scholarly journals Features of determining the parameters of the porous structure of ceramic materials

2019 ◽  
Vol 1 (5) ◽  
pp. 117-121
Author(s):  
Yu. N. Kryuchkov
Keyword(s):  
Porous Structure ◽  
Porous Materials ◽  
Pore Volume ◽  
Mercury Porosimetry ◽  
Ceramic Materials ◽  
Large Error ◽  
Volume Distribution ◽  
Capillary Effects ◽  
Percolation Effect ◽  
Liquid Displacement

The methods for determining the pore volume distribution by the size of porous materials are analyzed and it is shown that the most rigorous are methods in which capillary effects do not appear. It is shown that mercury porosimetry and the method of liquid displacement by gas have a large error in the region of large pores. This is due to the percolation effect. It is proved that determining the distribution of pore volume from measurements of air flow gives too distorted results, so its use is not advisable.

scholarly journals The application of macroporous copolymers in the sorption of heavy and precious metals from aqueous solutions

2006 ◽  
Vol 60 (11-12) ◽  
pp. 306-310
Author(s):  
Aleksandra Nastasovic ◽  
Slobodan Jovanovic ◽  
Antonije Onjia ◽  
Zvjezdana Sandic ◽  
Ljiljana Malovic ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Pore Volume ◽  
Mercury Porosimetry ◽  
Precious Metals ◽  
Volume Distribution ◽  
Specific Pore Volume ◽  
Capacity Loss ◽  
Ring Opening Reaction ◽  
Static Conditions ◽  
Desorption Cycle

Macroporous crosslinked poly(GMA-co-EGDMA) was synthesized by the suspension copolymerisation and functionalized by the ring-opening reaction of the pendant epoxy groups with ethylene diamine. The porosity parameters (specific pore volume, specific surface area, and pore diameter, which corresponds to half of the pore volume) for the initial and amino-functionalized copolymer samples were calculated from the cumulative pore volume distribution curves obtained by mercury porosimetry. The selectivity, sorption capacity and sorption rate of amino-functionalized poly(GMA-co-EGDMA)-en were determined under static conditions. The sorption of Cu(ll) and Ag(l) ions on poly(GMA-co-EGDMA)-en was very rapid (ti/2 value about 1 min). Slower sorption was observed for Au(lll) ions with a ti/2 value of 6.5 minutes. The different rates of Au(lll), Cu(ll) and Ag(l) sorption could be applied for gold, copper and silver ion separation from mixed solutions. The sorption of Ni(ll) and Cu(ll) ions from galvanic solution under competitive conditions was also fast, with ti/2 values of 0.5 and 2 min, respectively. However, Zn(ll) sorption was considerably slower (a ti/2 of 10 min). Similar results were obtained for galvanic solution under dynamic conditions, i.e., the metal sorption capacities of poly(GMA-co-EGDMA)-en decreased in the order: Ni(ll) > Cu(ll) >> Zn(ll). The reusability of amino-functionalized poly(GMA-co-EGDMA) for Cu(ll) sorption was tested in four sorption/desorption cycles. Regeneration experiments were performed with 0.1 and 1 M H2SO4 showed a Cu(ll) capacity loss of 50 % in the first sorption/desorption cycle. The sorption capacity increased when additional neutralization with 0.1 and 1 M NaOH was performed after each sorption/desorption cycle.

Porous Structure and Transport Properties of a Carbonized Phenolic Resin

1995 ◽  
Vol 60 (2) ◽  
pp. 172-187 ◽  
Author(s):  
Pavel Fott ◽  
František Kolář ◽  
Zuzana Weishauptová
Keyword(s):  
Porous Structure ◽  
Transport Properties ◽  
Phenolic Resin ◽  
Arrhenius Equation ◽  
Mercury Porosimetry ◽  
Micropore Volume ◽  
Microporous Structure ◽  
Wetting And Drying ◽  
Phenolic Resins ◽  
Kinetics Of

On carbonizing phenolic resins, the development of porous structure takes place which influences the transport properties of carbonized materials. To give a true picture of this effect, specimens in the shape of plates were prepared and carbonized at various temperatures. The carbonizates obtained were studied by adsorption methods, electron microscopy, and mercury porosimetry. Diffusivities were evaluated in terms of measuring the kinetics of wetting and drying. It was found out that the porous structure of specimens in different stages of carbonization is formed mostly by micropores whose volumes were within 0.06 to 0.22 cm3/g. The maximum micropore volume is reached at the temperature of 750 °C. The dependence of diffusivity on the carbonization temperature is nearly constant at first, begins to increase in the vicinity of 400 °C, and at 600 °C attains its maximum. The experimental results reached are in agreement with the conception of the development and gradual closing of the microporous structure in the course of carbonization. The dependence of diffusivity on temperature can be expressed by the Arrhenius equation. In this connection, two possible models of mass transport were discussed.

Hard Materials with Tunable Porosity

MRS Bulletin ◽  
2009 ◽  
Vol 34 (8) ◽  
pp. 561-568 ◽  
Author(s):  
Jonah Erlebacher ◽  
Ram Seshadri
Keyword(s):  
Porous Materials ◽  
Self Assembly ◽  
Porous Metal ◽  
Ceramic Materials ◽  
Equilibrium Temperature ◽  
Length Scale ◽  
Porous Metals ◽  
Hard Materials ◽  
Mesoporous Zeolites ◽  
Pattern Forming

AbstractPorous metals and ceramic materials are of critical importance in catalysis, sensing, and adsorption technologies and exhibit unusual mechanical, magnetic, electrical, and optical properties compared to nonporous bulk materials. Materials with nanoscale porosity often are formed through molecular self-assembly processes that lock in a particular length scale; consider, for instance, the assembly of crystalline mesoporous zeolites with a pore size of 2–50 nm or the evolution of structural domains in block copolymers. Of recent interest has been the identification of general kinetic pattern-forming principles that underlie the formation of mesoporous materials without a locked- in length scale. When materials are kinetically locked out of thermodynamic equilibrium, temperature or chemistry can be used as a “knob” to tune their microstructure and properties. In this issue of the MRS Bulletin, we explore new porous metal and ceramic materials, which we collectively refer to as “hard” materials, formed by pattern-forming instabilities, either in the bulk or at interfaces, and discuss how such nonequilibrium processing can be used to tune porosity and properties. The focus on hard materials here involves thermal, chemical, and electrochemical processing usually not compatible with soft (for example, polymeric) porous materials and generally adds to the rich variety of routes to fabricate porous materials.

scholarly journals Investigation of the Porosity of Certain Iraqi Clay Deposits by Mercury Porosimeter

2009 ◽  
Vol 6 (1) ◽  
pp. 163-172
Author(s):  
Baghdad Science Journal
Keyword(s):  
Pore Volume ◽  
Pore Diameter ◽  
Mercury Intrusion Porosimetry ◽  
Narrow Range ◽  
Volume Distribution ◽  
Natural Clay ◽  
Mercury Intrusion ◽  
Clay Deposits ◽  
Pore Area ◽  
Mercury Porosimeter

Pore volume, pore diameter, and pore volume distribution of three of Iraqi natural clay deposites were measured using mercury intrusion porosimetry .The clays are white kaolin, colored kaolin, and bentonite .The results showed that the variation of the pore area of the clay deposites followed the following order :- Coloured Kaolin > White Kaolin > Bentonite While the pore volume may be arranged as in the following sequence:- White Kaolin > Coloured Kaolin >Bentonite Also , Bentonite exhibits the narrow range pore size distribution than the white and coloured kaolin.

scholarly journals Dielectric Phase Transition Behaviour Study of Dry Route Derived (BA0.5 SN0.5) TIO3 Ceramics

2019 ◽  
Vol 40 ◽  
pp. 73-77
Author(s):  
Bhojraj Bhandari ◽  
Bhadra Prasad Pokheral
Keyword(s):  
Phase Transition ◽  
Barium Titanate ◽  
Content Volume ◽  
Ceramic Materials ◽  
Hydraulic Press ◽  
Binary Solid Solution ◽  
Sensor Material ◽  
Wide Range ◽  
Free Environment ◽  
Liquid Displacement

Ceramic materials display a wide range of properties that facilitate their use in many different product areas. Currently, there has been keen interest in the field of ceramic materials due to their excellent mechanical and physical properties. Barium Stannate Titanate (BST) is a binary solid solution system composed of ferroelectric Barium titanate and non-ferroelectric barium titanate. In this study, the phase transition behavior of (Ba1-xSnx)TiO3 (x = 0.5) (BST) ceramics  was obtained by the dry-route method. The previous studies were based on Sn 2+ on the Ti site with varying values of x. The powders after calcination are compacted in the form of pellets using a hydraulic press at an optimized load above 70KN. The experimental density of our sample measured by liquid displacement method with glycerin was lower than theoretical density, giving the shape is highly dense with low porosity. The structure shows that on increasing the Sn2+ content volume decreases due to the size of Sn2+, which is smaller than that of Ba2+, in comparison to BaTiO3. As the demand of lead-free environment-friendly sensor is increasing, thus obtained BST has great applications as a sensor material in modern electronic devices.

Preparation of a graphene-based composite aerogel and the effects of carbon nanotubes on preserving the porous structure of the aerogel and improving its capacitor performance

2015 ◽  
Vol 3 (25) ◽  
pp. 13445-13452 ◽  
Author(s):  
Zhihua Ma ◽  
Xiaowei Zhao ◽  
Chunhong Gong ◽  
Jingwei Zhang ◽  
Jiwei Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Porous Structure ◽  
Pore Volume ◽  
Composite Aerogel ◽  
3D Graphene ◽  
Volume Conductivity ◽  
Capacitor Performance

Carbon nanotube supported 3D graphene-based composite aerogel was prepared, which exhibited high pore volume, conductivity, and great capacitor performance.

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