DEVELOPMENT OF CONTINUOUSLY OPERATING TWO-DIMENSIONAL THERMAL FIELD-FLOW FRACTIONATION EQUIPMENT

Abstract

A new type of the thermal field-flow fractionation apparatus designed and constructed in the Laboratory of Analytical Chemistry provides continuous fractionation of polymers according to their molecular masses. The principle is to separate sample components into filaments from the continuous sample flow in a disk-shaped channel and to collect a sample species at the circumference of the channel. The upper wall of the channel is stationary, and the lower one rotates slowly. The method is based on a two-dimensional fractionation mechanism and demonstrates the collection of 2 polystyrene samples in a cyclohexane carrier. The method also provides a gentle fractionation environment for high polymers with low shear forces, flexible run conditions, and numerous industrial applications from special products to process quality control. The construction procedure of the complete apparatus is described with technical details.

Keywords:

• Field-flow fractionation
• Continuous fractionation
• Two-dimensional
• Separation
• Thermal gradient
• Polystyrene
• Cyclohexane
• Tetrahydrofuran

ACKNOWLEDGMENTS

We are indebted to Mr. Pekka Tarkiainen for his technical assistance from the Department of Chemistry, University of Helsinki. Funding for the project was gratefully received from the Oskar Öflund Foundation.