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THERMAL FIELD-FLOW FRACTIONATION PRINCIPLE
Thermal
Field-Flow Fractionation is a technique which is ideally suited for the
characterization of polymers, gels and nanoparticles using different organic
solvents and to get additional chemical information about the polymers.
Different from the other Field-Flow Fractionation sub-techniques, Thermal
Field-Flow Fractionation can separate polymers not only by molar mass but
also by chemical composition at the same time. Thus, Thermal
Field-Flow Fractionation can separate two polymer fractions of different
material (e.g. PS and PMMA) but same molecular weight into independent
peaks. As the other
Field-Flow Fractionation techniques, also Thermal Field-Flow Fractionation
was invented und first published by Prof. Giddings [1].
In
Thermal Field-Flow Fractionation the separation force is established by applying
a temperature gradient. The top wall of a Thermal
Field-Flow Fractionation channel is heated up and the bottom wall of a
Thermal Field-Flow Fractionation channel is cooled. The typical temperature
difference between the cold and the hot wall used in Thermal Field-Flow
Fractionation is ranging between 20 and 100°K. By using temperature gradients a broad
molar mass range of polymer samples can be separated in Thermal Field-Flow
Fractionation analogue to the use of cross flow gradients in Flow Field-Flow
Fractionation systems.
For more information about Thermal Field-Flow Fractionation contact
Postnova Analytics via telephone, fax, email or visit our homepage
www.postnova.com
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[1] G.H. Thompson, M.N. Myers, and J.C. Giddings, "Thermal Field-Flow
Fractionation of Polystyrene Samples", Anal. Chem., 41 1219-1222 (1969).
Flow FFF |
Asymmetrical Flow Field
Flow Fractionation | Thermal FFF
| Sedimentation FFF |
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