-18051, Rostock, Germany
| | - M. Zorzut
- a University of Rostock, Department of Physics , Universitaetsplatz 3, D-18051, Rostock, Germany
- c Trieste University , Trieste, Italy
| | - C. Schick
- a University of Rostock, Department of Physics , Universitaetsplatz 3, D-18051, Rostock, Germany
| |
Collapse
|
35
|
Affiliation(s)
- A. Wurm
- a University of Rostock, Department of Physics , Universitätsplatz 3, D-18051, Rostock, Germany
| | - M. Merzlyakov
- a University of Rostock, Department of Physics , Universitätsplatz 3, D-18051, Rostock, Germany
- b General Physics Institute , Moscow, Russia
| | - C. Schick
- a University of Rostock, Department of Physics , Universitätsplatz 3, D-18051, Rostock, Germany
| |
Collapse
|
36
|
Tol R, Minakov A, Adamovsky S, Mathot V, Schick C. Metastability of polymer crystallites formed at low temperature studied by ultra fast calorimetry: Polyamide 6 confined in sub-micrometer droplets vs. bulk PA6. POLYMER 2006. [DOI: 10.1016/j.polymer.2006.01.052] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
37
|
|
38
|
Pyda M, Nowak-Pyda E, Heeg J, Huth H, Minakov AA, Di Lorenzo ML, Schick C, Wunderlich B. Melting and crystallization of poly(butylene terephthalate) by temperature-modulated and superfast calorimetry. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20789] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
39
|
Jansen MAG, Goossens JGP, de Wit G, Bailly C, Schick C, Koning CE. Poly(butylene terephthalate) Copolymers Obtained via Solid-State Polymerization and Melt Polymerization. A Study on the Microstructure via 13C NMR Sequence Distribution. Macromolecules 2005. [DOI: 10.1021/ma051440j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. A. G. Jansen
- Laboratory of Polymer Technology, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratory of Polymer Chemistry, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratoire de Chimie et de Physique des Hauts Polymères, Université Catholique de Louvain, Place Croix du Sud, 1 B-1348 Louvain-la-Neuve, Belgium, Institute of Physics, University
| | - J. G. P. Goossens
- Laboratory of Polymer Technology, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratory of Polymer Chemistry, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratoire de Chimie et de Physique des Hauts Polymères, Université Catholique de Louvain, Place Croix du Sud, 1 B-1348 Louvain-la-Neuve, Belgium, Institute of Physics, University
| | - G. de Wit
- Laboratory of Polymer Technology, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratory of Polymer Chemistry, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratoire de Chimie et de Physique des Hauts Polymères, Université Catholique de Louvain, Place Croix du Sud, 1 B-1348 Louvain-la-Neuve, Belgium, Institute of Physics, University
| | - C. Bailly
- Laboratory of Polymer Technology, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratory of Polymer Chemistry, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratoire de Chimie et de Physique des Hauts Polymères, Université Catholique de Louvain, Place Croix du Sud, 1 B-1348 Louvain-la-Neuve, Belgium, Institute of Physics, University
| | - C. Schick
- Laboratory of Polymer Technology, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratory of Polymer Chemistry, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratoire de Chimie et de Physique des Hauts Polymères, Université Catholique de Louvain, Place Croix du Sud, 1 B-1348 Louvain-la-Neuve, Belgium, Institute of Physics, University
| | - C. E. Koning
- Laboratory of Polymer Technology, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratory of Polymer Chemistry, Faculty of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands, Laboratoire de Chimie et de Physique des Hauts Polymères, Université Catholique de Louvain, Place Croix du Sud, 1 B-1348 Louvain-la-Neuve, Belgium, Institute of Physics, University
| |
Collapse
|
40
|
Serghei A, Mikhailova Y, Huth H, Schick C, Eichhorn KJ, Voit B, Kremer F. Molecular dynamics of hyperbranched polyesters in the confinement of thin films. Eur Phys J E Soft Matter 2005; 17:199-202. [PMID: 15912265 DOI: 10.1140/epje/i2005-10009-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Accepted: 04/05/2005] [Indexed: 05/02/2023]
Abstract
Broadband Dielectric Spectroscopy is employed to investigate the molecular dynamics in thin films of hyperbranched polyesters (type AB(1)B(2), with -OH and -OCOCH(3) as terminal groups). Three relaxation processes are detected: alpha, beta and gamma. While the latter two are not influenced by the confinement, a pronounced effect is observed on the alpha relaxation: with decreasing film thickness the slower relaxation modes of the dynamic glass transition are gradually suppressed, resulting in an increase of the average relaxation rate and in a linear decrease of the dielectric strength. This is attributed to an immobilization in confinement of the polymeric segments located at the periphery of the hyperbranched macromolecular structures.
Collapse
Affiliation(s)
- A Serghei
- Leipzig University, Institute for Experimental Physics I, Leipzig, Germany.
| | | | | | | | | | | | | |
Collapse
|
41
|
Serghei A, Huth H, Schellenberger M, Schick C, Kremer F. Pattern formation in thin polystyrene films induced by an enhanced mobility in ambient air. Phys Rev E Stat Nonlin Soft Matter Phys 2005; 71:061801. [PMID: 16089755 DOI: 10.1103/physreve.71.061801] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Revised: 02/11/2005] [Indexed: 05/03/2023]
Abstract
Thin polystyrene films (prepared in a sandwich geometry between two aluminum electrodes) develop a characteristic pattern in ambient air when kept above the glass-transition temperature, whereas they remain unchanged in vacuum or in a pure nitrogen atmosphere. Measurements by broadband dielectric spectroscopy, capacitive dilatometry, and AC calorimetry reveal that the pattern formation is initiated in ambient air by an increase in the average relaxation rate of the dynamic glass transition, which results in a corresponding reduction of the glass-transition temperature. Infrared measurements evidence that this is caused by a shift of the molecular weight distribution to lower values as a consequence of oxygen-induced chain scissions.
Collapse
Affiliation(s)
- A Serghei
- Institute for Experimental Physics I, University of Leipzig, 04013 Leipzig, Germany
| | | | | | | | | |
Collapse
|
42
|
|
43
|
Rastogi R, Vellinga WP, Rastogi S, Schick C, Meijer HEH. The three-phase structure and mechanical properties of poly(ethylene terephthalate). ACTA ACUST UNITED AC 2004. [DOI: 10.1002/polb.20096] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
44
|
Vogl T, Schick C, Mack M, Gstöttner W. Bildgebende Diagnostik und Differentialdiagnostik von pathologischen Prozessen des Sinus cavernosus. ROFO-FORTSCHR RONTG 2004. [DOI: 10.1055/s-2004-827447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
45
|
Abstract
To describe the different imaging modalities for the evaluation of pathological changes in the cavernous sinus as well as to compile criteria for differential diagnosis. Imaging of the cavernous sinus comprises the primary use of tomographic modalities such as CT or MRI. The continuing development of multislice-CT (MSCT) allows the depiction of bony structures of the cavernous sinus with a high resolution.Secondary reconstructions of the acquired data set allow a reliable evaluation especially of the bony topography including the foraminae of nerves and vessels. Uni- or bilateral structures can be visualized using contrast-enhanced CT.CT-angiography is capable of demonstrating the course of the internal carotid artery and its involvement in pathologies of the cavernous sinus, this recent achievement has only been made available by use of the current short scanning times. Contrast-enhanced MRI in axial and coronal orientation, optionally using fat saturation techniques as well as arterial and venous MRI-angiography (MRA) are used to depict the soft parts of the cavernous sinus. Care must be taken to cover all topographic detail including different signal intensities, as multiple inborn, neoplastic, infectious or traumatic changes can be present hampering the radiologic diagnosis of the cavernous sinus. Uni- and bilateral infiltration of the cavernous sinus as well as vascular involvement represent additional criteria leading to the differential diagnosis. The advent of dynamic sequences as well as diffusion and perfusion weighted MRI have broadened the spectrum of diagnostic modalities. Digital subtraction angiography as an invasive technique is used during therapeutic procedures such as the local treatment of aneurysms or carotid-cavernous fistulas.
Collapse
Affiliation(s)
- T J Vogl
- Institut für diagnostische und interventionelle Radiologie, Johann-Wolfgang-Goethe-Universität Frankfurt/Main.
| | | | | | | |
Collapse
|
46
|
Rödel F, Hoffmann J, Haas J, Grabenbauer G, Schick C, Günther K, Sauer R, Rödel C. Expression of survivin in rectal cancer is inversely correlated to apoptosis in-vitro and in-vivo and may predict tumor response to neoadjuvant radiochemotherapy. Int J Radiat Oncol Biol Phys 2002. [DOI: 10.1016/s0360-3016(02)03229-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
47
|
Jacobi V, Thalhammer A, Schick C, Peters J, Vogl T. Notched ureter sign. Eur Radiol 2002; 12:2120-2. [PMID: 12211179 DOI: 10.1007/s00330-002-1348-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- V Jacobi
- Institut für Diagnostische und Interventionelle Radiologie, Zentrum der Radiologie, Klinikum d. J.W. Goethe-Universität, Frankfurt/Main, Germany
| | | | | | | | | |
Collapse
|
48
|
Abolmaali N, Langenfeld M, Krahforst R, Schick C, Thalhammer A, Schmitt J, Schulze T, Schächinger V, Vogl TJ. Vessel wall MRI of the thoracic aorta: correlation to histology and transesophageal ultrasound. Preliminary results. ROFO-FORTSCHR RONTG 2002; 174:568-72. [PMID: 11997855 DOI: 10.1055/s-2002-28272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE To visualise the vessel wall of the descending thoracic aorta using magnetic resonance imaging. To evaluate the diagnostic potential of tailored T1-weighted sequences with contrast enhancement to assess systemic atherosclerotic disease. METHODS This study was performed on a clinical 1.5 Tesla scanner using a gradient strength of 30 mT/m and the phased array spine coil. A cadaver was examined to optimise a magnetic resonance imaging (MRI) protocol to evaluate atherosclerotic aortic wall disease. The acquired MR images were compared to gross specimens and histology. Subsequently seven patients who had undergone transesophageal ultrasound (TEU) with detailed assessment of the descending thoracic aorta were examined with MRI. The optimised protocol included untriggered and fat suppressed T2-weighted turbo spin echo sequences and ECG-triggered and fat suppressed T1-weighted spin echo sequences before and after iv administration of Gd-DTPA. Findings of the MR images were compared to the results of TEU. Contrast enhancement measurements were performed in normal and thickened vessel wall segments. RESULTS For the cadaver study a good correlation of the degree of vessel wall thickening and the extent of plaque imaged with the applied MR protocol was found. Tissue characterisation was limited due to post mortem changes. In vivo ECG-triggered T1-weighted images showed good correlation to TEU in terms of vessel wall thickness and plaque extension as verified by means of consensus reading. Differentiation of the plaque components fat, calcium and fibrous tissue was possible. In thickened aortic wall segments and fibrous caps a mean contrast enhancement of 50.4 % +/- 23.5 % was measurable while normal wall segments showed an enhancement of 6.7 % +/- 3.1 %. The difference of contrast enhancement was highly significant (p < 0.0001). CONCLUSION Using fat suppressed T1-weighted sequences with contrast enhancement the extent of atherosclerotic vessel wall changes can be demonstrated. The suggested MR protocol contains a high potential for diagnosis and follow-up of therapy of atherosclerotic disease of the descending thoracic aorta.
Collapse
Affiliation(s)
- N Abolmaali
- Institute for Diagnostic and Interventional Radiology, Johann Wolfgang Goethe University, Frankfurt, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Schick C. Temperature modulated differential scanning calorimetry (TMDSC) – basics and applications to polymers. Applications to Polymers and Plastics 2002. [DOI: 10.1016/s1573-4374(02)80019-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
50
|
Schick C, Sukhorukov D, Schönhals A. Comparison of the Molecular Dynamics of a Liquid Crystalline Side Group Polymer Revealed from Temperature Modulated DSC and Dielectric Experiments in the Glass Transition Region. MACROMOL CHEM PHYS 2001. [DOI: 10.1002/1521-3935(20010501)202:8<1398::aid-macp1398>3.0.co;2-c] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|