Improved diffusing wave spectroscopy based on the automatized determination of the optical transport and absorption mean free path
- Zhang, Chi Department of Physics, University of Fribourg, Switzerland
- Reufer, Mathias LS Instruments AG, Fribourg, Switzerland
- Gaudino, Danila LS Instruments AG, Fribourg, Switzerland
- Scheffold, Frank Department of Physics, University of Fribourg, Switzerland
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01.11.2017
Published in:
- Korea-Australia Rheology Journal. - 2017, vol. 29, no. 4, p. 241–247
English
Diffusing wave spectroscopy (DWS) can be employed as an optical rheology tool with numerous applications for studying the structure, dynamics and linear viscoelastic properties of complex fluids, foams, glasses and gels. To carry out DWS measurements, one first needs to quantify the static optical properties of the sample under investigation, i.e. the transport mean free path l* and the absorption length la. In the absence of absorption this can be done by comparing the diffuse optical transmission to a calibration sample whose l* is known. Performing this comparison however is cumbersome, time consuming, and prone to mistakes by the operator. Moreover, already weak absorption can lead to significant errors. In this paper, we demonstrate the implementation of an automatized approach, based on which the DWS measurement procedure can be simplified significantly. By comparison with a comprehensive set of calibration measurements we cover the entire parameter space relating measured count rates (CRt, CRb) to (l*, la). Based on this approach we can determine l* and la of an unknown sample accurately thus making the additional measurement of a calibration sample obsolete. We illustrate the use of this approach by monitoring the coarsening of a commercially available shaving foam with DWS.
- Faculty
- Faculté des sciences et de médecine
- Department
- Département de Physique
- Language
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- English
- Classification
- Physics
- License
- License undefined
- Identifiers
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- RERO DOC 306311
- DOI 10.1007/s13367-017-0025-z
- Persistent URL
- https://folia.unifr.ch/unifr/documents/306481
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