• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.814-819
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• 2015

The natural crosslinking agent genipin has been applied widely in biomedicines and foods nowadays. Because of the special hemiacetal ring structure in its molecule, it can only be prepared by hydrolysis of geniposide according to biocatalysis. In this research, strategies including aqueous-organic biphasic catalysis and substrate fed-batch mode were adopted to improve the biocatalysis process of genipin. A 10 L ethyl acetate-aqueous biphasic system with geniposide fed-batch led to a satisfying genipin yield. With Fusarium solani ACCC 36223, 15.7 g/l genipin in the ethyl acetate phase was obtained, corresponding to space-time yields of 0.654 g l^-1 h^-1.

• 폴리머
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• 제35권1호
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• pp.72-76
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• 2011

폴리(비닐 알코올)(PVA)의 수분 팽윤성 조절을 위하여 천연 색소 기교제로 PVA를 가교한 후, 이들의 물성을 화학 가교된 PVA와 함께 비교하였다. 천연 가교제로 사용된 안토시아닌 그리고 크로신에 함유된 하이드록시기는 NaCl 촉매 하에서 PVA의 하이드록시기와 수소 결합하여 PVA를 물리적으로 가교시킴을 알 수 있었다. 화학 가교제인 Polycup 172에 의하여 가교된 PVA와 비교하여 수분 팽윤성이 현저히 감소하며 또한 가교에 의한 결정화도가 감소함을 확인하였다. 천연 가교제로 가교된 PVA는 화학 가교된 PVA에 비하여 상대적으로 열안정성이 떨어지나 함유된 다당류에도 불구하고 순수 PVA보다는 높은 열안정성을 가짐을 알 수 있었다.

• 한국염색가공학회지
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• 제2권2호
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• pp.14-19
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• 1990

The setting behavior of disulfide-enriched wool and disulfide-crosslinked silk obtained by treatment with a disulfide-containing crosslinking agent, bis $(\beta-isocyanatoethyl)$ dissulfide was compared with that of untreated wool and silk under the absence and the presence of a reducing agent. Rearrangment of secondary bonds facilitated by cleavage of crosslinks as well as rearrangement of crosslinks itself seems to play an important role in the set stability.

• 한국의류산업학회지
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• 제10권2호
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• pp.260-266
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• 2008

Recently there has been a growing interest in the use of natural dyes in textile applications. Natural dyes can exhibit better biodegradability and generally have a higher compatibility with the environment. In this study, the colorants of clove were extracted with boiling water. Chitosan crosslinked cotton fabrics have been dyed with aqueous extract of clove and their dyeabilities on the fabrics were studied. Additionally the fastness to washing and light, and the effects on antimicrobial properties were also investigated. Cotton fabrics were treated with a crosslinking agent epichlorohydrin in the presence of chitosan to provide the cotton fabrics the dyeing properties of natural dye(clove) by the chemical linking of chitosan to the cellulose structure. This process was applied by means of the conventional mercerizing process. The chitosan finishing and durable press finishing of the cotton fabrics occurred simultaneously in the mercerization bath. The dyeability(K/S), which was obtained by CCM observation, remarkablely became increased when the crosslinked chitosan concentration was higher. The hue value indicated reddish yellow with increasing the crosslinked chitosan concentration. And the color fastness to washing and light was the almost the same. The chitosan treated cotton fabrics showed very high activities with almost 100% reduction.

• 한국염색가공학회지
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• 제20권3호
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• pp.8-17
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• 2008

For the purpose of standardization and practicability of natural dyeing, the mordanting and dyeing properties of turmeric was studied. In this study, the colorants of turmeric were extracted with boiling water. Chitosan-crosslinked cotton fabrics was dyed with aqueous extract of turmeric and their dyeabilities on the fabrics were studied. Additionally the fastness to washing and light were also investigated. Cotton fabrics were treated with a crosslinking agent epichlorohydrin in the presence of chitosan to provide the cotton fabrics the dyeing properties of natural dye(turmeric) by the chemical linking of chitosan to the cellulose structure. The chitosan finishing and durable press finishing of the cotton fabrics occurred simultaneously in the mercerization bath. The dyeability(K/S), which was obtained by CCM observation, remarkably became increased when the crosslinked chitosan concentration was higher. Dyeability of turmeric was improved on chitosan-crosslinked cotton fabric rather than only cotton fabric, while the saturated dyeing time was 20minutes at $60^{\circ}C$. The hue value indicated greenish yellow with increasing the crosslinked chitosan concentration. And the color fastness to washing and light was almost the same.

• Elastomers and Composites
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• 제35권4호
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• pp.303-310
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• 2000

가황천연고무를 제조할 때 가교제와 여러 첨가제의 배합비를 조절하여 그 배합비가 제품의 저온 회복력에 미치는 영향을 검토하였다. 가황천연고무를 200% 신장시킨 후 $-40^{\circ}C$에서 24시간 유지시켜 복원력을 관찰하였다. 일정한 범위에서 황의 함량이 높아질수록, 또한 충전제의 함량은 적을수록 저온회복율은 향상되었다. 가황촉진제, 가소제와 가황촉진조제 등은 일정함량에서 최고치를 나타내었다. 과산화물을 약간 침가하였을 때 저온회복율은 보다 향상되었으나 가황시간은 보다 길어졌다. 최대의 복원력은 85%를 얻을 수 있었다.

• 한국의류산업학회지
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• 제10권3호
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• pp.377-384
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• 2008

For the purpose of standardization and practicability of natural dyeing, the mordanting and dyeing properties of gallnut was studied. In this study, the colorants of gallnut were extracted with boiling water. Chitosan crosslinked cotton fabrics were been dyed with aqueous extract of gallnut and their dyeabilities on the fabrics were studied. Additionally, the fastness to washing and light were also investigated. Cotton fabrics were treated with a crosslinking agent epichlorohydrin in the presence of chitosan to provide the cotton fabrics the dyeing properties of natural dye(gallnut) by the chemical linking of chitosan to the cellulose structure. The chitosan finishing and durable press finishing of the cotton fabrics carried out simultaneously in the mercerization bath. The dyeability(K/S), which was obtained by CCM observation, remarkably increased as the concentration of chitosan was high. Dye ability of gallnut showed higher toward chitosan treated cotton than controlled cotton fabric under condition at $60^{\circ}C$, for 20 min. The hue value indicated reddish yellow with increasing the crosslinked chitosan concentration. And the color fastness to washing and light was the almost the same.

• 한국응용과학기술학회지
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• 제29권1호
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• pp.13-18
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• 2012

금속 주조시 사용되는 탄소이형제를 카본블랙과 점증제 겸 알데하이드 화합물의 경화제로 사용될 수 있는 수용성 고분자인 잔탄검(X-gum), 카르복시메틸셀룰로오스(CMC)을 혼합하여 제조하였다. 이 때 카본블랙의 안정한 분산을 위하여 0.25 wt%의 X-gum 또는 1.0 wt%의 CMC가 적당하였다. 1.0 wt% 보다 낮은 농도의 CMC를 사용했을 경우 카본블랙이 매우 쉽게 층분리되었다. 유리판에 대한 부착력은 경화제와, 구르탈알데하이드 및 사슬연장제인 올리고당의 양에 비례하였으며. X-gum으로 제조된 탄소 이형제는 CMC를 이용해 제조된 것보다 유리에 대한 부착력이 우수하였다. 결과적으로 본 실험의 최적 조건에서 제조된 탄소이형제는 친환경적으로 주조시에 적용할 수 있을 것으로 판단된다.

• 접착 및 계면
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• 제9권2호
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• pp.8-15
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• 2008

마이크로캡슐은 다양한 기능성 물질의 약물 전달 시스템으로서 화장품과 제약 분야에서 널리 적용되고 있다. 키토산은 천연에 풍부하게 존재하는 생체고분자로 생체적합성이 우수하며 무독성이다. 본 연구에서는 키토산 마이크로캡슐을 글루타르알데히드를 가교제로 사용하여 W/O 형태의 유화법으로 제조하였다. 유화제로는 span80을 사용하였으며 가교가 시행되는 bath상의 물질은 mineral oil을 사용하였다. 제조된 키토산 마이크로캡슐은 완벽한 구의 형태로 평균 $2{\sim}10{\mu}m$ 크기를 보였으며, 교반속도와 유화제의 농도에 따른 캡슐의 직경 및 형태 변화를 관찰하였다. 마이크로캡슐의 방출실험을 하기 위하여 가교제, 키토산, 그리고 유화제의 양을 변화시키면서 방출 속도를 측정하였다. Riboflavin의 방출속도는 키토산의 가교 정도와 사용한 유화제의 양에 따라 크게 변하였다.

• Journal of Chest Surgery
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• 제44권3호
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• pp.197-207
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• 2011

Background: In cardiac surgery, especially in the reconstruction of vascular structures and intracardiac defects, glutaraldehyde has usually been used as the reagent for fixing porcine or bovine pericardial tissues. But the well-known problem of calcification or cytotoxicity of glutaraldehyde motivates the search for a replacement. The aim of this study is to investigate the physical, mechanical, and biochemical characteristics of bovine pericardial tissues fixed with genipin, which is known to be a less toxic and more natural fixing reagent. Materials and Methods: Bovine pericardial tissues were fixed with different concentrations and conditions of glutaraldehyde and genipin. To determine the physical, mechanical, and biochemical differences among different concentrations and conditions, we divided the tissue into 18 groups by concentration, the addition of organic solvents, and the timing of adding the organic solvents, and compared the characteristics of each group. Results: Tensile strength, physical activity, and thermal stability tests revealed that the tissues fixed with glutaraldehyde were better with regard to mechanical strength and biochemical durability. However, the difference was not significant statistically. Conclusion: Genipin can be used as an alternative crosslinking agent for pericardial tissue, considering given its physical, mechanical, biochemical characteristics and low cytotoxicity comparable to glutaraldehyde. However, further studies are needed on the immune reaction and the long term changes in genipin-fixed tissues in the human body.