scholarly journals Migration of nanoparticles across a polymer-polymer interface: theory and simulation

Soft Matter ◽  
2021 ◽  
Author(s):  
Nigel Gibbions ◽  
Didier René Long ◽  
Nigel Clarke
Keyword(s):  
Theoretical Description ◽  
Thermodynamical Equilibrium ◽  
Polymer Interface ◽  
Interface Theory ◽  
Inhomogeneous Liquids

We proposed recently a theoretical description for hydrodynamic flows in inhomogeneous liquids in the vicinity of solid interfaces, consistent with current theoretical descriptions of the thermodynamical equilibrium of liquids in...

scholarly journals Molecular Excitation and Radiative Transfer: Current Results and Future Prospects

2000 ◽  
Vol 197 ◽  
pp. 81-94
Author(s):  
John H. Black
Keyword(s):  
Angular Resolution ◽  
Theoretical Models ◽  
Molecular Data ◽  
Theoretical Description ◽  
Line Profiles ◽  
Thermodynamical Equilibrium ◽  
Molecular Gases ◽  
Line Intensities ◽  
Submillimeter Wavelengths ◽  
Molecular Excitation

The spectra of dilute molecular gases in astrophysics arise in material far out of thermodynamical equilibrium (non-LTE), often in inhomogeneous atmospheres where Doppler motions from kinematical gradients and turbulence are large compared with thermal motions. Thus line intensities contain information about density and temperature as well as abundances, and line profiles probe the structure of the atmosphere. However, the theoretical description of the atmosphere can be extremely complicated and can make enormous demands for molecular data. Improvements in angular resolution and the possibility to make sensitive spectroscopic measurements at mid-infrared and submillimeter wavelengths pose new challenges for theoretical models.

Surface Modification of Poly (alkyl/Arylphosphazene) Thin Films

2000 ◽  
Vol 629 ◽  
Author(s):  
John V. St. John ◽  
Patty Wisian-Neilson
Keyword(s):  
Thin Films ◽  
Surface Modification ◽  
Chemical Resistance ◽  
Chemical Properties ◽  
Inorganic Polymers ◽  
Thin Polymer Films ◽  
Hydrophilic Interactions ◽  
Carboxylic Acid Groups ◽  
Polymer Interface ◽  
Thin Polymer

ABSTRACTPoly (methylphenylphosphazene) (PMPP) is an example of a unique class of inorganic polymers with alternating – (P=N)– backbones. Chemical modification of bulk PMPP can result in changes of physical properties such as chemical resistance, onset temperature of thermal degradation, elasticity, and flexibility. Surface modification of PMPP allows tailoring of the chemical properties at the polymer interface while maintaining the integrity of the bulk polymer. In this research, PMPP thin films were treated to form carboxylate or carboxylic acid groups at the surface. Surface modification was monitored by following changes in contact angle. The hydrophobic/hydrophilic interactions of carboxylated PMPP surfaces allow for mesoscale interactions of thin polymer films.

Analysis of shear bands in slow granular flows using a frictional Cosserat model

2000 ◽  
Vol 627 ◽  
Author(s):  
Prabhu R. Nott ◽  
K. Kesava Rao ◽  
L. Srinivasa Mohan
Keyword(s):  
Scaling Laws ◽  
Shear Bands ◽  
Shear Layers ◽  
Theoretical Description ◽  
Field Variable ◽  
Cosserat Continuum ◽  
Momentum Balance ◽  
Rigid Plastic ◽  
Independent Field ◽  
Cosserat Model

ABSTRACTThe slow flow of granular materials is often marked by the existence of narrow shear layers, adjacent to large regions that suffer little or no deformation. This behaviour, in the regime where shear stress is generated primarily by the frictional interactions between grains, has so far eluded theoretical description. In this paper, we present a rigid-plastic frictional Cosserat model that captures thin shear layers by incorporating a microscopic length scale. We treat the granular medium as a Cosserat continuum, which allows the existence of localised couple stresses and, therefore, the possibility of an asymmetric stress tensor. In addition, the local rotation is an independent field variable and is not necessarily equal to the vorticity. The angular momentum balance, which is implicitly satisfied for a classical continuum, must now be solved in conjunction with the linear momentum balances. We extend the critical state model, used in soil plasticity, for a Cosserat continuum and obtain predictions for flow in plane and cylindrical Couette devices. The velocity profile predicted by our model is in qualitative agreement with available experimental data. In addition, our model can predict scaling laws for the shear layer thickness as a function of the Couette gap, which must be verified in future experiments. Most significantly, our model can determine the velocity field in viscometric flows, which classical plasticity-based model cannot.

The Reactive Formation of Diblock Copolymer at a Polymer/Polymer Interface and its Effect on Interfacial Structure

2000 ◽  
Vol 629 ◽  
Author(s):  
Jonathan S. Schulze ◽  
Timothy P. Lodge ◽  
Christopher W. Macosko
Keyword(s):  
Molecular Weight ◽  
Interfacial Structure ◽  
Root Mean Square Roughness ◽  
Radius Of Gyration ◽  
Interfacial Region ◽  
Force Microscopy ◽  
Amino Terminal ◽  
Polymer Interface ◽  
Atomic Force ◽  
Time Required

ABSTRACTThe reaction of perdeuterated amino-terminal polystyrene (dPS-NH2) with anhydrideterminal poly(methyl methacrylate) (PMMA-anh) at a PS/PMMA interface has been observed with forward recoil spectrometry (FRES). Bilayer samples were constructed by placing thin films of PS containing ∼8.5 wt % dPS-NH2 on a PMMA-anh layer. Significant reaction was observed only after annealing the samples at 174°C for several hours, a time scale at least two orders of magnitude greater than the time required for the dPS-NH2 chains to diffuse through the bulk PS layer. The topography of the interfacial region as copolymer formed was measured using atomic force microscopy (AFM). Roughening of the PS/PMMA interface was observed to varying degrees in all annealed samples. Furthermore, the extent of this roughening was found to depend on the PS matrix molecular weight. Reaction in the samples with a high molecular weight PS matrix resulted in a root mean square roughness approximately equal to the radius of gyration Rg of the copolymer. However, approximately twice as much roughening was observed in the low molecular weight PS matrix. This study reveals how the molecular weight of one of the phases can affect the rate of reaction at a polymer/polymer interface.

Set-Theoretical Description of the System for Control of the State of Technical Information Protection

2005 ◽  
Vol 64 (3) ◽  
pp. 227-237
Author(s):  
A. V. Zhizhelev ◽  
S. V. Zhilinskii ◽  
A. V. Klyshevskii ◽  
S. A. Golovin
Keyword(s):  
Technical Information ◽  
Theoretical Description ◽  
The State ◽  
Information Protection

Theoretical description of nucleons correlations of even-even atomic nuclei

2003 ◽  
Vol 14 (0) ◽  
pp. 40-45
Author(s):  
Р. М. Плекан ◽  
В. Ю. Пойда ◽  
І. В. Хіміч
Keyword(s):  
Theoretical Description ◽  
Atomic Nuclei

The Determination of the Magnetoelectric Coupling Coefficient in Ferroelectric–Ferromagnetic Composite Based on PZT–Ferrite

2013 ◽  
Vol 58 (4) ◽  
pp. 1401-1403 ◽  
Author(s):  
J.A. Bartkowska ◽  
R. Zachariasz ◽  
D. Bochenek ◽  
J. Ilczuk
Keyword(s):  
Dielectric Permittivity ◽  
Coupling Coefficient ◽  
Mean Field ◽  
Field Approximation ◽  
Theoretical Description ◽  
Magnetoelectric Coupling ◽  
Mean Field Approximation ◽  
Dielectric Measurements ◽  
Temperature Dependences ◽  
Multiferroic Composite

Abstract In the present work, the magnetoelectric coupling coefficient, from the temperature dependences of the dielectric permittivity for the multiferroic composite was determined. The research material was ferroelectric-ferromagnetic composite on the based PZT and ferrite. We investigated the temperature dependences of the dielectric permittivity (") for the different frequency of measurement’s field. From the dielectric measurements we determined the temperature of phase transition from ferroelectric to paraelectric phase. For the theoretical description of the temperature dependence of the dielectric constant, the Hamiltonian of Alcantara, Gehring and Janssen was used. To investigate the dielectric properties of the multiferroic composite this Hamiltonian was expressed under the mean-field approximation. Based on dielectric measurements and theoretical considerations, the values of the magnetoelectric coupling coefficient were specified.

Chemical Characterization of Metal/Polymer interface

2015 ◽  
Vol 84 (8) ◽  
pp. 591-595 ◽  
Author(s):  
Yukiko IZUMI ◽  
Naoki BADEN ◽  
Kazuhiro MATSUDA
Keyword(s):  
Chemical Characterization ◽  
Polymer Interface ◽  
Metal Polymer
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