The Experts below are selected from a list of 186 Experts worldwide ranked by ideXlab platform
K.c. Chao - One of the best experts on this subject based on the ideXlab platform.
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Polymer chain-of-rotators equation of state
Industrial & Engineering Chemistry Research, 1996Co-Authors: R. Sy-siong-kiao, Jonathan M Caruthers, K.c. ChaoAbstract:An equation of state has been developed from the rotational partition function to describe the Polymer Molecule as a chain of rotators. The equation of state expresses the repulsion of the rotational modes of motion balanced by the attraction of the molecular segments as the molecular processes that determine the thermodynamic behavior of Polymer melts. The equation of state accurately describes, generally within 0.1% of the specific volume, the pressure−volume−temperature behavior for Polymer melts for which extensive data are available over a substantial temperature range at pressures up to 200 MPa. Four equation of state parameters are required to characterize a Polymer, and the parameter values are reported for 26 Polymers. Correlations are developed for the parameters with the molecular structure of the repeating segment of the Polymer Molecule. Using the correlations, the equation of state makes possible the estimation of volumetric and thermodynamic properties of Polymers from knowledge of their ch...
Vassili Pastushenko - One of the best experts on this subject based on the ideXlab platform.
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Steady-state gel electrophoresis of long Polymer Molecules: a theoretical study.
European biophysics journal : EBJ, 2000Co-Authors: Werner Baumgartner, Vassili PastushenkoAbstract:The velocity of long Polymer Molecules in a gel and the liquid flow profile in the vicinity of a Molecule's surface were studied theoretically by combining the Navier-Stokes equation with the Poisson-Boltzmann equation. The electrophoretic mobility has been calculated in dependence of the ionic strength of the electrolyte solution, its viscosity, the gels' volume friction coefficient, the surface charge and the radius of the Polymer Molecule. The results are presented in a non-dimensional form and depend on two dimensionless parameters only. The first parameter is the radius of the Polymer Molecule in units of the Debye length. The second is a parameter comprising the electrolyte's viscosity and the gel density. Thus, by similarity theory, the results apply to any given experimental arrangement.
Chenyu Wei - One of the best experts on this subject based on the ideXlab platform.
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Radius and chirality dependent conformation of Polymer Molecule at nanotube interface.
Nano letters, 2006Co-Authors: Chenyu WeiAbstract:Temperature-dependent conformations of linear Polymer Molecules adsorbed at carbon nanotube (CNT) interfaces are investigated through Molecule dynamics simulations. Model polyethylene (PE) Molecules are shown to have selective conformations on the CNT surface, controlled by atomic structures of the CNT lattice and geometric coiling energy. PE Molecules form entropy driven assembly domains, and their preferred wrapping angles around large radius CNT (40, 40) reflect the Molecule configurations with energy minimums on a graphite plane. While PE Molecules prefer 0 ° wrapping on small radius armchair CNT (5, 5) predominantly at low temperatures, their configurations are shifted to larger wrapping angle ones on a similar radius zigzag CNT (10, 0). A nematic transformation around 280 K is identified through the Landau-de Gennes theory, with Molecule aligning along tube axis in extended conformations.
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Radius and chirality dependent conformation of Polymer Molecule at nanotube interface
Nano letters, 2006Co-Authors: Chenyu WeiAbstract:Temperature dependent conformations of linear Polymer Molecules adsorbed at carbon nanotube (CNT) interfaces are investigated through Molecule dynamics simulations. Model polyethylene (PE) Molecules are shown to have selective conformations on CNT surface, controlled by atomic structures of CNT lattice and geometric coiling energy. PE Molecules form entropy driven assembly domains, and their preferred wrapping angles around large radius CNT (40, 40) reflect the Molecule configurations with energy minimums on a graphite plane. While PE Molecules prefer wrapping on small radius armchair CNT (5, 5) predominantly at low temperatures, their configurations are shifted to larger wrapping angle ones on a similar radius zigzag CNT (10, 0). A nematic transformation around 280 K is identified through Landau-deGennes theory, with Molecule aligning along tube axis in extended conformations
R. Sy-siong-kiao - One of the best experts on this subject based on the ideXlab platform.
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Polymer chain-of-rotators equation of state
Industrial & Engineering Chemistry Research, 1996Co-Authors: R. Sy-siong-kiao, Jonathan M Caruthers, K.c. ChaoAbstract:An equation of state has been developed from the rotational partition function to describe the Polymer Molecule as a chain of rotators. The equation of state expresses the repulsion of the rotational modes of motion balanced by the attraction of the molecular segments as the molecular processes that determine the thermodynamic behavior of Polymer melts. The equation of state accurately describes, generally within 0.1% of the specific volume, the pressure−volume−temperature behavior for Polymer melts for which extensive data are available over a substantial temperature range at pressures up to 200 MPa. Four equation of state parameters are required to characterize a Polymer, and the parameter values are reported for 26 Polymers. Correlations are developed for the parameters with the molecular structure of the repeating segment of the Polymer Molecule. Using the correlations, the equation of state makes possible the estimation of volumetric and thermodynamic properties of Polymers from knowledge of their ch...
H Jürgen Kreuzer - One of the best experts on this subject based on the ideXlab platform.
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adsorption forces on a single Polymer Molecule in contact with a solid surface
EPL, 2005Co-Authors: Felix Hanke, Leonard Livadaru, H Jürgen KreuzerAbstract:A statistical mechanical model is presented to explain recent atomic force microscope (AFM) measurements on the equilibrium forces on a Polymer chain adsorbed on a surface with one end attached to the AFM tip. We explore the dependence of this adsorption force on the depth and range of the surface potential and the characteristics of the Polymer chain. We show that the force distribution is likely due to energetic surface inhomogeneities. The effect of thermodynamic force fluctuations is also discussed.