scholarly journals Characteristics of unsupported alumina membrane prepared using sol-gel technique

2017 ◽  
Vol 18 (2) ◽  
Author(s):  
M.R. Othman, ◽  
A.L. Ahmad, ◽  
And H. Mukhtar
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Alumina Membrane ◽  
Porous Support ◽  
Porosity Level ◽  
Gel Layer ◽  
Gel Technique ◽  
Coating Time

A laboratory scale alumina membrane was prepared using sol-gel technique. Results from the experiment demonstrate that the addition of PVA is important for viscosity adjustment to determine the appropriate coating time if the membrane is required for coating on the porous support. The effects of varying PVA content and sintering temperature on the characteristics of the sintered membrane are discussed. In this work, a 2 volume % of PVA solution containing 4g of PVA in lOOml of water was discovered to be adequate to achieve appropriate porosity level and avoid cracks in the gel layer. It was also discovered that the sol viscosity essentially increased as the PVA addition was increased. On the contrary, the coating time decreased as PVA content in the sol was increased. Generally, the pore size of the membrane increased with the increase in PVA addition. The density of the membrane increased with increase in sintering temperature. The porosity level however, decreased as the temperature was increased. The pore size became greater and pore size distribution wider at higher sintering temperatures. 

scholarly journals Characteristics of unsupported alumina membrane prepared using sol-gel technique

2017 ◽  
Vol 18 (2) ◽  
Author(s):  
M.R. Othman, ◽  
A.L. Ahmad ◽  
H. Mukhtar
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Alumina Membrane ◽  
Porous Support ◽  
Porosity Level ◽  
Gel Layer ◽  
Gel Technique ◽  
Coating Time

A laboratory scale alumina membrane was prepared using sol-gel technique. Results from the experiment demonstrate that the addition of PVA is important for viscosity adjustment to determine the appropriate coating time if the membrane is required for coating on the porous support. The effects of varying PVA content  and sintering temperature on the characteristics of the sintered membrane are discussed. In this work, a 2 volume % of PVA solution containing 4g of PVA in lOOml of water was discovered to be adequate to achieve appropriate porosity level and avoid cracks in the gel layer. It was also discovered that the sol viscosity essentially increased as the PVA addition was increased. On the contrary, the coating time decreased as PVA content in the sol was increased. Generally, the pore size of the membrane increased with the increase in PVA addition. The density of the membrane increased with increase in sintering temperature. The porosity level however, decreased as the temperature was increased. The pore size became greater and pore size distribution wider at higher sintering temperatures.

Study on the Properties of Al-Al2O3 Composite Using Synthesized Alumina from Sol Gel Technique

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Hasmaliza Mohamad ◽  
Hanisah Abdul Rani
Keyword(s):  
Metal Matrix ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Comparison Study ◽  
Commercial Alumina ◽  
Al2o3 Composite ◽  
Alumina Particles ◽  
Gel Technique ◽  
Ideal Method ◽  
The Ideal

Alumina reinforced aluminum is one of metal matrix composite (MMC) systems that can maintain its properties although at high temperature. Among various processes to produce MMC, powder metallurgy is the best method because of its efficiency dispersion of fine alumina particles. In this study, alumina powders were synthesized through sol gel method which is known as one of the ideal method to produce good properties of powders. The performances of synthesized alumina powders were then observed through the fabrication of composite. The percentage of alumina (0wt%, 10wt%, 20wt% and 30wt %) and sintering temperature (500°C and 550°C) were varied in order to observed their effects on the produced composite. Result shows that by increasing the percentage of alumina and sintering temperature, mechanical properties were increased where 30wt% alumina and 550°C sintering temperature give the optimum results. Comparison study by using 30wt% alumina and 550°C sintering temperature on the composite using synthesize and commercial alumina shows similar/comparable properties of composite.

Thermal Conductivity of Sol-Gel Bonded Castables

2008 ◽  
Vol 368-372 ◽  
pp. 1146-1148
Author(s):  
Feng Cao ◽  
C.Y. Wang ◽  
P.S. Tang ◽  
C.Y. Lu ◽  
H.F. Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Glassy Phase ◽  
Size Structure ◽  
Sol Gel ◽  
Refractory Castables ◽  
Silica Alumina ◽  
Alumina Sol

The silica-alumina sol bonding agent, prepared by the sol gel route from ethyl silicate and aluminium isopropanol, was utilized in the refractory castables. The influence of structure on the heat transfer has been investigated using different sorts of refractory matrix. The results indicated that the heat conductivity of sol-gel bonded castables was considerably affected by their structure. The phase composition of matrix, porosity, pore size distribution and pore size structure were the most important factors. Thermal conductivity has been measured from the ambient temperature up to 1250 °C. The influence of crystalline phases and the glassy phase formation and the influence of the pore size distribution on the thermal conductivity were also described in this work.

Production of Porous Cordierite through Sol-Gel Polymeric Sponge Method

2012 ◽  
Vol 620 ◽  
pp. 127-131 ◽  
Author(s):  
Mohamad Hasmaliza ◽  
M. Siti Naqiah ◽  
R.J. Shafinaz ◽  
Ibrahim Norfadhilah
Keyword(s):  
Pore Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
High Melting ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Melting Temperature ◽  
Sem Micrograph ◽  
Porous Cordierite ◽  
Scanning Electron

Cordierite (2MgO.2Al2O3.5SiO2) is widely used in high temperature applications due to its high melting temperature and high resistance to thermal shock, chemical and corrosion. In this study, porous cordierite was synthesized using sol-gel method followed by replication of polymeric sponge method. Three different sintering temperatures were studied (1200°C, 1300°C and 1400°C to determine the crucial temperatures meant for pure cordierite phase. The effect of different temperature on the pore size, density and porosity were also studied. Produced porous cordierite was then analyzed using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). XRD results showed that pure cordierite phase was obtained at 1300°C. SEM micrograph shows that with increasing sintering temperature, the pore size decreased and sample sintered at 1300°C has pore size ranging from 61-126μm.

Theory of Nuclear Relaxation in Confining Systems. Application to Non Wetting Liquids in Porous Silica Glasses

1992 ◽  
Vol 290 ◽  
Author(s):  
J.-P. Korb ◽  
A. Delville ◽  
Shu Xu ◽  
J. Jonas
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Sol Gel ◽  
Porous Silica ◽  
Nuclear Relaxation ◽  
Narrow Pore Size Distribution ◽  
Silica Glasses ◽  
Frequency Dependences ◽  
Wetting Liquid

AbstractThis work shows how the geometrical confinements enhances the nuclear relaxation of a non wetting liquid in a model porous systems. Application of the proposed theory is made to interpret the size and frequency dependences of the 1H relaxation of methylcyclohexane liquid in sol-gel porous silica glasses with narrow pore-size distribution.

scholarly journals Conducting Membranes and Coatings made from Redispersable Nanoscaled Crystalline SnO2:Sb Particles

1998 ◽  
Vol 520 ◽  
Author(s):  
C. Goebbert ◽  
M. A. Aegerter ◽  
D. Burgard ◽  
R. Nass ◽  
H. Schmidt
Keyword(s):  
Thermal Treatment ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Sol Gel ◽  
Total Porosity ◽  
Solid Content ◽  
Visible Range ◽  
Inorganic Membranes ◽  
Separation Processes

ABSTRACTInorganic membranes prepared by the sol gel method are promising candidates for use as filters in separation processes. Conducting supported membranes and coatings have been produced from redispersable nanoscaled crystalline Sb-doped SnO2 powders with a Sb content up to 5 mole % (with respect to Sn). The crystalline particles are monosized (≅4 nm) and fully redispersable in aqueous solution at pH ≥ 8 with a solid content up to 70 wt. %. By thermal treatment at different temperatures and times, the pore size diameter of the material can be adjusted from 4 to 20 nm with a very narrow pore size distribution (∼ ±1 nm) and a total porosity of 63 %, practically independent of the sintering parameters. Uniaxial pressed substrates present similar characteristics with however larger pore size distribution (±5 nm) and 80 % total porosity. Their resistance decreases with sintering temperature and time down to 4 Ω (800 °C 8 h). Fully dispersed aqueous solutions of the powder (25 wt. %) were used to prepare transparent conducting coatings on glass or ceramics by spin-coating. After thermal treatment (1 hour at 550 °C) single layers 200 nm thick exhibited a typical specific electrical resistance ρ = 2.5·10−2 ωcm with transmission in the visible range measured against air of 90%.

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