Photon Density Wave Spectroscopy for Dilution‐Free Sizing of Highly Concentrated Nanoparticles During Starved‐Feed Polymerization

Optical monitoring of milk fat phase transition within homogenized fresh milk by Photon Density Wave spectroscopy

“…8a). The reduced scattering coefficient is typically evaluated in terms of inline particle sizing (Hass, Munzke, & Reich, 2010;Hass & Reich, 2011;Tanguchi et al, 2010). In this investigation however, the reduced scattering coefficient represents the structural changes of the dispersed particles within milk during thermal processing.…”

“…The resulting complex electric signal is then analysed by the VNA in terms of phase and amplitude. Further components of the spectrometer itself are described elsewhere in detail (Hass & Reich, 2011). The modulation frequency was varied between 10 and 1300 MHz, with 21 equally spaced frequencies.…”

Industrial applications of Photon Density Wave spectroscopy for in-line particle sizing [Invited]

“…The PDW spectrometer is described in more detail elsewhere [6]. Its principle components and technical features are: a vector network analyzer (VNA) (ZVA 8, Rohde & Schwarz GmbH & Co. KG, München, Germany) generates a high-frequency signal in a range of typically 10 to 1300 MHz.…”

“…The chemical process of nanoparticle synthesis can be monitored by PDW spectroscopy as well [6]. Figures 15 and 16 display the impact of emulsifier concentration on the reduced scattering coefficient and the particle size during a starved feed polymerization of a statistical copolymer, made from styrene and various acrylates.…”

“…For turbid liquid dispersions, Photon Density Wave (PDW) spectroscopy [1][2][3] provides this fundamental benefit. Recently, this technology was further developed to demonstrate its applicability to the monitoring of chemical or physical processes within liquid turbid systems [4][5][6][7].…”