The Pore-filling Effect of Bulk Graphite According to Viscosity of Impregnant

2021 ◽  
Vol 31 (2) ◽  
pp. 101-107
Author(s):  
Sang-Min Lee ◽  
◽  
Sang-Hye Lee ◽  
Jae-Seung Roh
Keyword(s):  
Pore Filling ◽  
Bulk Graphite

Environmental microscopy of capillary stress-induced strain behavior in ambient-pressure aerogels

1996 ◽  
Vol 54 ◽  
pp. 850-851
Author(s):  
Sudeep M. Rao ◽  
Joshua Samuel ◽  
Sai S. Prakash ◽  
C. Jeffrey Brinker
Keyword(s):  
Silica Aerogel ◽  
Ambient Pressure ◽  
Drying Shrinkage ◽  
Pore Filling ◽  
Silica Network ◽  
Strain Behavior ◽  
Partially Saturated ◽  
Capillary Stress ◽  
Wetting Liquid ◽  
Aerogel Films

Ambient pressure silica aerogel thin films have recently been prepared by exploiting reversible drying shrinkage caused by derivatization of the internal gel surface. Aerogels have porosities of upto 99.9% and due to the small size of the pores (few nanometers), large capillary stresses are produced in gels that are partially saturated with a wetting liquid. As a result of these capillary stresses, the flexible silica network undergoes strain which has been observed using environmental microscopy. This technique allows variation of the equilibrium vapor pressure and temperature, and a simultaneous monitoring of the deformation of the unconstrained film thickness. We have observed >600% deformation during the pore-filling and pore-emptying cycles. In this presentation, we discuss the unique stress-strain behavior of these films.Ref.: Sai S. Prakash, C. Jeffrey Brinker, Alan J. Hurd & Sudeep M. Rao, "Silica aerogel films prepared at ambient pressure by using surface derivatization to induce reversible drying shrinkage", Nature. Vol. 374, 30 March, 1995, 439-443.

scholarly journals Gas Porosimetry by Gas Adsorption as an Efficient Tool for the Assessment of the Shaping Effect in Commercial Zeolites

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1205
Author(s):  
Alejandro Orsikowsky-Sanchez ◽  
Christine Franke ◽  
Alexander Sachse ◽  
Eric Ferrage ◽  
Sabine Petit ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Strong Interaction ◽  
Gas Adsorption ◽  
Co2 Adsorption ◽  
Adsorption Properties ◽  
Preparation Process ◽  
Pore Filling ◽  
Irreversible Adsorption ◽  
Efficient Tool ◽  
4A Zeolite

A set of three commercial zeolites (13X, 5A, and 4A) of two distinct shapes have been characterized: (i) pure zeolite powders and (ii) extruded spherical beads composed of pure zeolite powders and an unknown amount of binder used during their preparation process. The coupling of gas porosimetry experiments using argon at 87 K and CO2 at 273 K allowed determining both the amount of the binder and its effect on adsorption properties. It was evidenced that the beads contain approximately 25 wt% of binder. Moreover, from CO2 adsorption experiments at 273 K, it could be inferred that the binder present in both 13X and 5A zeolites does not interact with the probe molecule. However, for the 4A zeolite, pore filling pressures were shifted and strong interaction with CO2 was observed leading to irreversible adsorption of the probe. These results have been compared to XRD, IR spectroscopy, and ICP-AES analysis. The effect of the binder in shaped zeolite bodies can thus have a crucial impact on applications in adsorption and catalysis.

Sorption of phenols on hexadecyltrimethylammonium- modified bentonite: Application of Polanyi−Manes potential theory

2020 ◽  
pp. 0958305X2097728
Author(s):  
Jiyeon Choi ◽  
Dong-Ik Slong ◽  
Won Sik Shin
Keyword(s):  
Molar Volume ◽  
Potential Theory ◽  
Characteristic Curve ◽  
Chemical Compositions ◽  
Pore Filling ◽  
Sorption Data ◽  
Similar Chemical ◽  
Competitive Model ◽  
Sorption Potential ◽  
Sorption Systems

This study investigated the sorption of phenol and 4-chlorophenol (4-CP) on natural bentonite modified with hexadecyltrimethylammonium (HDTMA) cation. The Freundlich, Langmuir, Dubinin−Radushkevich (DR), Sips, and Polanyi−Dubinin−Manes (PDM) models fitted the sorption data well (R2 > 0.92). The Freundlich coefficient and the maximum sorbed amount of the Langmuir and PDM models of 4-CP were higher than phenol because of higher hydrophobicity (log Kow = 2.39 for 4-CP and 1.46 for phenol). The PDM model that includes solubility and molar volume was highly useful in predicting the sorption of phenols having widely different hydrophobicity and solubility. The characteristic curves, the plot of sorbed volume ( qv) versus the sorption potential per molar volume ( ε/ Vm) of 4-CP and phenol were distinctly different although they have similar chemical compositions. The selectivity of 4-CP (3.72) was higher than that of phenol (0.27) in binary sorption systems. The sorbed volume ( qv) in the binary sorption was remarkably reduced and the characteristic curve had wider distribution owing to competition in pore-filling. The sorption behaviors were elucidated by partitioning and pore-filling mechanisms. Among the tested binary sorption models, the modified Langmuir competitive model was the best in the prediction of the binary sorption (R2 > 0.98).

Hybrid Polymer−Silicon Proton Conducting Membranes via a Pore-Filling Surface-Initiated Polymerization Approach

2009 ◽  
Vol 2 (1) ◽  
pp. 279-287 ◽  
Author(s):  
Basit Yameen ◽  
Anke Kaltbeitzel ◽  
Gunnar Glasser ◽  
Andreas Langner ◽  
Frank Müller ◽  
...  
Keyword(s):  
Hybrid Polymer ◽  
Pore Filling ◽  
Proton Conducting ◽  
Surface Initiated Polymerization ◽  
Conducting Membranes

scholarly journals Bimodal Porous Silica Prepared by Pore-filling of Silica Sol

2003 ◽  
Vol 46 (5) ◽  
pp. 335-338 ◽  
Author(s):  
Yi ZHANG ◽  
Yoshiharu YONEYAMA ◽  
Noritatsu TSUBAKI
Keyword(s):  
Porous Silica ◽  
Silica Sol ◽  
Pore Filling

Effect of Sorbent Physical Structure—Pore Size Distribution and Surface Morphology—on the Limestone Capability for Sulfation

2008 ◽  
Author(s):  
Paula M. Crnkovic ◽  
Ivonete A´vila ◽  
Fernando E. Milioli ◽  
Josmar D. Pagliuso
Keyword(s):  
Morphological Analysis ◽  
Mercury Porosimetry ◽  
Strong Dependence ◽  
Sulfur Removal ◽  
Physical Structure ◽  
Efficient Technology ◽  
Pore Filling ◽  
Air Atmosphere ◽  
Bet Analysis ◽  
Low Efficiency

Sulfur oxides are present in the gases from burning coals and these pollutants are harmful to the environment. Sulfur removal in the fluidized bed reactor applying limestones is an efficient technology. During sulfation, the formation of CaSO4 leads to the partial or complete blockade of the particle interior, resulting in a low efficiency of the use of limestones. As the desulphurization capacities of the sorbents are strongly affected by thermal condition, this paper focuses on the study of the development of the particles’ physical structure before and during sulfation reaction. The experiments were performed for two Brazilian limestones, a calcite and a dolomite. The particles were well characterized by BET analysis and mercury porosimetry and the behavior of the sorbents was observed through thermogravimetry analysis (TGA). The morphological analysis of the surface of both raw calcite and dolomite particles indicated that dolomite was a less compact sorbent. However, after calcination and sulfation, the change in pore and voids distributions showed that for dolomite both swelling and partial pore filling could take place, whereas for calcite the spaces between particles were maintained constant, possibly owing to a less intense swelling. In 30 min of reaction under air atmosphere TGA measurements provided conversions of 0.40 ±0.061 for the calcite, and 0.55 ±0.089 for the dolomite. The results showed strong dependence on meso and macropores region with high conversion of the sorbents. The reactivity differences between calcite and dolomite can also be explained based on the swelling of the particles.

Mesoporous Nitrides through Nano-Hard Templating Techniques

2007 ◽  
Vol 119 ◽  
pp. 291-294
Author(s):  
Ajayan Vinu ◽  
Srinivasan Anandan ◽  
Narasimhan Gokularkrishnan ◽  
Pavuluri Srinivasu ◽  
Toshiyuki Mori ◽  
...  
Keyword(s):  
Mesoporous Carbon ◽  
Carbon Nitride ◽  
Pore Filling ◽  
Ft Ir ◽  
Textural Parameters ◽  
Catalytic Supports ◽  
Boron Carbon Nitride ◽  
Mesoporous Carbon Nitride ◽  
Carbon Nitride Materials ◽  
Boron Carbon

Mesoporous carbon nitride materials have been synthesized using SBA-15 by pore filling technique whereas mesoporous boron nitride and boron carbon nitride have been prepared by elemental substitution technique using mesoporous carbon as template. The obtained materials have been unambiguously characterized by sophisticated techniques such as XRD, HRTEM, EELS, XPS, FT-IR and N2 adsorption. The textural parameters of the materials are quite higher as compared to the respective nonporous nitrides. These materials could offer great potential for the applications, such as catalytic supports, gas storage, biomolecule adsorption and drug delivery.

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