Effects of Pore Former on Properties of Alumina Porous Ceramic for Application in Micro-Filtration Membrane Supports

2015 ◽  
Vol 655 ◽  
pp. 97-102 ◽  
Author(s):  
Qi Fu Bao ◽  
Wei Xia Dong ◽  
Jian Er Zhou ◽  
Yong Qing Wang ◽  
Yang Liu
Keyword(s):  
Compressive Strength ◽  
Pore Diameter ◽  
Porous Ceramic ◽  
Pore Former ◽  
Average Pore ◽  
Temperature Resistance ◽  
Ceramic Composition ◽  
Filtration Membrane ◽  
First Choice ◽  
Mercury Porosimeter

Due to its excellent chemical stability, high temperature resistance and mechanical properties, alumina porous ceramic was the first choice of the production of microfiltration membrane support body material. In this paper, alumina porous ceramic was prepared by alumina as main materials and adding proper amount of adhesives and sintering additives. Effects of the kinds and addition of pore formers, such as starch, graphite and carbon-black, on properties of alumina porous ceramic was studied. The porosity of the fired samples was evaluated by Archimedes law. The fired samples were characterized by scanning electron microscopy (SEM), compressive strength and mercury porosimeter measurements. Alumina porous ceramic composition was prepared by mixing 100% alumina with different particle size and 8 % graphite pore former. The sample was pressured at 10 MPa and fired at 1650 °C for 2 h, and endowed with 6-8 μm of the average pore diameter, 37.65 % of the porosity and 40.33 MPa of the compressive strength, respectively. The influence law of the kinds and addition of graphite pore former on the performance of alumina porous ceramic was studied for application in micro-filtration mmembrane supports.

scholarly journals Isothermal Drying Process and its Effect on Compressive Strength of Concrete in Multiscale

2019 ◽  
Vol 9 (19) ◽  
pp. 4015
Author(s):  
Du ◽  
Li ◽  
Tong ◽  
Li ◽  
Liu
Keyword(s):  
Compressive Strength ◽  
Pore Diameter ◽  
Strengthening Effect ◽  
Drying Process ◽  
Average Pore ◽  
Competition Result ◽  
Compressive Strength Of Concrete ◽  
Paste Content ◽  
Isothermal Drying ◽  
Microstructural Studies

Drying could change the microstructure of cement-based materials and inevitably affect their mechanical properties. The isothermal drying process of concrete at three scales and its effect on compressive behavior and microstructure were investigated. The deformations of cement paste, mortar, and concrete in the drying process all exhibit the characteristics of expansion first and then shrinkage. The porosity and average pore diameter increase after drying, which is mainly attributed to the increase of pores less than 100 nm diameter for paste and to the pores within 100~1000 nm for mortar. Drying makes paste denser, while the bonding between paste and aggregate is weakened. Microstructural studies indicate that the increase in compressive strength of concrete caused by isothermal drying is the competition result between the strengthening effect and the weakening effect, and is related to the paste content.

Preparation and Research of Porous Hydroxyapatite Whiskers/KGM Composite Bone Scaffolds

2013 ◽  
Vol 712-715 ◽  
pp. 415-419
Author(s):  
Ming Hua Huang ◽  
Qing Hua Chen ◽  
Li Lei ◽  
Duan Cheng Wang ◽  
Ting Ting Yan
Keyword(s):  
Compressive Strength ◽  
Degradation Rate ◽  
Pore Diameter ◽  
Sol Gel ◽  
Crosslinking Agent ◽  
Average Pore Diameter ◽  
Average Pore ◽  
Bone Scaffolds ◽  
Composite Bone

Sol-gel method and freeze-drying method were adopted to prepare the porous HAPw/KGM composite bone scaffolds and ammonia was used as a crosslinking agent. The porosity, average pore diameter, compressive strength and degradation rate in vitro were measured according to the related standard. The curves of each factor and lever affecting comprehensive properties were drew through the orthogonal design L9 (34) experiment. SEM and XRD were applied in characterization. The results show that the optimal preparation program of the composite scaffolds is KGM (2g), HAPw (4.5g), ammonia (0.1 ml) and the freeze temperature (-20 ° C); the prepared scaffolds are porous three-dimensional network structures; the porosity of optimal scaffold is more than 90%; the average pore diameter is between 200-300μm; the compressive strength is about 0.8Mpa and the degradation rate is about 50% within 9 weeks.

Preparation of SiC Porous Ceramic for Application in Filter Plate Supports

2016 ◽  
Vol 848 ◽  
pp. 237-242 ◽  
Author(s):  
Qi Fu Bao ◽  
Wei Xia Dong ◽  
Jian Er Zhou ◽  
Xiao Chun Hu
Keyword(s):  
Bending Strength ◽  
Porous Ceramic ◽  
Heavy Metal Concentration ◽  
Close Packing ◽  
Production Costs ◽  
Ceramic Filter ◽  
Molding Pressure ◽  
High Porosity ◽  
Pore Former ◽  
Average Pore

In order to improve the efficiency of solid-liquid separation, dewatering and filtration, as well as to reduce the loss of concentrate and production costs, silicon carbide porous ceramic filter plate with high porosity and high bending strength was prepared by using the particles close packing method adding proper amount of adhesives and sintering additives at 1450 oC. The porosity of the fired samples was evaluated by Archimedes law. The morphology and properties of the samples were characterized. Effects of SiC grains gradation, pore formers content, molding pressure and soaking time on the bending strength and porosity of ceramic filter plate was studied. SiC porous ceramic composition was prepared by mixing 90wt% and 10wt% SiC powders with D50 of 200.7 μm and 312.6 μm, respectively, 4% walnut powder as pore former and 5% Kaolin clay as binder. The sample was pressured at 8 MPa and fired at 1450 oC for 30 min, and endowed with 6-8 μm of the average pore diameter, 41% of the porosity and 11 MPa of the bending strength, respectively, which is especially not easy to plug hole. The obtained results can be applied in ceramic filter core parts for heavy metal concentration.

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.

Effect of Low Content of Metakaolin Addition on the Properties and Pore Structure of Concrete

2016 ◽  
Vol 680 ◽  
pp. 411-419
Author(s):  
Hai Ning Geng ◽  
Qiu Li ◽  
Zhi Guang Shi ◽  
Zhong He Shui
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Pore Diameter ◽  
Analytical Techniques ◽  
Average Pore Diameter ◽  
Average Pore

The properties and microstructure of concrete containing 0-6wt% metakaolin (MK) were studied by analytical techniques. The compressive strength increased with the content of MK and reached the maximum by 5wt% MK addition, where the compressive strength increased by 33% at 28 days comparing to the control. The pore structure was refined in the concrete containing MK due to the increase of amount of pores smaller than 10 nm. There is a relationship between average pore diameter and compressive strength.

Fabrication of Glass Foams from Industrial Wastes Used as Insulating Board

2013 ◽  
Vol 770 ◽  
pp. 205-208 ◽  
Author(s):  
K. Pawanawichian ◽  
W. Thiemsorn ◽  
Anucha Wannagon ◽  
P. Laoarun
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Cell Walls ◽  
Pore Diameter ◽  
Sintering Temperature ◽  
Industrial Wastes ◽  
Average Pore ◽  
Wet Process ◽  
Commercial Soap ◽  
Glass Foam

nsulating glass foam (IGF) was successfully fabricated by wet process. The starting proportion of 65 wt% waste glass, 12 wt% slag, 23 wt% commercial soap was added with 15 wt% Na2SiO3 and represented then was sintered at 725 °C. The IGF had cellular structure with the macro-pore size at 0.428 mm and thin cell walls. Density, thermal conductivity and compressive strength were 0.310 g/cm3, 0.130 W/m.K and 0.78 MPa, respectively. The average pore diameter and porosity increased with increasing the Na2SiO3 concentration and the sintering temperature. On the other hand, the density, thermal conductivity and compressive strength were decreased.

Fuels Desulphurisation by Adsorbtion on Fe / Bentonite

2017 ◽  
Vol 68 (3) ◽  
pp. 483-486
Author(s):  
Constantin Sorin Ion ◽  
Mihaela Bombos ◽  
Gabriel Vasilievici ◽  
Dorin Bombos
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Pore Diameter ◽  
Adsorption Process ◽  
Continuous System ◽  
Gas Oil ◽  
Average Pore ◽  
Atmospheric Distillation

Desulfurisation of atmospheric distillation gasoline and gas oil was performed by adsorption process on Fe/ bentonite. The adsorbent was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments of atmospheric distillation gasoline and gas oil were performed in continuous system at 280�320oC, 5 atm and volume hourly space velocities of 1�2 h-1. The efficiency of adsorption on Fe / bentonite was better at desulphurisation of gasoline versus gas oil.

scholarly journals Photocatalytic activity of Pr-modified TiO2 for the degradation of bisphenol A

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Denise S. Cordeiro ◽  
Fernando L. Cassio ◽  
Larissa Ciccotti ◽  
Thiago L. R. Hewer ◽  
Paola Corio ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Bisphenol A ◽  
Pore Diameter ◽  
Sol Gel ◽  
Bandgap Energy ◽  
Photocatalytic Efficiency ◽  
Average Pore ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Adsorption Desorption

AbstractPraseodymium doped TiO2 nanoparticles were successfully prepared by the sol–gel method and characterized by X-ray powder diffraction, N2 adsorption–desorption isotherm, and UV–vis spectroscopy. The effects of the dopant on the crystallite size, specific surface area, average pore diameter, pore volume, and bandgap energy were investigated. The photocatalytic activity of the catalysts was evaluated by bisphenol A degradation and mineralization, which is a representative endocrine disruptor. Furthermore, under visible light irradiation the Pr-modified TiO2 photocatalysts exhibited higher photocatalytic efficiency than unmodified TiO2. When praseodymium was loaded (1.0–5.0%) onto the surface of TiO2, the rates of degradation and mineralization were increased 3–5 times.

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.

Pore Structure and Mechanical Properties of ZrC/SiC Multi-Components Modified C/C Composites

2013 ◽  
Vol 833 ◽  
pp. 159-164 ◽  
Author(s):  
Xiu Qian Li ◽  
Hai Peng Qiu ◽  
Jian Jiao
Keyword(s):  
Mechanical Properties ◽  
Pore Diameter ◽  
Testing Machine ◽  
Average Pore Diameter ◽  
Flexural Properties ◽  
Matrix Interface ◽  
Polymeric Precursor ◽  
Average Pore ◽  
Fiber Matrix Interface ◽  
Injection Apparatus

The ZrC/SiC multi-components modified C/C composites were prepared by using a hybrid precursor containning polycarbosilane and organic zirconium-contained polymeric precursor as impregnant and C/C composites of low density as preform. The porosity, microstructure and mechanical properties of samples were characterized with mercury injection apparatus, scanning electron microscopy and universal electron testing machine respectively. The results show that the porosity and average pore diameter decrease firstly and increase subsequently with the increase of organic zirconium content of the precursor. When the content of organic zirconium is 50%, the porosity and average pore diameter reach minimum which were7.27% and 0.0795um respectively. The most probabilistic pore diameter shifted from 10-100um to 1-10um at the same time; Meanwhile, the flexural properties also increases and drops immediately as the content of organic zirconium in the precursor adds. When the content of organic zirconium is 25%, the flexural strength reaches maximum of 245.20MPa.The improved flexural properties is attributed to the proper bonding of fiber-matrix interface and the low porosity of samples.

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