• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.312-313
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• 2006

The primary aim pursued by the preparation of separation membrane is the preparation of the membrane thin as well as with no defect. The field-flow fractionation deposition is a new molding technology which can overcome the traditional disadvantages such as multi-preparation to the preparation of great area of separation membrane with no defect. Therefor the mainly ingredients which influence the appearance and performance of titanium membrane layer are investigated by scanning electricity mirror (SEM) as well as porous material testing instrument: powder performance prepared and confected; selection of supporting body; sintering system such as temperature and time. It is shown that the membrane thickness can be controlled at $50{\mu}m$ or so; the filtration precision mainly rests with powder performance and selection of supporting body and little sintering system

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.39-45
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• 1968

Recently, in this department, pressure-displacement curve and breaking tension of dog and human tympanic membrane were studied using intact, fresh or dried tympanic membrane attached to external auditory meatus. However, physical property, proper elasticity-Young Modulus, of the tympanic membrane has not been clarified yet. Present study is attempted to further clarify proper Young Modulus of tympanic membrane, and to distinguish possible difference between layer of stratum radiatum and layer of stratum circulare of tympanic membrane in breaking tension and in Young Modulus. Tympanic membrane was excised from sacrificed dog, and preparation was made into the size of approximately 1 mm in width and 3 mm in length. In fresh or dried tympanic membrane, which was dried at $80^{\circ}C$ for 24 hrs., some preparations were made along the long axis parallel to the fibers of radial direction, and others were made along the long axis perpendicular to the radial fibers-circular direction. Breaking tension and displacement according to loading, were measured and Young Modulus was calculated in tympanic membrane preparations under the different experimental conditions. Results obtained are summarized as follows : 1. Young Modulus of fresh tympanic membrane in radial direction was $6.57{\times}10^8\;dyne/cm^2$, and that of fresh preparation in circular direction was $1.68{\times}10^8\;dyne/cm^2$. The Young Modulus of fresh tympanic membrane in radial direction resembles to that of silk and whale moustache. In dried tympanic membrane, Young Modulus of preparation of radial direction was $30.2{\times}10^8\;dyne/cm^2$ and that of preparation in circular direction was $25.0{\times}10^8\;dyne/cm^2$. 2. Breaking tension of fresh tympanic membrane was 44.9 gm/mm in radial preparation, and 7.9 gm/mm in circular preparation. In dried tympanic membrane, breaking tension was 46.7 gm/mm in preparation of radial direction, and 17.2 gm/mm in preparation of circular direction. 3. Much smaller breaking tension of the circular preparation-one fifth to the radial preparation-seemed to be responsible for the higher incidence of circular fiber breaking in tympanic membrane performation caused by trauma or sudden change in atmospheric pressure. 4. The correlation seemed to be very close between breaking tension and Young Modulus in tympanic membrane.

• Membrane Journal
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• v.15 no.2
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• pp.85-104
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• 2005

Recently, membrane can be prepared by two methods, phase inversion and electrospinning techniques. Phase inversion technique is a conventional but commercially preparation membrane. The most versatile of preparation in this technique is immersion of the cast film into nonsolvent bath, causing dense top layer with a finger-like pattern in the sub layer membrane. The membrane pore size getting from phase inversion is in the range of micro or submicrometer. As a result, it can be used as microfiltration and ultrafiltration applications. A new technique, electrospinning, is introduced for membrane preparation. Nonwoven nanofibrous mat or nanofibrous membrane is obtained. In this technique, electrostatic charge is introduced to the solution jet, causing a thin fiber with high surface area; hence it can be used in the applications where high surface area-to-volume or length-to-diameter ratios are required. Moreover, the pore size can be controlled by controlling the time of electrospinning. Hence, it can be used as a filter for filtering microparticles as well as nanoparticles.

• Membrane and Water Treatment
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• v.13 no.4
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• pp.191-199
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• 2022

In industrial production, the development of traditional polyamide nanofiltration (NF) membrane was limited due to its poor oxidation resistance, complex preparation process and high cost. In this study, a composite NF membrane with high flux, high separation performance, high oxidation resistance and simple process preparation was prepared by the method of dilute solution dip coating. And the sulfonated polysulfone was used for dip coating. The results indicated that the concentration of glycerin, the pore size of the based membrane, the composition of the coating solution, and the post-treatment process had important effects on the structure and performance of the composite NF membrane. The composite NF membrane prepared without glycerol protecting based membrane had a low flux, when the concentration of glycerin increased from 5% to 15%, the pure water flux of the composite NF membrane increased from 46.4 LMH to 108.2 LMH, and the salt rejection rate did not change much. By optimizing the coating system, the rejection rate of Na₂SO₄ and PEG1000 was higher than 90%, the pure water flux was higher than 40 LMH (60psi), and it can withstand 20,000 ppm.h NaClO solution cleaning. When the post treatment processes was adjusted, the salt rejection rate of NaCl solution (250 ppm) reached 45.5%, and the flux reached 62.2 LMH.

• Membrane and Water Treatment
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• v.13 no.3
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• pp.139-145
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• 2022

Development in advanced separation processes leads to the significant advancement in polymeric membrane preparation methodology. Therefore, present research investigated the preparation and characterization of cellulose acetate membrane by phase inversion separation method to determine optimized operating parameters. Prepared CA membrane's performance was been analyzed in terms of % rejection and flux. Investigation was conducted to study effect of different parameters such as polymer concentration, evaporation rate, thickness of film, coagulation bath properties, temperature of polymer solution and of the coagulation bath etc. CA membrane was fabricated by taking polymer concentration 10wt% and 11wt% with zero second evaporation time and varying film thickness over non-woven polyester fabric. Effect of coagulation bath temperature (CBT) and casting solution temperature were also been studied. The experimental results from SEM showed that the surface morphology had been changed with polymer r concentration, coagulation bath and casting solution temperature, etc. Lower polymer concentration leads to lower precipitation time giving porous membrane. The prepared membrane was tested for advanced waste water treatment of relevant effluent stream in pilot plant to study flux and rejection behavior of the membrane.

• Proceedings of the Membrane Society of Korea Conference
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• 2002.05a
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• pp.90-93
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• 2002

• Membrane Journal
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• v.20 no.4
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• pp.320-325
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• 2010

This paper was carried out to study the preparation condition and the permeation flux of reinforced poly(vinylidene fluoride) (PVDF) hollow fiber microfiltration (MF) membrane with the solvent, additive, second miscible polymer, and preparation condition used poly(vinylidene fluoride) (PVDF) such as a material with the excellent chemical stability and the milder preparation condition. The performance of the reinforced MF membrane prepared obtained the average $0.3{\mu}m$ pore size, $42kg_f/cm^2$ tensile strength, and the high water flux of 600 LMH. The change of membrane performance with various additives was considerably affected on the water flux and rejection. For hydrophilic modification of hydrophobic PVDF MF membrane, the MF membrane might be prepared with a prefer water flux and rejection by addition of hydrophilic poly(methyl methacrylate) (PMMA).

• Proceedings of the Membrane Society of Korea Conference
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• 2003.05a
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• pp.75-78
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• 2003

• Proceedings of the Membrane Society of Korea Conference
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• 1999.10b
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• pp.71-73
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• 1999

• Proceedings of the Membrane Society of Korea Conference
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• 2001.11a
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• pp.31-33
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• 2001