• Proceedings of the Korean Fiber Society Conference
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• 1996.10a
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• pp.478-483
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• 1996

다관능성 에폭사이드 PPE(Polyglycerol Polyglycidyl Ether)를 양모섬유에 처리하였을 때 부가반응의 특성을 고찰하였다. 에폭사이드 PPE에 의한 부가반응이 촉매작용을 하는 NaSCN 존재하에서 이관능성 EGDE보다 높은 부가율을 얻을 수 있었다. 에폭사이드 부가반응은 고온에서 반응이 잘 일어나며 에폭사이드 처리욕의 pH는 반응 초기 급격히 상승했다가 이후 점차 초기 값까지 안정화된다. 처리한 양모섬유를 FTIR의 KBr-pellet법과 ATR법에 의해 분석하여 absorbance ratio를 비교하였을 때 부가반응은 표면으로의 그라프트 반응이 우세함을 알 수 있었으며 이러한 결과는 SEM 관측을 통하여 확인할 수 있었다. Performic acid/Ammonia solubility를 에폭사이드 처리 양모섬유에 적용하여 용해도 변화를 보았을 때 부가된 양이 많을수록 용해도 값이 감소하며 특히 15.6%를 중심으로 용해도 변화가 둔화되었다. 아미노산 분석으로 에폭사이드가 반응한 아미노산이 cystine임을 알 수 있었으며 단백질 사슬간에 가교반응이 이루어졌음을 확인할 수 있었다.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.519-533
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• 2010

Activity oefficients and solubilities of L-Alanine in aqueous solutions containing each of four electrolytes(NaCl, KCl, $NaNO_3$ and $KNO_3$) were measured at 298.15 K. The measurements of activity coefficients were carried out in the electrochemical cell coupled with two ion-selective electrodes(cation and anion), and the solubilities were measured by the gravimetric analysis of saturated solutions in equilibrium with the solid phase of L-alanine. To model the activity coefficients and solubilities of amino acid in the amino acid/electrolyte aqueous solutions, thermodynamic relations of the residual Helmholtz free energy in the amino acid/electrolyte aqueous solutions were developed based on the perturbed-chain statistical associating fluid theory(PC-SAFT) combined with the primitive mean spherical approximation(primitive-MSA). In the present model, it is assumed that the zwitterions of L-alanine are associated with each other and cross-associated with water molecules, and also cross-associated with the cation and anion dissociated from an electrolyte(inorganic salt). The activity coefficients and solubilities of L-Alanine calculated from the theoretical model proposed in this work are found to be well agreeable with experimental data.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.203-210
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• 2000

The preparative methods of a chitosan-deposited activated carbon and its characteristics were studied by using three kinds of chitosan with different degree of deacetylation and average molecular weight. The procedure was consisted of the dissolution of chitosan into acid solution, impregnation of activated carbon, agitation, evaporation, and drying. When the chitosan-dissolved acid and its concentration, amounts of chitosan deposited, and agitation conditions were changed, the specific surface area, deposition state on surface, and stability were investigated, and amounts of Cr(VI) adsorbed was measured. In the preparation process, it was proper to agitate the chitosan-dissolved acetic acid solution at room temperature for 1hr. In the deposition of chitosan with low molecular weight, the specific surface area of activated carbon was greatly decreased even at low chitosan loading, but in the case of high molecular weight it was not nearly changed to 10wt% loading. It was known that chitosan was uniformly and physically deposited on activated carbon. The chitosan-deposited activated carbon was stable into the solution over about pH 6. The removal of Cr(VI) was remarkably enhanced by adding the adsorption function of chitosan to the surface of activated carbon with about 5wt% chitosan. It may be therefore used as an adsorbent for removing the pollutants in air and wastewater.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.705-708
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• 2001

Enzymatic synthesis and purification of sugar esters using supercritical $CO_2$ were investigated. The observed yield of suagr ester produced by transesterification of methyl glucoside and oleic acid using a lipase(Novozym 435) was 67% at 24 hours of reaction in the supercritical $CO_2$. The solubility of the fatty acids in the supercritical $CO_2$ was measured to find the conditions of supercritical separation of the fatty acids from the reaction mixture. The solubility of capric and oleic acid was 5 ${\times}$ $10^{-4}$, 1.7 ${\times}$ $10^{-4}$ mol/mol $CO_2$, respectively, varying at $35{\sim}50^{\circ}C$ and 80${\sim}$120 atm.

• Clean Technology
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• v.11 no.2
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• pp.105-116
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• 2005

Carboxymethylcellulose(CMC) which is water soluble at room temperature was manufactured from the cellulose material in this study. Experimental parameters were reaction temperature, time and concentration of NaOH and monochloroacetic acid. CMC was tested for solubility, degree of substitution(D.S.) and tensile strength. The surface structure of CMC fiber was tested using scanning electron microscope(SEM). CMC manufactured from viscose rayon was affected by the chemical concentration rather then the reaction time and temperature. Also, degree of substitution is closely related to the solubility of the CMC.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.04a
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• pp.65-66
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• 1996

투과증발법은 상부에 액체공급액이 반투과막과 접촉하고 있고 하부에 진공에 가까운 낮은 압력을 걸어줌으로써 투과물이 수증기로 제거되는 막공정의 하나이다. 막을 통한 분리는 혼합물의 각 성분이 막내에서 다른 용해도와 확산도를 가지고 있기 때문에 발생한다. 이 공정의 지배적인 전달 메카니즘은 용해-확산 모델을 기초로 하고 있기 때문에 전형적으로 투과증발막은 대개 미세다공성 지지체에 얇은 선택성을 가진 재료를 입힌 복합막을 사용한다. 본 연구의 목적은 선택성을 가진 상부층막이 키토산인 복합막에서 지지체 구조의 영향을 살펴보고 키토산 복합막에 대한 물-에탄올 분리에 대해 최적의 모델을 찾는 것이다. 투과증발막소재로서의 키토산은 친수성기를 가지고 있으므로 물과 알코올의 분리에서 물만을 선택적으로 흡수하여 투과시키는 우수한 성능을 지니고 있으나 더욱 효과적인 막성능을 발휘하기 위해서는 지지체의 역할 및 막성능에 영향을 끼치는 여러 가지 인자들을 고려해서 막을 설계하는 것이 필요하다. 여기서는 상부층의 막두께, 지지체의 특성, 피드 농도 등을 변화시켜 가장 적당한 모델을 예측하였다.

• Korean Journal of Food Science and Technology
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• v.54 no.1
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• pp.66-74
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• 2022

To improve the solubility of β-carotene, three types of β-carotene-loaded nanocapsules were prepared using chitosan (CS) and two cross-linkers, sodium tripolyphosphate (TPP) and hyaluronic acid (HA), alone or in combination (CS-TPP, CS-TPP-HA, and CS-HA). The entrapment efficiency of all nanocapsules significantly increased with an increase in TPP and HA, with the efficiency ranging from 95% to 99%. The solubility of β-carotene was significantly improved by CS nanoencapsulation before and after lyophilization and during storage. CS/HA nanoencapsulation significantly improved (by 11-fold) the water solubility of β-carotene. In particular, CS/HA nanoencapsulation was the most effective in terms of not only the solubility of β-carotene, but also the redispersibility ratio. Therefore, CS/HA encapsulation could be useful for improving the solubility of poorly soluble active ingredients, such as β-carotene.

• Journal of Sericultural and Entomological Science
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• v.31 no.2
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• pp.121-126
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• 1989

Two kinds of solution for the measurement of solubilities of Sericin are prepared as followings at temperature 90 deg. C. One has the total carbonate concentration as 0, 50, 100mg CO2/l prepared with non-carbonate distilled water, sodium hydrogen carbonate and 0.1N HCI and NaOH, the other has total hardness, that is, calcium hardness or magnesium hardness as 0, 20, 50, 100mg CaCO2/l respectively prepared with non-carbonate distilled water, calcium carbonate and magnesium oxide. Solubilities of Cocoon layer Sericin at above solution gives following results ; 1. pH shows little effect on the solubility of Sericin at the non-carbonate solution but at the carbonate solution pH shows a sensitive effect on the solubility of Sericin. These means that pH controls the concentration of H2CO3, HCO3-and CO32- which prevent and promote the solution of Sericin. 2. After the cocoon layer treatment at the solution, the initial pH of 4.0, 7.0, 9.0 of the solution changed to 6.0-6.5 at the lower total carbonate solution. However in the higher total carbonate solution pH did not changed very much. This may be explained by the buffer action of carbonate. 3. The effect of the hardness on the solubility of Sericin was not found in the non-carbonate solution with the standard hardness after treatment of cocoon layer.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.271-271
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• 1996

PG의 농도가 AM의 경피투과에 미치는 영향은 용해도곡선과 유수분배곡선의 교점인 40% 농도에서 투과극대를 보였다. 지방산 및 지방산 알코올의 촉진효과는 리놀레인산＞올에인산＞올레일알코올＞ DHA=EPA=라우린산의 순이었고 PG에 리놀레인산 또는 올레인산을 첨가한 경우는 PG 단독에 비해 129.9 및 43.0배의 투과를 나타냈다. 또, 리놀레인산의 농도증가 (2,5,10%)에 따라 피부/매질 간의 분배계수가 가장 큰 5% 농도의 리놀레인산을 사용했을 때 투과효과가 최대로 나타났다. 한편, AM의 농도증가에 따른 투과효과에 있어서는 포화용해상태인 2% 약물농도에서 투과 flux가 가장 컸다. 라우릴황산타트륨의 첨가는 유의성 있는 효과를 발현하지 못했고 지방산과 병용시에도 지방산 단독 사용시에 비해 오히려 투과를 감소시켰다. 종차에 따른 AM의 피부투과에 있어서는 리놀레인산을 투과촉진제로 사용한 결과 흰주와 무모마우스의 투과 flux가 각각 23.78 및 213.29 $\mu\textrm{g}$/$\textrm{cm}^2$/hr로 무모마우스가 8.97배 높았다. 흰주의 추출액 및 호모지네이트 중에서의 AM의 대사에 있어서는 겉보기 1차 분해속도정수가 표피측추출액, 장막측추출액, 호모지네이트에서 각각 0.0105, 0.572 및 6.153$hr^{-1}$로 호모지네이트 중의 분해속도가 가장 빨라 AM은 피부투과 중에 가장 많이 분해됨을 알았다.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.142-153
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• 1995

This study is undertaken to investigate proper condition and dissolution method of silk fibroin to use it functional material as powder or membrane. Silk fibroin was dissolved with calcium chloride ethanol aqueous solution and hydrochloric acid. When silk fibron was dissolved with calcium chloride ehanol aqueous solution, main chain of silk fibroin was degradaded and molecular conformation was changed. Silk fibroin powder was made from silk fibroin solution. It showed lower thermal decomposition temperature and crystallinity than those of native silk fibroin. And Its molecular conformation was random coil structure. By acid gydrolysis, main chain of silk fibroin was attacked randomly. Silk fibroin powder from hydrolysate showed high crystallinity and thermal decomposition temprature. $\beta$-form molecular conformation was found by IR and X-ray diffraction. Silk fibroin powder form dissolved part with hydrochloric acid showed low thormal decomposition temperature but high crystallinity. During acid hydrolysis, transition of molecular structure of silk fibroin occurred, and it changed to $\alpha$-helix. Silk fibroin film was achieved by casting silk fibroin solution by ehanol solution or saturated vapor treatment, and its molecular conformation changed to $\beta$structure.