Affiliation:
1. 26523 Physikalisches Institut, Universität Bayreuth , D-95440 Bayreuth , Germany
Abstract
Abstract
We have developed a new double-pass optical beam deflection instrument for the measurement of diffusion, thermodiffusion and Soret coefficients in liquid mixtures. The increased sensitivity of the instrument results from a second passage of the readout laser beam through the Soret cell containing the sample. An elegant description of the total beam deflection is achieved by means of a transfer matrix formalism. The higher sensitivity allows for a reduction of the length of the detection arm and a compact and stiff design of the instrument. The performance of the new apparatus is demonstrated by its application to polymer analysis for the determination of the molar mass distribution of the polymer from the distribution of diffusion rates by means of the CONTIN algorithm.
Funder
Deutsches Zentrum für Luft- und Raumfahrt
Deutsche Forschungsgemeinschaft