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New methods of temperature modulated calorimetry - benefits limitations and its relation to other dynamic methods like dielectric spectroscopy

Objective


Foreseen Results

The aim of the present project is to develop further the methods of temperature modulated calorimetry combining the knowledge of people working with different methods in different fields in different European countries and, at first, to solve some of the general questions related to the quantities determined. This work will allow to optimize the measurement conditions (including calibration) and to formulate recommendations for further optimization of the calorimeter construction. It is proposed that pilot sample calorimeters suitable for market will result from this project.
The project helps to safeguard highly qualified human resources in the countries of CCE/NIS by financial support, trainerships and scientific exchange.
The development of new materials and its industrial as well as medical applications is not possible without material characterization. Thermal Analysis and especially calorimetry is one of the very useful tools in this field. Very different types of calorimeters are on the market. Differential Scanning Calorimeters (DSC) are widely used for industrial applications.

In 1992 TA Instruments introduced a new calorimetric technique the Modulated Differential Scanning Calorimetry (MDSC). A sinusoidal temperature modulation is added to a linear heating or cooling ramp. New information on material properties are available because of the additional information from the modulated signal. There are basic differences in the extraction and calculation of the thermodynamic quantities by the different temperature modulated DSC on the market. For example there is determined the so called reversing and nonreversing heat capacity and on the other hand the complex heat capacity including real and imaginary part. The meaning of this different quantities is not yet understood. Additionally, substances and procedures for calibration of temperature modulated DSC in temperature and dynamic heat capacity are unknown.
The increasing interest in the related problems and in the interpretation of the results can be seen from the increasing number of publications and conference workshops on this topic. Because temperature modulated DSC is widely and increasing by used in industry laboratories (polymers, biopolymers, drugs, food, new materials...) as well as research laboratories it seems to be necessary to solve the general problems related to this interesting new method within an international cooperation. The present project will therefore support the comparability of measurements.

The idea of temperature modulation in calorimetry is an old one [Sullivan 1966j. In the field of low temperature calorimetry the so called AC-calorimetry is used very successful for a long time. The heat capacity can be determined high precise at well defined temperatures. Directly related to relaxation processes is the so called heat capacity spectroscopy developed by Birge and Nagel in 1986. This method results in the determination of the complex heat capacity which gives information about time dependent processes like glass transition. The photo acoustic technique, first described by Buchner 1987, as well as the impulse calorimeter, introduced by Bertman et. al in 1970 are also used to investigate the complex heat capacity in the glass transition region.

Temperature modulated calorimetry uses very different equipment and is used in very different research fields. Therefore it seems to be very attractive to organize the cooperation of scientists dealing with this different types of temperature modulated calorimeters as well as working in different fields.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Universität Rostock
Address
3,Universitätplatz
18057 Rostock
Germany

Participants (6)

DSM Research BV
Netherlands
Address
1,
6160 MD Geleen
IFA Institut für Angewandte Analysentechnik GmbH
Germany
Address
18,Schillerstraße
89077 Ulm
Institute of General Physics - Russian Academy of Sciences
Russia
Address
38,Vavilov Street
117942 Moskva
Institute of Physical Chemistry - Bulgarian Academy of Sciences
Bulgaria
Address
11,Acad.g. Bochev Street Bl.
1113 Sofia
UNIVERSITY MEDICAL SCHOOL OF PECS
Hungary
Address
12,Szigeti Ut 12
7624 Pecs
UNIVERSITY OF UMEAA
Sweden
Address

901 87 Umeaa