Université de Fribourg

A new instrument for time-resolved static and dynamic light-scattering experiments in turbid media

Moitzi, Christian ; Vavrin, Ronny ; Bhat, Suresh Kumar ; Stradner, Anna ; Schurtenberger, Peter

In: Journal of Colloid and Interface Science, 2009, vol. 336, no. 2, p. 565-574

We present a new 3D cross-correlation instrument that not only allows for static and dynamic scattering experiments with turbid samples but measures at four angles simultaneously. It thus extends the application of cross-correlation light scattering to time-resolved studies where we can, for example, efficiently investigate the temporal evolution of aggregating or phase separating turbid...

Université de Fribourg

Cluster, glass, and gel formation and viscoelastic phase separation in aqueous clay suspensions

Shalkevich, Andrey ; Stradner, Anna ; Bhat, Suresh Kumar ; Muller, François ; Schurtenberger, Peter

In: Langmuir, 2007, vol. 23, no. 7, p. 3570 -3580

We have systematically investigated the phase diagram of clay particles in water to understand the relation between the local and macroscopic properties and the structures of clay suspensions. We focused, in particular, on sodium Cloisite (CNa) particles at concentrations typically used in nanocomposites (concentrations from 1 to 4 wt %) and at an extended range of ionic strengths (10⁻⁵ to...

Université de Fribourg

Multiple-scattering suppression in dynamic light scattering based on a digital camera detection scheme

Zakharov, Pavel ; Bhat, Suresh Kumar ; Schurtenberger, Peter ; Scheffold, Frank

In: Applied Optics, 2006, vol. 45(8), p. 1756-1764

We introduce a charge-coupled device (CCD) camera-based detection scheme in dynamic light scattering that provides information on the single-scattered autocorrelation function even for fairly turbid samples. It is based on the single focused laser beam geometry combined with the selective cross-correlation analysis of the scattered light intensity. Using a CCD camera as a multispeckle detector,...