scholarly journals The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems

2015 ◽  
Vol 1737 ◽  
Author(s):  
Cristiano F. Woellner ◽  
Leonardo D. Machado ◽  
Pedro A. S. Autreto ◽  
José A. Freire ◽  
Douglas S. Galvão
Keyword(s):  
Charge Transport ◽  
Master Equation ◽  
Carrier Mobility ◽  
Three Dimensional ◽  
Domain Size ◽  
Threshold Field ◽  
Phase System ◽  
Two Phase ◽  
Donor Acceptor ◽  
Pauli Master Equation

ABSTRACTIn this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous-crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.

scholarly journals Unraveling the Effect of Defects, Domain Size, and Chemical Doping on Photophysics and Charge Transport in Covalent Organic Frameworks

2021 ◽  
Author(s):  
Raja Ghosh ◽  
Francesco Paesani
Keyword(s):  
Charge Transport ◽  
Three Dimensional ◽  
Domain Size ◽  
Quantitative Agreement ◽  
Conclusive Evidence ◽  
Chemical Doping ◽  
Covalent Organic Frameworks ◽  
Systematic Analysis ◽  
Major Interest ◽  
Coherence Lengths

We present a novel theoretical approach to understanding the effect of electronic defects, domain size, and chemical dopants on the infrared spectral line shape and three-dimensional charge transport of positively charged polarons (“holes”) in doped (and undoped) Covalent Organic Frameworks (COFs). The simulated spectra are in excellent agreement with very recent measurements conducted on Iodine doped COF films. Through a detailed systematic analysis, we can also determine the polaron coherence lengths both along the 2D COF plane (intraframework) and through the molecular columns (interframework). The coherence lengths are important quantities in determining the anisotropic charge mobilities and conductivities in such films and are therefore of major interest in understanding the operation of organic electronic devices such as transistors and solar cells. By obtaining the first quantitative agreement with iodine doped TANG-COF, we identify well defined spectral signatures that provides conclusive evidence on why doped COFS have so far shown lower bulk conductivity compared to doped polythiophenes.

An Efficient CFD Model for Air/Particle Saltating Flows

2002 ◽  
Author(s):  
S. Ji ◽  
A. G. Gerber ◽  
A. C. M. Sousa
Keyword(s):  
Particle Concentration ◽  
Particle Surface ◽  
Three Dimensional ◽  
Phase System ◽  
Cfd Model ◽  
Computationally Efficient ◽  
Dynamics Model ◽  
Three Dimensional Flow ◽  
Two Phase ◽  
Wide Range

The study reports on the development of a computational-fluid-dynamics model is presented suitable for computationally efficient evaluation of particle transport along loose surfaces. These surfaces can be described within the context of an interaction with a two-phase air/particle mixture in a state of combined suspension and saltation. The results suggest an approach for approximating the two-phase system with coupling to a moving surface, along with the inclusion of impact and entrainment fluxes at the surface that is generally extendable to a wide range of particle/surface conditions. The model results are compared to available experimental data on particle concentration profiles along saltating surfaces, and applied to geometry involving complex three-dimensional flow to show the generality of the approach.

The Distribution of Water in the Cytoplasm

1982 ◽  
Vol 40 ◽  
pp. 4-7 ◽  
Author(s):  
K.R. Porter ◽  
D.P. Boggs ◽  
K.L. Anderson
Keyword(s):  
Cultured Cells ◽  
Three Dimensional ◽  
Phase System ◽  
Two Phase ◽  
Cytoplasmic Matrix ◽  
Rich Phase ◽  
Soluble Phase ◽  
Metabolic Reactions ◽  
20 Nm ◽  
Protein Rich

It has become apparent in recent years that the cytoplasmic matrix (cytomatrix) is structured. If the evidence available for this is correctly interpreted, we should put aside the concept that the majority of the enzymes which catalyze metabolic reactions are in solution in a soluble phase of the cytoplasm, also called the cytosol. This evidence, derived in large part from high voltage micrographs of whole cultured cells, says that the cytomatrix is a three-dimensional mesliwork of fine strands measuring 5-20 nm in diameter and 50-200 nm in length. By its existence, the microtrabecular lattice transforms the cytosol into a two-phase system, one protein-rich and the other water-rich. It is the purpose of this paper to report a few observations on the latter of these two, i.e. the water-rich phase.

Intersect distributions of a `dead leaves' model with spherical primary grains

2005 ◽  
Vol 38 (3) ◽  
pp. 520-527 ◽  
Author(s):  
Wilfried Gille
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Length Distribution ◽  
Hard Core ◽  
Spherical Particles ◽  
Characteristic Functions ◽  
Phase System ◽  
Two Phase ◽  
Linear Integration ◽  
Dead Leaves Model

This article analyses a tightly packed random two-phase system possessing spherical particles having the volume fraction of 1/8. For a three-dimensional hard-core `dead leaves' model of spheres of constant diameter, the chord length distribution density of typical chords m i of the connected phase (outside the hard particles) is investigated. The calculation starts from the second derivative of the small-angle scattering correlation function of the model and applies characteristic functions. The result fulfills Rosiwal's linear integration principle.

A map of membrane populations isolated from rat exorbital gland

1984 ◽  
Vol 247 (6) ◽  
pp. G651-G661 ◽  
Author(s):  
A. K. Mircheff ◽  
C. C. Lu
Keyword(s):  
Endoplasmic Reticulum ◽  
Three Dimensional ◽  
Sedimentation Coefficient ◽  
Subcellular Fractionation ◽  
Phase System ◽  
Two Phase ◽  
Aqueous Polymer ◽  
Enzymatic Markers ◽  
Apical Membranes ◽  
Two Populations

We combined separation procedures based on three independent physical properties, sedimentation coefficient, density, and partitioning in an aqueous polymer two-phase system, to generate a three-dimensional subcellular fractionation of rat exorbital lacrimal gland. The distributions of protein and five enzymatic markers define a total of 13 physically and biochemically distinct membrane populations. These include epithelial cell apical membranes, purified 330-fold with respect to the initial homogenate; basal-lateral membranes, purified 80-fold; mitochondria, purified 19-fold; anda major endoplasmic reticulum population, purified 22-fold. Also apparent is a major Golgi population, which is extensively overlapped by other membrane populations; two populations that can be visualized as forming transitions between the endoplasmic reticulum and Golgi membranes; and several populations with unknown subcellular origins. Most of the markershave complex distributions among the isolated membrane populations; this complexity is consistent with current concepts of the synthesis and recycling of membrane constituents and the regulation of cytosolic electrolyte activities.

scholarly journals Unraveling the Effect of Defects, Domain Size, and Chemical Doping on Photophysics and Charge Transport in Covalent Organic Frameworks

2021 ◽  
Author(s):  
Raja Ghosh ◽  
Francesco Paesani
Keyword(s):  
Charge Transport ◽  
Three Dimensional ◽  
Domain Size ◽  
Quantitative Agreement ◽  
Conclusive Evidence ◽  
Chemical Doping ◽  
Covalent Organic Frameworks ◽  
Systematic Analysis ◽  
Major Interest ◽  
Coherence Lengths

We present a novel theoretical approach to understanding the effect of electronic defects, domain size, and chemical dopants on the infrared spectral line shape and three-dimensional charge transport of positively charged polarons (“holes”) in doped (and undoped) Covalent Organic Frameworks (COFs). The simulated spectra are in excellent agreement with very recent measurements conducted on Iodine doped COF films. Through a detailed systematic analysis, we can also determine the polaron coherence lengths both along the 2D COF plane (intraframework) and through the molecular columns (interframework). The coherence lengths are important quantities in determining the anisotropic charge mobilities and conductivities in such films and are therefore of major interest in understanding the operation of organic electronic devices such as transistors and solar cells. By obtaining the first quantitative agreement with iodine doped TANG-COF, we identify well defined spectral signatures that provides conclusive evidence on why doped COFS have so far shown lower bulk conductivity compared to doped polythiophenes.

scholarly journals Preparation of Microporous Hydrogel Sponges for 3D Perfusion Culture of Mammalian Cells

2021 ◽  
Vol 333 ◽  
pp. 07004
Author(s):  
Aruto Hori ◽  
Rie Utoh ◽  
Masumi Yamada ◽  
Minoru Seki
Keyword(s):  
Cell Culture ◽  
Mammalian Cells ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Perfusion Culture ◽  
Phase System ◽  
Two Phase ◽  
Produce Cell ◽  
Hydrogel Matrix

Three-dimensional (3D) perfusable organ models, primarily composed of liver cells, are expected as an efficient tool for in vitro cell-based drug screening and development. Various types of hydrogel-based 3D cell culture systems have been developed, but the lack in proper techniques to form vasculature networks in the hydrogel matrices results in inefficient supply of oxygen and nutrition to the cells. Here we propose a facile strategy to creating a perfusable hydrogel-based liver cell culture system. We utilized a bicontinuous dispersion of an aqueous two-phase system, which was composed of polyethylene glycol (PEG)-rich and gelatin methacrylate (GelMA)-rich phases, to produce cell-encapsulating microporous GelMA-based hydrogels. We successfully encapsulated HepG2 cells in the hydrogel matrix with a high cell viability, and confirmed that the spongious hydrogel was superior to homogeneous hydrogels for 3D cell culture. We performed perfusion culture for the cells encapsulated in the hydrogel sponge, to verify the usability and versatility of the presented hydrogel material for perfusion culture. The presented approach would be useful as a unique tool for developing organs-on-a-chip systems.

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