Fabrication and Properties of Alumina Flat Sheet Membrane Surports

2014 ◽  
Vol 955-959 ◽  
pp. 601-604
Author(s):  
De Xiang Liao ◽  
An Chao Geng ◽  
Peng Hao Su ◽  
Dao Lun Feng ◽  
Lin Lin Wang

The porous ceramic support was realized at various temperature range from 1200°C~1300°C using α-Al2O3 as main material, carbon powder as pore-former, kaolin clay and titanium dioxide as sintering aids and polyvinyl alcohol (PVA) as adhesives. The microstructures of sintered body were significantly affected by the amount of pore-former and sintering temperature. The results indicated that the porosity dramatically increased and the pore radius increased from 2.9 μm to 3.2 μm as carbon powder addition increased from 3 wt.% to 12 wt.%. Correspondingly, their pure water flux depending on the pore structure parameters of the support increased from 1.37 to 4.53 m3.m-2.h-1.bar-1. To prepare porous alumina support with 40% open porosity, carbon powder up to 10 wt.% is appropriate. Sintering experiments showed that the optimum sintering conditions are the sintering temperature of 1300 °C and 2 h holding time at this temperature.

2017 ◽  
Vol 79 (1-2) ◽  
Author(s):  
Siti Khadijah Hubadillah ◽  
Mohd Hafiz Dzarfan Othman ◽  
A. F. Ismail ◽  
Mukhlis A. Rahman ◽  
Juhana Jaafar

Ceramic hollow fibre membrane (CHFM) demonstrated superior characteristics and performance in any separation application. The only problem associated with this kind of technology is the high cost. In order to effectively fabricate and produce low cost porous CHFM, a series of CHFMs made of kaolin were fabricated via combined phase inversion and sintering technique. The CHFMs from kaolin named as kaolin hollow fibre membranes (KHFMs) were studied at different kaolin contents of 35 wt.%, 37.5 wt.% and 40 wt.% sintered at 1200ºC. The result indicated that by varying kaolin contents, different morphologies were obtained due to changes in the viscosity of ceramic suspension containing kaolin. The optimum kaolin content for KHFM was identified. It was found that KHFM prepared at 37.5 wt% has a mechanical strength and pure water flux of A and B respectively.  


2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Jincai Su ◽  
Yanyan Wei ◽  
Hui Li

In this study, robust and defect-free thin film composite (TFC) forward osmosis (FO) membranes have been successfully fabricated using ceramic hollow fibers as the substrate. Polydopamine (PDA) coating under controlled conditions is effective to reduce the surface pores of the substrate and make the substrate smooth enough for the interfacial polymerization. The pure water permeability (A), solute permeability (B) and structural parameter (S) of the resultant FO membrane are 0.854 L·m-2h-1bar-1 (LMH/Bar) 0.186 L·m-2h-1 (LMH) and 1720 µm, respectively. The water flux and reverse draw solute flux are measured using NaCl and proprietary ferric sodium citrate (FeNaCA) draw solutions at low and high osmotic pressure ranges. With increasing the osmotic pressure, higher water flux is obtained but its increase is not directly proportional to the increase in the osmotic pressure. At the membrane surface, the effect of dilutive concentration polarization is much less serious for FeNaCA draw solutions. At an osmotic pressure of 89.6 bar, the developed TFC membrane generates water fluxes of 11.5 and 30.0 LMH using NaCl and synthesized FeNaCA draw solutions. The corresponding reverse draw solute flux is 7.0 g·m-2h-1 (gMH) for NaCl draw solution but it is not detectable for FeNaCA draw solution. This means that the developed TFC FO membranes are defect free and their surface pores are at molecular level. The performance of the developed TFC FO membranes are also demonstrated for the enrichment of BSA protein.


2014 ◽  
Vol 805 ◽  
pp. 272-278 ◽  
Author(s):  
Antonielly dos S. Barbosa ◽  
Antusia dos S. Barbosa ◽  
Meiry Glaucia F. Rodrigues

Much interest has been aroused in the application in industrial processes using zeolite membrane, due to its crystalline structure, and narrow pore diameters. These features enable the continuous separation of mixtures based on differences in molecular size and shape and also based on different adsorption properties. This paper reports the synthesis of MCM-22 zeolite membrane, using the method of secondary growth. The MCM-22 zeolite was synthesized by the hydrothermal method and characterized by spectroscopy Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM).The ceramic support (α-alumina) was prepared using the technique of forming powder and then subjected to the sintering temperature of 1400 °C/1h and characterized by XRD. The zeolite membrane preparation was performed by the method of secondary growth and characterized by XRD, SEM and mercury porosimetry. The obtained zeolite membrane could be confirmed by X-ray diffraction. From, the obtained SEM pictures it was possible to observe the formation of a homogeneous film on the zeolite surface of the ceramic support (α-alumina).


2012 ◽  
Vol 538-541 ◽  
pp. 29-32
Author(s):  
Jing Diao ◽  
Jian Feng Xu ◽  
Song Tao Li ◽  
Xiao Hui Cao ◽  
Chun Yi Liu ◽  
...  

Polyethersulfone (PES) flat sheet membranes were prepared via phase inversion induced by immersion precipitation from a novel lower critical solution temperature (LCST) system containing PES, 1-butanol and N, N-dimethylacetamide. And the effect of coagulation bath temperature on the properties and structure of PES membranes were investigated. The results show that the pure water flux increases and the tensile strength decreases as the coagulation temperature increases form 20°C to 50°C. Besides, the SEM images shows that all of the membranes prepared from a LCST system at different CBT own sponge-like structures.


2017 ◽  
Vol 9 (1) ◽  
Author(s):  
B. Darunee ◽  
C. Nucharee ◽  
B. Tripob

Porous ceramics membranes were prepared from ternary mixtures of Ranong kaolin, calcium carbonate and silica using slip casting technique. Totally 10 different composition mixtures were selected from the ternary diagram of CaCO3 : SiO2 : Clay with weight fraction of 0–0.19 : 0.28–0.47 : 0.52–0.71, respectively. The ceramic paste was first fired at 800°C and then sintered at temperatures of 1200, 1250 and 1300°C. The results show that firing temperature above 1200°C is probably too high to prepare the porous ceramics of the studied compositions. The porosity less than 26% is obtained from the samples sintered at 1250–1300°C. The highest porosities of more than 40% are observed from the samples sintered at 1200°C with the weight fraction of clay, calcium carbonate and silica between 0.524–0.562, 0.076–0.152, and 0.310–0.394, respectively. In this range of compositions, the linear shrinkage and water absorption is about 3% and 22%, respectively, while the bending strength is between 28–30 MPa. The pure water flux of samples prepared from mixture formula 9 sintered at 1200°C ranges between 52.4 and 368.8 L/m2.h at the operating pressures 30–120 kPa, indicating that the mixture compositions nearby the formula 9 are the best for porous ceramic production using Ranong kaolin.


2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Nurul Nabilah Aminudin ◽  
Hatijah Basri ◽  
Zawati Harun ◽  
Muhamad Zaini Yunos ◽  
Goh Pei Sean

PSf flat sheet membrane was prepared via phase inversion technique with N-methyl-2-pyrroidone (NMP) as solvent. In this study polyethylene glycol (PEG) and polyvinylpyrollidone (PVP) were compared as additives at different composition (0.5 wt%, 1 wt%, 3 wt% and 5 wt%). The structure and morphology of the resulting membranes were observed by scanning electron microscope (SEM) and the membranes permeation were evaluated in terms of pure water flux (PWF) and solute rejection. Solution of bovine serum albumin (BSA) was used to study the performance of prepared membrane. The addition of the additives into the casting solution changed the structure of the resultant membranes, which was believed to be associated with the change the permeated of water. The results demonstrated that at the same additive content, PSf/PVP membranes had higher PWF at 0.5 wt% and and 5 wt% of additive while PSf/PEG at 1 wt% and 3 wt% of additive. The BSA rejection show no significant changes for PSf/PEG while PSf/PVP, BSA rejection decrease with increase the increasing the PVP. For PEG, additive from 0% to 5%, the PWF increased from 14.73 at to 101.85 LMH. While for PVP, the PWF increased from 21.13 to 177.61 LMH. The membrane morphology showed that all images showed the membranes were having asymmetric structure consisting of a dense top layer, a porous sublayer, and a small portion of sponge-like bottom layer. The top layer of the membrane consist of finger-like structure while at bottom layer  has macrovoid structure. With increasing the additive, the finger-like structure become longer to the bottom  and macrovoid become smaller. The study found that PEG gives the optimum performance based on the result of rejection and flux permeation.


2016 ◽  
Vol 15 (2) ◽  
pp. 1
Author(s):  
Syafikah H Paiman ◽  
Mukhlis A A Rahman ◽  
Mohd Hafiz Dzarfan Othman ◽  
Siti Halimah Ahmad

Recently, ceramic membrane gradually acquired attention from researchers due to the advantages of ceramic’s behavior, which allows the ceramic to overcome the limitations of using polymeric membrane. This work focused on the fabrication of ceramic hollow fibre membrane from a ceramic suspension solution containing yttria-stabilized zirconia (YSZ), polyethersulfone (PESf), N-methylpyrrolidone (NMP) and dispersants using combined phase inversion sintering technique. In this study, ceramic hollow membrane precursors were sintered at different sintering temperature ranging between 1250°C and 1400°C. The influences of sintering temperature on the microstructure, porosity and pore size distribution, mechanical strength and pure water flux of ceramic hollow fibre membrane were investigated in detail. The results show an asymmetric structure of YSZ hollow fibre membrane containing finger-like structure and sponge-like structure. The sponge-like structure can serve as a separation layer, while finger-like-structure performs as a supported layer. It is observed that sintering process caused a significant densification of sponge-like structure (microstructure). Sintering at temperature 1400°C shows the formation of non- interconnected voids. Sintering at 1300°C is sufficient enough having a mechanical strength of 227.55MPa with an apparent porosity of 45.09% and PWF of 118.39L.m¯².hr¯¹.


2013 ◽  
Vol 544 ◽  
pp. 56-59 ◽  
Author(s):  
Qi Bing Chang ◽  
Ke Yang ◽  
Xia Wang ◽  
Ke Kai Cheng ◽  
Yong Qing Wang ◽  
...  

The high sintering temperature of Al2O3 is the main reason of the high cost of the common ceramic membrane supports. To decrease the sintering temperature, kaolin and talc were chosen as sintering aid because the reaction between kaolin, talc and Al2O3 generates cordierite. The Al2O3-cordierite porous ceramic samples were sintered in the range of 1450~1510°C. The microstructure and the bending strength of the samples were characterized. The results show that the content of kaolin is no more than 8%, the bending strength of the porous ceramic sintered at 1460°C and 1510°C are 77MPa and 153MPa, respectively. The further increases of the kaolin content result in the decrease of the bending strength and the porosity. The needle-like cordierite locates in the neck of Al2O3 grains. The reaction between kaolin and Al2O3 contributes to increasing the sintering velocity. The ceramic support using cordierite as sintering aid has the acid/alkali corrosion resistance in some degree.


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