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SYA: Symposium Kolloide Systeme und Polyelektrolyte
SYA 4: Kolloidale Systeme und Polyelektrolyte
SYA 4.2: Poster
Monday, March 9, 1998, 18:00–20:00, P1
Optical polydispersity and contrast variation in colloidal suspensions — •Adolfo J. Banchio, Gerhard Nägele, Andrea Ferrante, and Rudolf Klein — Fakultät für Physik, Universität Konstanz, Postfach 5560, D-78434 Konstanz
We study the effect of refractive index variations on static and dynamic light scattering in strongly correlated colloidal suspensions and microemulsions which are optically and size polydisperse. The microstructure of these systems is calculated using integral equations schemes. Various models of optical polydispersity are discussed. Our calculations show that, close to an index matching point, the scattered intensity I(k) and the measurable hydrodynamic function HM(k) become very sensitive to the refractive index contrast. Various definitions of index matching points are considered. The anomalous behaviour of I(k) and HM(k) in the corresponding range of the solvent refractive index can be described by a simple approximative scheme. Consequences for scattering experiments aimed to determine size distributions or structural properties near index matching are discussed.