Preparation of Carbon Monoliths by a Simple Polymer Blend Technique

2014 ◽  
Vol 700 ◽  
pp. 125-131
Author(s):  
Jie Cheng ◽  
Han Min Liu ◽  
Dong Chen ◽  
Yue Hua Wen ◽  
Gao Ping Cao
Keyword(s):  
Pore Size ◽  
Polymer Blend ◽  
Pore Diameter ◽  
Polyvinyl Butyral ◽  
Carbonization Temperature ◽  
Pore Former ◽  
Average Pore ◽  
Narrow Pore Size Distribution ◽  
Stabilization Temperature ◽  
Precursor Powders

Porous carbon monoliths are prepared by carbonization of a simple polymer blend, in which phenolic resin (PF) as carbon precursor, polyvinyl butyral as pore former and activated carbon as conducting additive and contraction inhibitor are used to make polymer blend. The results show that the carbon monoliths, with a narrow pore size distribution with mean controlled diameters in the sub-micron/micron range, can be easily produced by controlling the stabilization temperature of the PF, the carbonization temperature, and particle diameters of the precursor powders. The pore size decrease as the stabilization temperature of the PF increases or the particle diameters of the precursor powders decreases. The electrical resistance of the carbon monoliths decreases as the carbonization temperature increases, but the average pore diameter and volume of the carbon monoliths are almost constant as the carbonization temperature increases.

Diffusion of Heavy Oil in SiO2 Model Catalyst and FCC Catalyst

2012 ◽  
Vol 550-553 ◽  
pp. 158-163 ◽  
Author(s):  
Zi Yuan Liu ◽  
Sheng Li Chen ◽  
Peng Dong ◽  
Xiu Jun Ge
Keyword(s):  
Diffusion Coefficient ◽  
Pore Size ◽  
Effective Diffusion Coefficient ◽  
Pore Diameter ◽  
Effective Diffusion ◽  
Model Catalyst ◽  
Average Pore ◽  
Diffusion Factor ◽  
Fcc Catalyst ◽  
Fcc Catalysts

Through the measured effective diffusion coefficients of Dagang vacuum residue supercritical fluid extraction and fractionation (SFEF) fractions in FCC catalysts and SiO2model catalysts, the relation between pore size of catalyst and effective diffusion coefficient was researched and the restricted diffusion factor was calculated. The restricted diffusion factor in FCC catalysts is less than 1 and it is 1~2 times larger in catalyst with polystyrene (PS) template than in conventional FCC catalyst without template, indicating that the diffusion of SFEF fractions in the two FCC catalysts is restricted by the pore. When the average molecular diameter is less than 1.8 nm, the diffusion of SFEF fractions in SiO2model catalyst which average pore diameter larger than 5.6 nm is unrestricted. The diffusion is restricted in the catalyst pores of less than 8 nm for SFEF fractions which diameter more than 1.8 nm. The tortuosity factor of SiO2model catalyst is obtained to be 2.87, within the range of empirical value. The effective diffusion coefficient of the SFEF fractions in SiO2model catalyst is two orders of magnitude larger than that in FCC catalyst with the same average pore diameter. This indicate that besides the ratio of molecular diameter to the pore diameter λ, the effective diffusion coefficient is also closely related to the pore structure of catalyst. Because SiO2model catalyst has uniform pore size, the diffusion coefficient can be precisely correlated with pore size of catalyst, so it is a good model material for catalyst internal diffusion investigation.

The Preparation of High-Strength and Micropore Lightweight Bauxite Aggregate by In Situ Polymerization and Decomposition

2011 ◽  
Vol 194-196 ◽  
pp. 2135-2139
Author(s):  
Yi Neng Fang ◽  
Hua Zhi Gu ◽  
Yun Sheng Fen ◽  
Lin Jun Wang ◽  
Yan Jing Li
Keyword(s):  
Phase Composition ◽  
Pore Size ◽  
Aluminium Hydroxide ◽  
Average Pore Size ◽  
High Strength ◽  
Organic Polymer ◽  
Low Grade ◽  
Pore Former ◽  
Average Pore

High-strength and micropore lightweight bauxite aggregate was fabricated by low grade raw bauxite powder, aluminium hydroxide powder and organic polymer (OP). OP was used as consolidator, binder and pore former and aluminium hydroxide was used as pore former. The influence of OP and aluminium hydroxide content on the property of the samples was studied. The phase composition and the microstructure of the sintered samples were characterized by XRD, SEM and the pore size distribution was measured by mercury porosimety. The results demonstrate that the bulk density of the samples decreases linearly and the apparent porosity of the samples increases gradually with the addition of OP. The lowest density reached 1.13g/cm3when adding 35% OP and 10% Al(OH)3. The average pore size is around 5μm, and increases with the addition of OP increased. The XRD showed the main phase of the sample is mullite and some little amount of corundum.

scholarly journals Evaluation of Optimal Pore Size of (3-Aminopropyl)triethoxysilane Grafted MCM-41 for Improved CO2Adsorption

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Zhilin Liu ◽  
Yang Teng ◽  
Kai Zhang
Keyword(s):  
Pore Size ◽  
Pore Diameter ◽  
High Energy ◽  
Mesopore Volume ◽  
Average Pore ◽  
Major Drawback ◽  
Swelling Agent ◽  
Adsorption Capacities ◽  
Structural Regularity ◽  
Mcm 41

An array of new MCM-41 with substantially larger average pore diameters was synthesized through adding 1,3,5-trimethylbenzene (TMB) as the swelling agent to explore the effect of pore size on final adsorbent properties. The pore expanded MCM-41 was also grafted with (3-Aminopropyl)triethoxysilane (APTES) to determine the optimal pore size for CO2adsorption. The pore-expanded mesoporous MCM-41s showed relatively less structural regularity but significant increments of pore diameter (4.64 to 7.50 nm); the fraction of mesopore volume also illustrated an increase. The adsorption heat values were correlated with the order of the adsorption capacities for pore expanded MCM-41s. After amine functionalization, the adsorption capacities and heat values showed a significant increase. APTES-grafted pore-expanded MCM-41s depicted a high potential for CO2capture regardless of the major drawback of the high energy required for regeneration.

Fabrication of Porous SiAlON Using Fe2O3 as Pore Former

2014 ◽  
Vol 804 ◽  
pp. 267-270
Author(s):  
Qing Wen Duan ◽  
Rong Zhen Liu ◽  
Hai Yun Jin ◽  
Jian Feng Yang ◽  
Zhi Hao Jin
Keyword(s):  
Particle Size ◽  
Porous Materials ◽  
Pore Size ◽  
Fracture Mode ◽  
Size Effects ◽  
Pore Diameter ◽  
Bending Strength ◽  
Thermal Reduction ◽  
Pore Former ◽  
Median Pore

Porous SiAlON ceramics were fabricated by carbo-thermal reduction nitridation method using Fe2O3 as pore former. Particle size effects of Fe2O3 were reported in this paper. The results showed that composites were composed by SiAlON, AlN and Iron Silicon phases. The median pore diameter of Sialon was affected by the composition and particle size of Fe2O3. The fracture mode of this material was intergranular. With the increase of Fe2O3 additions, the porosity of this materials increased. The bending strength of this material was reversely proportional to Fe2O3 particle size. The maximum bending strength of Porous materials with 30wt.% Fe2O3 additions (with a porosity about 65% and the pore size is about 1μm) could reach 22 MPa. The porous Sialon ceramics with a smaller pore size exhibited a higher bending strength.

How to tailor the porous structure of alumina and aluminosilicate gels and glasses

1996 ◽  
Vol 11 (2) ◽  
pp. 518-528 ◽  
Author(s):  
V. Vendange ◽  
Ph. Colomban
Keyword(s):  
Porous Structure ◽  
Pore Structure ◽  
Pore Size ◽  
Boron Oxide ◽  
Pore Diameter ◽  
Average Pore Diameter ◽  
Mesoporous Aluminosilicates ◽  
Average Pore ◽  
Impregnation Process ◽  
Size And Structure

Optically clear monolithic (OCM) gels of mesoporous aluminosilicates (average pore diameter 3.6 nm) and alumina (6 nm) have been prepared by slow hydrolysis-polycondensation of alkoxides and converted into OCM mesoporous glasses by heating. In order to change the properties, different ways of modifying the pore size and structure are proposed. We show that addition of boron oxide reduces the average pore diameter. A higher effect can be obtained by addition of a surfactant. In this case the mesoporous matrix becomes microporous (d < 2 nm). Another way of modifying the pore structure consists of introducing nanoprecipitates inside the porosity by an impregnation process. Modifications of the porous structure are different in alumina and aluminosilicates.

scholarly journals Carbon Dioxide Adsorption in Nanopores of Coconut Shell Chars for Pore Characterization and the Analysis of Adsorption Kinetics

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Chaiyot Tangsathitkulchai ◽  
Supunnee Junpirom ◽  
Juejun Katesa
Keyword(s):  
Pore Size ◽  
Adsorption Kinetics ◽  
Average Pore Size ◽  
Total Pore Volume ◽  
Carbonization Temperature ◽  
Coconut Shell ◽  
Average Pore ◽  
Porous Texture ◽  
Gcmc Simulation ◽  
Transient Measurement

The uptake data of CO2 adsorption at 273 K by coconut shell chars prepared at various carbonization temperatures from 250 to 550°C were used for characterizing pore texture of chars as well as the analysis of CO2 adsorption kinetics. The equilibrium isotherms were used to determine the porous texture of chars, employing the DR equation and GCMC simulation. It was found that all the test chars contain micropores of a size range from 0.8 to 2.2 nm with the pore size distribution becoming wider for char prepared at a higher carbonization temperature. Porous properties of chars, including surface area, total pore volume, and the average pore size, appear to increase with an increasing carbonization temperature. The analysis of CO2 uptake during the transient measurement of isotherms revealed that the kinetics of CO2 adsorption is governed by the internal diffusional transport of the adsorptive molecules. The effective pore diffusivity characterizing this transport process increases with increasing CO2 loading and passes through a maximum at a certain loading. This maximum pore diffusivity shifts to a higher value as the carbonization temperature is increased. A semiempirical equation was developed to correlate the effective pore diffusivity of CO2 with the equilibrium adsorption loading and its predictive capability is satisfactory.

Research on the Relationship between Permeability and Pore Size Characteristics of Microporous Nonwoven Geotextile

2013 ◽  
Vol 753-755 ◽  
pp. 792-797 ◽  
Author(s):  
Bing Xuan Ni ◽  
Peng Zhang
Keyword(s):  
Pore Size ◽  
Pore Diameter ◽  
Average Pore Diameter ◽  
Flow Index ◽  
Hydraulic Permeability ◽  
Measuring Instrument ◽  
Average Pore ◽  
Vertical Permeability ◽  
Nonwoven Geotextile ◽  
The Relationship

The hydraulic permeability performance of geosynthetics is an important functional technical index in the field of engineering application. In this paper, the pore size characteristics of a series different specifications of spunbond and needlepunched nonwoven geotextile has tested through capillary flow aperture measuring instrument, including average pore diameter, maximum pore size and pore size distribution. The permeability characteristics of nonwoven geotextile has measured by vertical permeability measuring instrument, including flow index and vertical permeability coefficient. We study on the compressive properties of nonwoven geotextile under the different pressure, through the relationship between the average pore diameter and flow index to fit curve, and built the regression equation, so we can calculate and predict the water permeability performance through pore size Characteristics.

Experimental Research on the Preparation of Porous Activated Carbon from Orange Wastes

2009 ◽  
Vol 79-82 ◽  
pp. 1907-1910
Author(s):  
Zhi Gang Xie
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Pore Volume ◽  
Pore Diameter ◽  
Total Pore Volume ◽  
Carbonization Temperature ◽  
Bet Surface Area ◽  
Average Pore ◽  
Impregnation Ratio ◽  
Heat Preservation

Porous activated carbon was prepared from orange wastes using zinc chloride as an activating agent by one-step carbonization method. Effects of impregnation ratio, carbonization temperature and heat preservation time on pore characteristics of activated carbon were studied. The porous structures of the orange wastes activated carbon were investigated by BET, D-R equations, BJH equations and Kelvin theory. The morphology was observed using transmission electron microscopy (TEM). The mesoporous activated carbon is gained when the impregnation ratio is 3:1; the carbonization temperature is 550°Cand heat preservation time is 1.0 h. The activated carbon has total pore volume 2.098 cm3/g, mesoporous pore volume 1.438 cm3/g, with a high BET surface area 1476m2/g. The pore distribution of the mesoporous activated carbon is very concentrative, with average pore diameter of 3.88nm. While, the high specific surface area activated carbon is gained when the impregnation ratio is 2:1; the carbonization temperature is 550°Cand heat preservation time is 1.0 h. The activated carbon has high BET surface area 1909 m2/g, while the total pore volume is only 1.448cm3/g and microporous pore volume is 0.889cm3/g, with average pore diameter of 2.29 nm.

Structural Characterization of MMT Modified by Acrylamide

2011 ◽  
Vol 689 ◽  
pp. 425-431
Author(s):  
Zeng Zhi Zhang ◽  
Dan Dan Ma
Keyword(s):  
Pore Size ◽  
Lamellar Structure ◽  
Heating Temperature ◽  
Average Pore Size ◽  
Lamellar Spacing ◽  
Treatment Temperature ◽  
Carbonization Temperature ◽  
Average Pore ◽  
Heating Treatment

Carbon pillared MMT was prepared from Na-MMT modified by acrylamide. The structural behavior of the MMT and AM/modified MMT were characterized by TG-DTA and DSC. The analysis of modified MMT showed that: the lamellar structure of carbon pillared MMT increases clearly with the carbonization temperature. In the experiment temperature range, the higher the heating temperature, the more significantly carbonization properties of MMT exhibited, and the more apertures of Pillared MMT developed. In the test MMT lamellar spacing of the carbide change with the heating treatment temperature, d001 value of the MMT augmented to the largest when carbonization temperature reach 200°C; the average pore size of treated MMT was larger than untreated MMT, the pore size became the largest average at 400 °C.

Quantitative stereological analysis of the pore-size distribution in a colloidal silica sol-gel

1990 ◽  
Vol 48 (4) ◽  
pp. 1078-1079
Author(s):  
Helen M. Kerch ◽  
Rosario Gerhardt
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Diameter ◽  
Sol Gel ◽  
Image Analyzer ◽  
Average Pore ◽  
Thin Sections ◽  
Stereological Analysis ◽  
Colloidal Gel

The pore size distribution of an unsintered colloidal gel has been determined by stereological analysis of ultramicrotomed thin sections (70 nm) of the gel. This is a novel use of the ultramicrotomy technique as the epoxy represents the porous phase of the microstructure rather than just the medium used to maintain a coherent structure during thinning. In order to obtain statistically significant pore size information a nested sampling scheme was carried out, and a total of 36 two-dimensional fields taken at 19,000 X were examined. Pore diameters were measured with a digital image analyzer which measured 15 projected diameters every 12° from the center of the feature. Stereological quantities obtained were average pore diameter (Davg), number of pores per unit area (NA), and number of pores per unit volume (NV).

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