In: Journal of Physics: Condensed Matter, 2013, vol. 25, no. 50, p. 502101
We discuss the linear and nonlinear rheology of concentrated microscale emulsions, amorphous disordered solids composed of repulsive and deformable soft colloidal spheres. Based on recent results from simulation and theory, we derive quantitative predictions for the dependences of the elastic shear modulus and the yield stress on the droplet volume fraction. The remarkable agreement with...
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In: AIP Conference Proceedings, 2013, vol. 1518, p. 222–226
We present a rheology and light scattering study of the dynamical properties of dense emulsions at volume fractions ranging from viscous liquid to deeply jammed states. From temporally and spatially revolved dynamic light scattering we obtain detailed information about the internal dynamics. Our measurements thus allow a direct study of heterogeneous nature of the relaxation processes involved in...
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In: Physical Review A, 2014, vol. 88, no. 4, p. 043822
In the present article we substantially expand on our recent study about the fabrication of mesoscale polymeric templates of disordered photonic network materials [Haberko and Scheffold, Opt. Expr. 21, 1057 (2013)]. We present a detailed analysis and discussion of important technical aspects related to the fabrication and characterization of these fascinating materials. Compared to our initial...
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In: Advanced Optical Materials, 2014, vol. 2, no. 2, p. 115-119
The mesoscale fabrication of silicon hyperuniform disordered materials with a broad and pronounced photonic gap in the shortwave infrared is reported. Due to their unique structure and their high refractive index, these fascinating materials are predicted to possess a complete photonic bandgap in the absence of any long-range order.
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In: Physical Review Letters, 2013, vol. 111, no. 1, p. 014502
Convective motions in a fluid layer are affected by its orientation with respect to the gravitational field. We investigate the long-term stability of a thermally stressed layer of a binary liquid mixture and show that pattern formation is strongly affected by marginal inclinations as small as a few milliradians. At small Rayleigh numbers, the mass transfer is dominated by the induced large scale...
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In: Particle & Particle Systems Characterization, 2013, vol. 30, no. 7, p. 579-583
Different metal oxide particles are dye labeled by a novel and versatile approach based on aryldiazonium salt chemistry. For dye labeling the particles, the simplicity of aryldiazonium salts to be grafted onto metallic or metal oxide surface is advantageous. The salt is used as a linking agent for attaching the fluorescent molecules.
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In: Comptes Rendus Mécanique, 2013, vol. 341, no. 4–5, p. 378–385
We present preliminary near-field light scattering (NFS) data concerning the analysis of the static power spectrum and of the relaxation time constant as a function of the wave vector for non-equilibrium fluctuations (NEFs). The goal of these measurements is to obtain information about the Soret and the mass diffusion coefficients of a binary mixture undergoing thermodiffusion. In particular, we...
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In: Journal of Chemical Physics, 2012, vol. 137, no. 23, p. 234202
We use dynamic near field scattering to measure the dynamics of concentration non equilibrium fluctuations at the steady-state of Soret separation. The analysis reveals that above a threshold wave vector qc, the dynamics is governed by diffusion while at smaller wave vectors, gravity dominates. From the measurements, we extract both the mass diffusion and the Soret...
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In: Review of Scientific Instruments, 2012, vol. 83, no. 10, p. 106101
We present an implementation of the analysis of dynamic near field scattering (NFS) data using a graphics processing unit. We introduce an optimized data management scheme thereby limiting the number of operations required. Overall, we reduce the processing time from hours to minutes, for typical experimental conditions. Previously the limiting step in such experiments, the processing time is now...
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In: Optics Express, 2012, vol. 20, no. 1, p. 192-200
We propose a laser speckle based scheme that allows the analysis of local scattering properties of light diffusely reflected from turbid media. This turbid medium can be a soft material such as a colloidal or polymeric material but can also be biological tissue. The method provides a 2D map of the scattering properties of a complex, multiple scattering medium by recording a single image. We...
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