• Journal of the Korean Chemical Society
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• v.28 no.6
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• pp.393-398
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• 1984

Porphyrin-rich materials were obtained from some crude asphalts by gel permeation chromatography and silica gel chromatography. After extraction of each chromatographic fractions through alumina with pyridine, more concentrated metalloporphyrins were obtained. Demetallation of metalloporphyrins was possible without destroying porphyrin ring to provide different type of metal free porphyrins.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.361-370
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• 1988

To investigate the interaction between whey and soybean protein, thermal changes of component proteins were analyzed by column chromatography and gel electrophoresis. In the Sephadex G-200 chromatography of the mixture treated at above $80^{\circ}C$, the amount of low molecular weight proteins and high molecular aggregates were increased. This implicated that dissociation of 1ls globulin into subunits and the formation of soluble aggregates between these subunits and whey proteins that contain thiol and disulfide groups. These interaction between soy proteins and ${\beta}-lactoglobulin$, ${\alpha}-lactalbumin$, and proteose-peptone 3 were confirmed by gel electrophoresis. Bovine serum albumin, Immunoglobulin-G(H), Lactoferrin, 1ls-subunits(basic and acidic), and subunit of 7s globulin were also considered to interact each other depending on the condition of the salt solutions.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.206-209
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• 2008

The modified supercritical water treatment method is adopted for hydrolysis of wood powder, Populus alba$\times$glandulosa. This modified method is containing 0.05% HCl or $HNO_3$ as acid catalyst. The supercritical water treatment(SCW) was performed for 1 min. with $350^{\circ}C$, $380^{\circ}C$, $400^{\circ}C$ and $425^{\circ}C$, respectively, under 230 $\pm$ 10 atm using continuous flow system. When acid was added to powder prepared for SCW treatment, the yields of monomeric sugars were significantly increased. The lignin remained after supercritical treatment was applied to gel permeation chromatography(GPC) for molecular weight distribution analysis. Compared to the lignin produced from SCW treatment without acid catalyst, the average molecular weight of lignin compounds treated with acid was clearly decreased. Particularly, Mn/Mw ratio is decreased. This result shows supercritical water treatment of wood powder can change the molecular weight of lignin to small size. However, it is necessary to be further studied for exactly characterizing the lignin produced from supercritical water treatment.

• The Korean Journal of Rheology
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• v.10 no.3
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• pp.137-142
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• 1998

유변물성 자료로부터 고분자의 다분산성을 예측하는 방법은 신속한 중합반응 공정 제어를 위해서 중요한 연구분야중 하나이다. 본 연구에서는 다양한 분자량과 분자량 분포를 가진 폴리에틸렌에 대한 Shroff와 macridis 가 제시한 다분산성 매개변수 ER과 ET를 구하 고 겔투과 크로마토그래피에서 얻은 Mw/Mn과의 상관관계를 조상하였다. Mw/Mn과 비례적 인 상관관계를 보여주었으나 ET는 상관성이 없는 것으로 나타났다. ER값에는 분자량 분포 도 외에 LCB의영향도 큰 것으로 나타났다. 또한 분자량 분포중에서 고분자량 부분의 미미 한 변화에도 ER이 크게 변해 GPC보다 다분산성의 변화를 더 민감하게 예측할수 있음을 알 수있었다.

• Journal of the Korean Vacuum Society
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• v.6 no.3
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• pp.213-219
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• 1997

The plasma polymerized styrene films were prepared by using an inter-electrode capacitively coupled gas-flow-type reactor, and the effects of plasma polymerization condition on the molecular weight distribution were investigated by Fourier Transform Infrared (FT-IR), Pyrolysis Gas Chromatography(PyGC), Differential Scanning Calorimetry(DSC) and Gel Permeation Chromatography(GPC). From the above results, the very cross-linked films different from chemical characteristics of the starting monomer were taken out, and it is realized that the molecular structure, cross linking density, and molecular weight distribution could be controlled by changing the parameters such as deposition pressure, deposition power and gas flow rate. Accordingly, it is suggested that plasma polymerization method performed by inter-electrode capacitively coupled gas-flow-type reactor has good characteristics for manufacturing the functional organic thin films which can be applied in sensors, opto-electric device, photo-resist by changing the polymerization parameters.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.458-464
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• 1999

The value of lysozyme as a natural food preservative is continuously increased due to its unique antimicrobial activity. To determine the optimum separation concentration among the various hen egg white protein (HEWP) concentrations (0.25, 0.5, 1.0, w/v), protein concentrations, lysozyme concentrations, specific activities (SA), and purification factors of prefiltered solution (PFS) and PM30 permeate solution (PMS) were compared. The purity of lysozyme separated at each step was analyzed and confirmed by gel permeation chromatography and electrophoresis. The fouling deposits on membrane were observed by SEM. The non-enzymatic proteins were removed over 99% by ultrafiltration (UF). The increased feed concentration did not contribute to the increase of SA. SA of PMS was 18 to 31 times higher than that of PFS. The optimum feed concentration was decided as 0.25% based on SA and purification factor. The non-enzymatic region of gel chromatogram was proved to be ovalbumin. The thickness of deposit on the UF membrane was approximately $0.9{\mu}m$ and removed by cleaning with 0.1 N NaOH. Therefore, UF using PM30 membrane was very effective to separate the antimicrobial lysozyme from various HEWPs.

• Polymer(Korea)
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• v.25 no.1
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• pp.33-40
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• 2001

Fluorinated polyurethane elastomers were synthesized by two step polyaddition of a perfluorinated polyether diol(trade name of Fomblin $ZDOL^{\circledR}$) and diisocyanates such as 4,4'-diphenyl methane diisocyanate(MDI) and toluene 2,4-diisocyanate(TDI). In order to control the Fomblin moiety of the soft segment in the synthesized elastomers to 10~50%, polyether type polyols such as polypropylene glycol(PPG) and polytetramethylene glycol(PTMG) were mixed during the polymerization reaction. Ethylene diamine or 1,4-butane diol was used as chain extenders. The structure and average molecular weight of the produced polyurethanes were confirmed by using FT-IR, $^1H-NMR$, DSC, and GPC. The surface properties were analyzed by using X-ray photoelectron spectroscopy(XPS) and contact angle meter. From the results of the surface analysis it was concluded that the fluorine groups were localized on the surface rather than the inside of the polyurethane films.

• Applied Chemistry for Engineering
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• v.2 no.2
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• pp.185-191
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• 1991

The chemical composition and characteristics of the source rock collected from Dolgorae-1 well in Korea continental shelf block VI( $35^{\circ}$ 18'N.L., $130^{\circ}$ 28'E) have been investigated. An oil show analyzer(OSA) has been used to determine the contents of gas, oil and total organic carbon(TOC). The average TOC value for the sample is found to be 0.59%. The OSA has also provided hydrogen index and $T_{max}$, the maximum temperature which generate maximum hydrocarbons from kerogen. From a $T_{max}$-hydrogen index diagram the type of organic matter in the source rock was estimated to be type III kerogen. The content of bitumen and its molecular weight have been determined by means of extraction method and gel permeation chromatograph, respectively. The physicochemical properties has been studied using X-ray diffraction spectrometer, IR spectrometer and thermogravimetric method. On the basis of the results obtained in the present work, the samples collected from Dolgorae-1 well are evaluated to be poor source rocks.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.417-426
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• 1997

Rice bran protein hydrolysates were prepared and some of their physicochemical properties were investigated to utilize rice bran as starting material for functional food ingredient. Rice bran proteins (RBP) were prepared from defatted rice bran by alkaline extraction and isoelectric precipitation. The enzyme for hydrolysis of RBP was selected through measuring relative activity by pH-drop method and comparing the degree of hydrolysis (DH) of hydrolysates. The enzymatic hydrolysates prepared by $Esperase^{\circledR}$ treatment were partitioned into two fractions by ultrafiltration(UF) with a 10 kDa molecular weight cut-off membrane. Each fraction was applied to a cholic acid-conjugated ${\omega}-aminohexyl$ Sepharose 4B column and the bile acid-binding components were obtained by eluting with deoxycholate. Gel permeation chromatography on a Sephadex G-50 column revealed that molecular weight of the bile acid-binding fraction of UF permeate was distributed in ranges of $2\;kDa{\sim}10\;kDa$ and $0.2\;kDa{\sim}0.6\;kDa$. Three peaks (R-1, R-2 and R-3) were obtained by prep-HPLC of bile acid-binding fraction of UF retentate and analyzed for total and free amino acid composition. The results showed that proline content of the bile-acid binding polypeptides and peptides was four times as much as that of rice bran protein and that the peak corresponding to higher average hydrophobicity had a higher free amino acid content. Average hydrophobicity slightly increased with enzymatic hydrolysis.