TY  - JOUR
A1  - Bressel, Lena
A1  - Hass, Roland
A1  - Reich, O.
T1  - Particle sizing in highly turbid dispersions by Photon Density Wave
 spectroscopy
JF  - JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
N2  - Photon Density Wave (PDW) spectroscopy is presented as a fascinating technology for the independent determination of scattering (mu(s)’ and absorption (ita) properties of highly turbid liquid dispersions. The theory is reviewed introducing new expressions for the PDW coefficients k(I) and k(Phi). Furthermore, two models for dependent scattering, namely the hard sphere model in the Percus-Yevick Approximation (HSPYA) and the Yukawa model in the Mean Spherical Approximation (YMSA), are experimentally examined. On the basis of the HSPYA particle sizing is feasible in dispersions of high ionic strength. It is furthermore shown that in dialyzed dispersions or in technical copolymers with high particle charge only the YMSA allows for correct dilution-free particle sizing. (C) 2013 Elsevier Ltd. All rights reserved.
KW  - Photon Density Wave spectroscopy
KW  - Multiple light scattering
KW  - Dependent light scattering
KW  - Percus-Yevick model
KW  - Yukawa model
KW  - Particle sizing
KW  - Polymer dispersions
Y1  - 2013
U6  - https://doi.org/10.1016/j.jqsrt.2012.11.031
SN  - 0022-4073
VL  - 126
IS  - 1
SP  - 122
EP  - 129
PB  - PERGAMON-ELSEVIER SCIENCE LTD
CY  - OXFORD
ER  - 
TY  - JOUR
A1  - Hass, Roland
A1  - Münzberg, Marvin
A1  - Bressel, Lena
A1  - Reich, Oliver
T1  - Industrial applications of photon density wave spectroscopy for in-line particle sizing [Invited]
JF  - Applied optics
N2  - Optical spectroscopy in highly turbid liquid material is often restricted by simultaneous occurrence of absorption and scattering of light. Photon Density Wave (PDW) spectroscopy is one of the very few, yet widely unknown, technologies for the independent quantification of these two optical processes. Here, a concise overview about modern PDW spectroscopy is given, including all necessary equations concerning the optical description of the investigated material, dependent light scattering, particle sizing, and PDW spectroscopy itself. Additionally, it is shown how the ambiguity in particle sizing, arising from Mie theory, can be correctly solved. Due to its high temporal resolution, its applicability to highest particle concentrations, and its purely fiber-optical probe, PDW spectroscopy possesses all fundamental characteristics for optical in-line process analysis. Several application examples from the chemical industry are presented. (C) 2013 Optical Society of America
Y1  - 2013
U6  - https://doi.org/10.1364/AO.52.001423
SN  - 1559-128X
SN  - 2155-3165
VL  - 52
IS  - 7
SP  - 1423
EP  - 1431
PB  - Optical Society of America
CY  - Washington
ER  -