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Chapter
Single Particle Motion of Hard-Sphere-Like Polymer Micronetwork Colloids Up to the Colloid Glass Transition
Polymer micronetwork spheres swollen in a good solvent can be regarded as colloids which require no special stabilisation to avoid aggregation. Their interactions can be timed by changing the degree of interna...
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Chapter and Conference Paper
Multi-speckle autocorrelation spectroscopy — a new strategy to monitor ultraslow dynamics in dense and nonergodic media
We present a modification of the conventional dynamic light scattering set-up which allows to monitor the intensity fluctuations of many independent spatial Fourier components of the density fluctuations, i.e....
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Chapter
The effect of the internal architecture of polymer micronetwork colloids on the dynamics in highly concentrated dispersions
Motivated by the finding that colloidal dispersions of polymer micronetwork spheres with a cross-link density of 1:50 (inverse number of monomer units between crosslinks) show significant deviations from the d...
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Chapter
Development of core-shell colloids to study self-diffusion in highly concentrated dispersions
To study single particle motion in highly concentrated colloidal dispersions, a host-tracer colloid system was developed, consisting of crosslinked polymer micronetwork spheres placed in a good solvent. The ho...
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Chapter and Conference Paper
Sperhical polymer micronetwork colloids — A small-angle scattering study
Deviations of the glass transition dynamics of 1:50 crosslinked polystyrene micronetwork spheres in a good solvent with respect to hard-sphere colloids have been observed [E. Bartsch, V. Frenz, S. Möller, H. S...
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Chapter
Diffusionsvorgänge in amorphen Stoffen
Es gibt zwei wesentlich verschiedene Vorgehensweisen zur Beschreibung von Diffusionsvorgängen: Die eine führt zur Tracerdiffusion, die andere zur Interdiffusion. Zur Veranschaulichung betrachten wir eine binär...
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Article
Brownian dynamics of polydisperse colloidal hard spheres: Equilibrium structures and random close packings
Recently we presented a new technique for numerical simulations of colloidal hard-sphere systems and showed its high efficiency. Here, we extend our calculations to the treatment of both 2- and 3-dimensional m...
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Article
Brownian dynamics simulations of colloidal hard spheres. Effects of sample dimensionality on self-diffusion
The self-diffusion coefficients of colloidal hard spheres were determined by Brownian dynamics (BD) computer simulations using a new efficient algorithm for treatment of the hard-sphere interactions. Calculati...
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Chapter
Translational and Rotational Diffusion Near the Glass Transition
Diffusional transport is involved in most relaxation processes in condensed matter. In one component systems this transport is usually termed “self- diffusion” since the molecules move among themselves. Nevert...
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Article
Relaxation and phonons in viscous and glassy orthoterphenyl by neutron scattering
We present an extended set of incoherent neutron scattering measurements on the van der Waals liquido-terphenyl, obtained by time-of-flight and backscattering spectroscopy. In the supercooled liquid regime, data ...
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Chapter
Tracer diffusion in polymer and organic liquids close to the glass transition studied by forced rayleigh scattering
Translational diffusion coefficients D of photochronic dye molecules have been measured by forced Rayleigh scattering in polymer diluent systems at compositions from pure polymer to pure diluent. D could be measu...
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Article
Translational and rotational diffusion in supercooled orthoterphenyl close to the glass transition
Self diffusion coefficients in supercooled orthoterphenyl (OTP) have been determined down toD t =3·10−14 m2s−1 using a1H-NMR technique applying static field gradients up to 53T ...
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Article
Dynamic anomaly in the glass transition region of orthoterphenyl
We report on incoherent and coherent neutron scattering results in the supercooled liquid and the glassy regime of the van der Waals fluido-terphenyl using the backscattering and spin echo technique, respectively...
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Article
Spin lattice relaxation rates of tunnelling CD3 groups
The spin lattice relaxation rates of deuterated methyl groups are calculated for threefold and sixfold potentials. It is shown that it should be possible to determine the symmetry of the potential hindering th...
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Chapter and Conference Paper
2H-NMR Stimulated Echo Study of Ultraslow Reorientational Motion in Viscous Glycerol Near its Glass Transition Temperature
2H-NMR stimulated echo experiments (spin alignment) have been performed in order to study the dynamics of the a-process in viscous glycerol near its glass transition temperature (Tg = 185K) /l/.
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Chapter and Conference Paper
Methyl Group Dynamics in α-Crystallized Toluene as Studied by 2H-Spin Lattice Relaxation
The rotational dynamics of methyl groups in molecular crystals has been under intensive study during the last decades, both experimentally and theoretically. Information concer-ning the shape and the height of...
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Chapter and Conference Paper
Nonexponential 2H-NMR Spin-Lattice Relaxation as a Signature of the Glassy State
2H nuclear spin-lattice relaxation has been investigated in several glass-forming liquids: (a) fully deuterated ortho-terphenvl, (b) selectively deuterated glycerols, namely glycerol-d3 (O-2H bon...
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Chapter and Conference Paper
Applications of “Forced Rayleigh Scattering” and “Photon Correlation Spectroscopy” for the examination of transport properties in polymer melts
The importance of optical techniques for the characterization of the dynamics in polymers has increased in the last 10 years. This was caused by the rapid development in optics and microelectronics which has m...
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Chapter
Relation of Interdiffusion and Self-Diffusion in Polymer Mixtures
From different assumptions one obtains linear relationships either between the interdiffusion coefficient and the self-diffusion coefficients or between the inverse interdiffusion coefficient and the inverse s...
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Article
Pseudo-solid echoes of proton and deuteron NMR in polyethvlene melts
The solid echo technique is applied to determining residual dipolar and quadrupolar couplings in molten polyethylene (PE) and deuterated PE, respectively. The residual coupling defined by the square root of th...
