โ Scribed by Dieter Lehner; Gerhard Kellner; Heimo Schnablegger; Otto Glatter
No coin nor oath required. For personal study only.
ton migration (FDPM) (11,. Turbidity measurements Particle sizing of dense colloidal systems is a very practicefor the determination of size distributions of dense colloidal oriented problem. Using optical methods multiple scattering often systems (13, 14) are based on static light scattering as well makes the determination of correct particle sizes impossible. We as Fraunhofer diffraction (15); the later is typically used for introduce a new static light scattering instrument which allows particles larger than a few micrometers.
In this contribution we focus on static light scattering modification of a Fraunhofer setup featuring a flat sample cell, (SLS) in the so-called Lorenz-Mie regime. SLS is a tech-Fourier optics, and an array detection. The thickness of the flat nique well suited to determine particle radii in the range sample cell can be varied from about 10 mm to 5 mm. The small from about 50 nm up to several micrometers (16-18). We sample thickness highly reduces multiple scattering and allows for the investigation of dense colloidal systems. In most cases multiple are interested in the investigation of colloidal systems with scattering can be avoided by reducing the sample thickness only. solid or liquid particles in aqueous or organic solvents. In addition, data with remaining multiple Mie scattering can be Emulsion droplets and other spherical particles in this size inverted if the sample transmittance if above 0.3. The angular regime are often polydisperse and can be described by the regime of the instrument is 1ะ to 60ะ, the minimum measuring Lorenz-Mie theory where the optical contrast is an additime is 1 s and the smallest amount of substance necessary is about tional and essential parameter for the interpretation of scat-0.5 mL. We present our instrumentation, the evaluation technique, tering data (13,(19)(20)(21). It is possible to invert scattering and the application to latex suspensions, fat emulsions, and milk data from polydisperse spherical systems yielding particle as typical colloidal systems.
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