Structure and rheological behavior of highly charged colloidal particles in a cylindrical pore I. Effect of pore size

2003 ◽  
Vol 267 (1) ◽  
pp. 233-242
Author(s):  
Miguel A. Valdez ◽  
Rogelio Gámez-Corrales
Keyword(s):  
Pore Size ◽  
Rheological Behavior ◽  
Colloidal Particles ◽  
Cylindrical Pore

DYNAMICS OF SIMPLE FLUIDS CONFINED IN CYLINDRICAL PORE: EFFECT OF PORE SIZE

2005 ◽  
Vol 04 (01) ◽  
pp. 305-315 ◽  
Author(s):  
HYUNGJUN KIM ◽  
CHUL HEE CHO ◽  
EOK KYUN LEE
Keyword(s):  
Pore Size ◽  
Particle Diameter ◽  
Simulation Method ◽  
The Self ◽  
Dynamics Simulation ◽  
Axial Component ◽  
Cylindrical Pore ◽  
Self Diffusion ◽  
Wide Range ◽  
Wall Interaction

We study the thermodynamic and dynamical properties of Weeks–Chandler–Anderson (WCA) fluids confined in a cylindrical pore by means of a canonical molecular dynamics simulation method. The pore model is an infinitely long cylinder consisted of a thermal wall and mimics a typical carbon nanotube. The thermodynamic properties are obtained for relatively high density fluids over a wide range of pore diameters at a given temperature. The size dependence of the self-diffusion coefficients in the cylindrical pore is also investigated. It is found that, as the pore diameter decreases, the potential energy and axial component of the pressure exhibit a sharp rise and the self-diffusion coefficient decreases. The observed behaviors can be understood in terms of the geometrical confinement and attenuation of transport induced by dispersive fluid-wall interaction. In addition, anomalous diffusion is observed at the pore size corresponding to twice the particle diameter.

Low Reynolds Number Interactions between Colloidal Particles near the Entrance to a Cylindrical Pore

2000 ◽  
Vol 229 (2) ◽  
pp. 311-322 ◽  
Author(s):  
Venkatachalam Ramachandran ◽  
Ramachandran Venkatesan ◽  
Grétar Tryggvason ◽  
H. Scott Fogler
Keyword(s):  
Reynolds Number ◽  
Colloidal Particles ◽  
Low Reynolds Number ◽  
Cylindrical Pore ◽  
Low Reynolds

scholarly journals Synthesis and characterization of porous silica and polyaniline-porous silica composite materials with high surface area

2014 ◽  
Vol 49 (1) ◽  
pp. 1-8
Author(s):  
US Akhtar ◽  
MK Hossain ◽  
MS Miran ◽  
MYA Mollah
Keyword(s):  
Electron Microscopy ◽  
Pore Size ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Porous Silica ◽  
Nitrogen Adsorption ◽  
High Specific Surface Area ◽  
Molar Ratio ◽  
Cylindrical Pore

Porous silica materials were synthesized from tetraethyl orthosilicate (TEOS) using Pluronic P123 (non-ionic triblock copolymer, EO20PO70O20) as template under acidic conditions which was then used to prepare polyaniline (PAni) and porous silica composites (PAnisilica) at a fixed molar ratio. These materials were characterized by nitrogen adsorption-desorption isotherm measured by Barrett-Joyner- Halenda (BJH) method and pore size distribution from desorption branch and surface area measured by the Brunauer-Emmett-Teller (BET) method, scanning electron microscopy (SEM), transmission electron microscopy (TEM), TEM-energy dispersive X-ray (EDX) and Fourier transform infrared (FT-IR) spectroscopy. The composite maintains its structure even after the polymerization and the polymer is dispersed on the inorganic matrix. The rod-like porous silica was about 1?m to 1.5 ?m long and on an average the diameter was in the range of 300- 500 nm. The SEM and TEM images show well ordered 2d hexagonal pore, high specific surface area (850 m2g-1) and uniform pore size of ca. 6.5 nm in diameter. After incorporation of PAni inside the silica pore, framework of porous silica did not collapse and the surface area of the composite was as high as 434 m2g-1 which was 5.5 time higher than our previous report of 78.3 m2g-1. Due to shrinkage of the framework during the incorporation of aniline inside the silica, the pore diameter slightly increase to 7.5 nm but still showing Type IV isotherm and typical hysteresis loop H1 implying a uniform cylindrical pore geometry. DOI: http://dx.doi.org/10.3329/bjsir.v49i1.18847 Bangladesh J. Sci. Ind. Res. 49(1), 1-8, 2014

scholarly journals Charging dynamics of electrical double layers inside a cylindrical pore: predicting the effects of arbitrary pore size

Soft Matter ◽  
2022 ◽  
Author(s):  
Filipe Henrique ◽  
Pawel J. Zuk ◽  
Ankur Gupta
Keyword(s):  
Transmission Line ◽  
Pore Size ◽  
Debye Length ◽  
Double Layers ◽  
Cylindrical Pore ◽  
Electrical Double Layers ◽  
Charging Dynamics

The effect of arbitrary pore size and Debye length on the charging dynamics of electrical double layers inside a cylindrical pore is computed, and its impact on capacitance, charging timescale, and transmission line circuit is highlighted.

scholarly journals Cooperative CO2 adsorption promotes high CO2 adsorption density over wide optimal nanopore range

2017 ◽  
Vol 36 (1-2) ◽  
pp. 625-639 ◽  
Author(s):  
Lei Chen ◽  
Takumi Watanabe ◽  
Hirofumi Kanoh ◽  
Kenji Hata ◽  
Tomonori Ohba
Keyword(s):  
Porous Media ◽  
Specific Surface ◽  
Pore Size ◽  
Co2 Adsorption ◽  
High Capacity ◽  
Potential Wells ◽  
Cylindrical Pore ◽  
Cooperative Adsorption ◽  
Wide Range ◽  
Adsorption Density

Separation of CO2 based on adsorption, absorption, and membrane techniques is a crucial technology necessary to address current global warming issues. Porous media are essential for all these approaches and understanding the nature of the porous structure is important for achieving highly efficient CO2 adsorption. Porous carbon is considered to be a suitable porous media for investigating the fundamental mechanisms of CO2 adsorption, because of its simple morphology and its availability in a wide range of well-defined pore sizes. In this study, we investigated the dependence of CO2 adsorption on pore structures such as pore size, volume, and specific surface area. We also studied slit-shaped and cylindrical pore morphologies based on activated carbon fibers of 0.6–1.7 nm and carbon nanotubes of 1–5 nm, respectively, with relatively uniform structures. Porous media with larger specific surface areas gave higher CO2 adsorption densities than those of media having larger pore volumes. Narrower pores gave higher adsorption densities because of deep adsorption potential wells. However, at a higher pressure CO2 adsorption densities increased again in nanopores including micropores and small mesopores. The optimal pore size ranges of CO2 adsorption in the slit-shaped and cylindrical carbon pores were 0.4–1.2 and 1.0–2.0 nm, respectively, although a high adsorption density was only expected for the narrow carbon nanopores from adsorption potentials. The wider nanopore ranges than expected nanopore ranges are reasonable when considering intermolecular interactions in addition to CO2–carbon pore interactions. Therefore, cooperative adsorption among CO2 in relatively narrow nanopores can allow for high density and high capacity adsorption.

Preparation and Properties of Porous Alumina Ceramics with Oriented Pores

2006 ◽  
Vol 317-318 ◽  
pp. 689-692 ◽  
Author(s):  
Toshihiro Isobe ◽  
Yoshikazu Kameshima ◽  
Akira Nakajima ◽  
Kiyoshi Okada
Keyword(s):  
Pore Size ◽  
Porous Alumina ◽  
Alumina Powder ◽  
Alumina Ceramics ◽  
Nylon 66 ◽  
Cylindrical Pore ◽  
High Degree ◽  
Very High ◽  
Extrusion Method ◽  
Good Agreement

Porous alumina ceramics with unidirectionally oriented pores were prepared by an extrusion method. Pastes for extrusion were prepared by mixing alumina powder with nylon 66 fibers (av. 19 μm in diameter), together with dispersants and binders. The resulting pastes were extruded, dried at room temperature, freed from the binder at 600 °C and fired at 1500 °C for 2 h. The pore size distribution of the samples showed pores of 16 μm diameter, in good agreement with the original nylon 66 fibers. The pore size observed from SEM photographs of the sintered body was 16 μm corresponding to the burnt-out nylon 66 fibers. A very high degree of cylindrical pore orientation was seen in the SEM micrographs of the samples. The orientation increases with decreasing fiber loading.

scholarly journals A Multivariate Statistical Analyses of Membrane Performance in the Clarification of Citrus Press Liquor

2019 ◽  
Vol 3 (1) ◽  
pp. 10
Author(s):  
René Ruby-Figueroa ◽  
Monica Nardi ◽  
Giovanni Sindona ◽  
Carmela Conidi ◽  
Alfredo Cassano
Keyword(s):  
Molecular Weight ◽  
Pore Size ◽  
Bioactive Compounds ◽  
Colloidal Particles ◽  
Operating Time ◽  
Partial Least Square ◽  
Operating Conditions ◽  
Membrane Thickness ◽  
Permeate Flux ◽  
Membrane Performance

The orange press liquor is a by-product of the orange juice production containing bioactive compounds recognized for their beneficial implications in human health. The recovery of these compounds offers new opportunities for the formulation of products of interest in food, pharmaceutical and cosmetic industry. The clarification of orange press liquor by microfiltration (MF) and/or ultrafiltration (UF) processes is a valid approach to remove macromolecules, colloidal particles, and suspended solids from sugars and bioactive compounds. In this work the clarification of orange press liquor was studied by using three flat-sheet polymeric membranes: a MF membrane with a pore size of 0.2 μm and two UF membranes with nominal molecular weight cut-off (MWCO) of 150 and 200 kDa, respectively. The membrane performance, in terms of permeate flux and membrane rejection towards hesperidin and sugars, was studied according to a multivariate analyses approach. In particular, characteristics influencing the performance of the investigated membranes, such as molecular weight cut-off (MWCO), contact angle, membrane thickness, pore size distribution, as well as operating conditions, including temperature, and operating time, were analysed through the partial least square regression (PLSR). The multivariate method revealed crucial information on variables which are relevant to maximize the permeate flux and to minimize the rejection of hesperidin and sugars in the clarification of orange press liquor.

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