• Membrane Journal
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• v.19 no.2
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• pp.104-112
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• 2009

Ultrafiltration membranes (UF) were manufactured by the conventional phase inversion method using an additives with N-methyl-2-pyrrolidinone as a solvent. Characteristics of performance could be controlled by the preparation conditions and the operating methods. The fouling resistance was observed by the relative ratio of permeate flux $(J_t)$/pure water flux $(J_o)$. Compared with the anion charged membranes and its original polyamide membrane, fouling resistance to the protein was increasing in proportion to the ion exchange capacity. The relative flux for the bovin serum albumin (BSA) solution increased as pH value further away from isoelectric point of BSA. The hydrophilicity of a membrane, the pH condition, and the operating temperature played the important role in the membrane permeations.

• Macromolecular Research
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• v.13 no.1
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• pp.39-44
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• 2005

Ion-exchange polymeric stationary phases presenting amino acid and amino groups were prepared by the surface grafting of glycidyl methacrylate onto a silica gel surface and subsequent amination. Three kinds of amino acids-L-arginine (Arg), D-lysine (Lys), and D-histine (His)-were used in this study. An ion-exchange polymeric stationary phase presenting ethylene diamine (EDA) was also prepared by surface graft polymerization. Separation of the model proteins bovine serum albumin (BSA), chick egg albumin (CEA), and hemoglobin (Hb) was performed using the amino acid- and amine-derived columns. In separating the CEA/BSA mixture, the resolution time of BSA was longer than that of CEA when using the EDA column, whereas the resolution time of BSA was shorter than that of CEA when using the Arg, Lys, and His columns. In the separation of the Hb/BSA mixture, the resolution time of BSA was longer than that of Hb in the EDA column, whereas the resolution time of BSA was shorter than that of Hb in the amino acid columns (D-Lys, L-Arg, and D-His).

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.811-815
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• 1995

Effect of deamidation with Neutrase on the solubility of bovin serum albumin(BSA), egg albumin(EA), soy protein isolate(SPI) was investigated. Solubility of deamidated BSA in distilled water was decreased from 98% to 83% against native BSA at pH 4~8, minimum solubility of deamidated BSA was pH 6. Solubilities of native BSA and deamidated BSA in 0.2M NaCl solution were shown 100% as compared greately decreasing both solubilities in 1.0M NaCl at acidic pH. According to deamidation, solubility of EA in distilled water was increased below pH 4 and above pH 6, while solubility of EA in NaCl solution was decreased by deamidation at acidic pH. Solubility of SPI in distilled water was greately increased by deamidation at overall pH, deamidation was increased solubility in NaCl solution above pH 5. There was, however, no difference on solubility by deamidation below pH 5.

• Membrane Journal
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• v.24 no.4
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• pp.276-284
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• 2014

In this study, a hydrophobic polyvinylidene fluoride (PVDF) membrane was modified by coating neutral hydrophilic poly(vinyl alcohol). The flux of pure water was measured and then fouling test was conducted with bovin serum albumin (BSA) as model protein foulant. As a result, the experiments showed that pure water flux was decreased but anti-fouling property was significantly enhanced. Pure water flux with increasing molecular weights of the polymer was decreased and fouling resistance was enhanced. Also, Pure water flux with increasing solution concentration was decreased and fouling resistance was enhanced. It is probably due to the increase in hydrophilicity and decrease in roughness of the membrane surface, as revealed by contact angle and AFM analysis.

• Membrane Journal
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• v.14 no.1
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• pp.26-36
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• 2004

Ultrafiltration membranes based on anion charged poly(bis[4-(3-aminophenoxy)phenyl]sulfone pyromellite) imide derivatives (ACPI) were prepared by the phase inversion method. The polymers have good solubility in aprotic polar solvents. The composition of casting solution and the casting conditions played an important role in determining the permeation characteristics of membrane because the membrane structure could be controlled by the preparation conditions. The extent of fouling-repression was observed by the relative ratio of permeate flux ($J_t$)/pure water flux ($J_0$) and the membrane filtration index (MFI). The characteristics were measured by aqueous solution of bovine serum albumin (BSA) over a pH range of 2.5-9.0. The ACPI membrane having a hydrophilic property was less fouled than the membrane prepared from the original polyimide. With increasing the ion exchange capacity of ACPI membrane, th $\varepsilon$ relative ratio of flux was higher while the membrane filtration index was lower as compared with the original polyimide membrane. From the further away from isoelectric point of bovin serum albumin, the permeation was higher as well as the formation of fouling was more diminish. ACPI membranes having various their properties could be obtained. Further, it was proved that their permeation properties could be determined from the preparation conditions, various operating conditions, and dim $\varepsilon$ rent ion exchange capacity of anion charged polyimide derivatives.

• Membrane Journal
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• v.18 no.3
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• pp.214-218
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• 2008

Protain affinity membranes based on PES-BSA was preapared by the electrospinning method. The process problem caused by the electrospining was solved by using HFB having high solubility and boiling point. It was expecting that the mass production of protein affinity membrane would be possible with broad range of optimized temperature and humidity. BSA in the PES nanofiber was confirmed by the color change from colorless to violet during the biuret test. The buffer solution with DMSO showed that the amount of elution was 5 times higher than the one when the buffer solution without DMSO was used. This is due to the restriction effect of DMSO on the dissociation of L-tryptophan from BSA during the washing step.

• Membrane Journal
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• v.18 no.4
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• pp.306-316
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• 2008

The adsorption characteristics of L-tryptophan of PES-BSA affinity membranes prepared by using electro-spinning were investigated. It was found that the fiber diameters could be controlled by the comparisons of fiber diameters prepared by various spinning conditions through FESEM and Image Analyzer. Darcy's permeability constants, mechanical properties and hydrophobic properties were enhanced since micro-fibers increased by increasing the composition ratio of HFB and BSA. The elution capacity of L-tryptophan in borate-DMSO buffer solution was higher than that in tris-HCl buffer solution, while the elution capacity of A 7906 type BSA was higher than A 8022 type BSA. This is due to the characteristics of BSA type, i. e. higher purity and uniform molecular weight and better pH stability of A 7906 type BSA than those of A 8022 type BSA.