• Journal of the Korean Wood Science and Technology
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• 제27권1호
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• pp.18-23
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• 1999

3회축을 갖는 Na-cellulose II의 형성조건을 X선회절법을 이용하여 검토하였다. 그 결과 Na-cellulose II는 Na-cellulose I 을 거쳐서 형성되며 결정중의 알칼리농도가 Na-cellulose I 이나 III보다 높은 조건에서 형성되는 것으로 생각되었다. 2회축에서 3회축으로의 섬유주기의 급격한 변화는 알칼리 처리 후의 수분제거방법에 의해 크게 영향받는 것으로 생각되었다. 동(銅)-알칼리셀룰로오스 복합체의 결정은 팽윤상태에서 안정된 구조를 가지며 건조에 의해 결정구조가 변화되었다.

• Journal of the Korean Wood Science and Technology
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• 제24권3호
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• pp.72-79
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• 1996

Cellulose I에서 Cellulose II로의 결정변태기구를 X선 및 전자선 회절법과 현미경적 방법을 이용하여 구명하였다. X선 회절 결과, Na-cellulose I을 고온에서 수세할 경우 Cellulose I과 Cellulose II의 혼합형 회절도가, 저온에서 수세할 경우 Na-cellulose IV의 회절도가 얻어졌다. 전자선회절 결과, 고온수세의 시료는 Cellulose I과 Cellulose II의 혼합형이 저온수세의 시료는 Cellulose II의 회절도가 얻어졌다. 또한 고온수세 시료의 전자선회절도로부터 섬유벽의 내측부가 외측부보다 재생 Cellulose I의 양이 많은 것이 확인되었다. 따라서 알칼리 팽윤시 섬유벽내에는 불완전한 팽윤이 발생하는데 그 정도는 내측부가 더욱 심한 것으로 생각된다. 이때 형성되는 불완전한 Na-cellulose I 은 고온 수세의 경우는 탈수에 의해 Cellulose I로, 저온수세의 경우는 수화에 의해 Cellulose II로 변태되지만 완전히 팽윤된 Na-cellulose I은 Cellulose I로 재생될 수 없는 것으로 생각된다. 현미경적 실험결과, mercerization과정에서 cellulose 분자쇄의 packing이나 conformation의 변화와 관련하여 microfibril 의 흐트러짐은 발생하지 않는 것으로 생각되었다.

• Journal of the Korean Wood Science and Technology
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• 제23권3호
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• pp.1-7
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• 1995

The crystal transformation from cellulose I to cellulose II during alkaline swelling of waste wood, which has been used for cultivating oak mushroom(Cortinellus edodes (Berk.) Ito et Imai), was investigated and compared to that of normal wood by a series of X-ray diffraction analysis. When the sapwood of cultivated wood was treated with 20% NaOH solution for 2 hours, the cellulose I can be easily transformed into Na-cellulose I than normal wood or heartwood of cultivated wood. Certainly the formation of Na-cellulose in wood is proportional to alkali swelling duration, and the formation of cultivated sapwood was faster than that of the other woods. Cellulose I in the sapwood of cultivated wood was easily transformed into cellulose II during mercerization, but the sapwood of normal wood and the heartwood of cultivated wood hardly converted to cellulose II. Namely, most of Na-cellulose I in normal wood can be reconverted to cellulose I in the process of washing and drying. Therefore, it can be concluded from this study that in cell wall lignin and hemicellulose can prevent the alkaline swelling of cellulose in wood and the transformation from cellulose I to cellulose II as well.

• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.1-7
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• 2003

The phase transformation from cellulose I into cellulose II in woods by way of Na-cellulose I was examined by x-ray diffraction analysis.The formation of Na-cellulose I in woods increased with the increase of treating time in alkali solution. When compression wood was treated with 20% NaOH solution at room temperature for 1 day, the x-ray diagram showed only Na-cellulose I. On the other hand, the x-ray diagram of tension wood showed a mixture of cellulose I and Na-cellulose I. Cellulose I of tension wood could not be transformed completely into Na-cellulose I even after 10-day treatment, but was transformed into Na-cellulose I after 30-day treatment. Na-cellulose I of compression and tension woods was converted to the cellulose I pattern and the mixture of cellulose I and cellulose II, respectively, after washing with water and drying at 20℃. Cellulose I regenerated from Na-cellulose I in wood could not be converted to cellulose II by delignification. Thus, it revealed that the delignification of the alkali-treated wood did not affect their cellulose structures. From the results, therefore, it can be concluded that lignin in woods prevents the formation of the stable Na-cellulose I and the conversion from cellulose I to cellulose II. This means that the conversion of chain polarity of wood cellulose hardly occurs during mercerization because cellulose microfibrils are fixed by lignin which not to be intermingled.

• 분석과학
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• 제10권4호
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• pp.291-299
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• 1997

톱밥의 주성분인 cellulose를 이용하여 cellulose-OH를 cellulose-Cl로 전환시킨 다음 킬레이트 시약인 2,2'-iminodibenzoic acid염을 반응시켜 킬레이트 흡착제인 2,2'-iminodibenzoic acid-cellulose를 합성하였다. 그리고 합성된 흡착제를 이용하여 Pb(II)와 Cu(II)의 흡착성을 연구하였다. 흡착 특성에 대한 실험 결과, pH가 증가할수록 금속 이온의 흡착량이 증가함을 알 수 있었다. 최적 흡착 반응시간은 약 1시간, 흡착능과 회수량은 Cu(II)보다 Pb(II)의 경우가 더 좋음을 알 수 있었다.

• 공업화학
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• 제35권4호
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• pp.352-359
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• 2024

Environmental pollution from heavy metal ions (HMIs) is a global concern. Recently, biosorption methods using cellulose sorbents have gained popularity. The objective of this study was to assess the removal efficiency of Cu(II), Pb(II), and Hg(II) ions at low concentration levels (100-700 ppb) from aqueous solutions using three different cellulose fiber-based filter media. Sample A was pure cellulose fiber, Sample B was 10% activated carbon-cellulose fiber, and Sample C was cellulose fiber-glass fiber-30% activated carbon-20% amorphous titanium silicate (ATS). The samples were characterized by several physicochemical techniques. The porosity measurements using N₂ sorption isotherms revealed that Samples A and B are nonporous or macroporous materials, whereas the addition of 50% filler materials into the cellulose resulted in a microporous material. The Brunauer-Emmett-Teller (BET) surface area and pore volume of Sample C were found to be 320.34 m²/g and 0.162 cm³/g, respectively. The single ion batch adsorption experiments reveal that at 700 ppb initial metal ion concentration, Sample A had removal efficiencies of 7.5, 11.5, and 13.7% for Cu(II), Pb(II), and Hg(II) ions, respectively. Sample B effectively eliminated 99.6% of Cu(II) ions compared to Pb(II) (14.2%) and Hg(II) (31.9%) ions. Cu(II) (99.37%) and Pb(II) (96.3%) ions are more efficiently removed by Sample C than Hg(II) (68.2%) ions. The X-ray photoelectron spectroscopy (XPS) wild survey spectrum revealed the presence of Cu(II), Pb(II), and Hg(II) ions in HMI-adsorbed filter media. The high-resolution C1s spectra of Samples A and B reveal the presence of -C-OH and -COOH groups on their surface, which are essential for HMIs adsorption via complexation reactions. Additionally, the ATS in Sample C facilitates the adsorption of Pb(II) and Hg(II) ions through ion exchange.

• KSBB Journal
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• 제13권2호
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• pp.162-167
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• 1998

The adsorption behaviors of two major cellulase components, endo I and exo II, from Trichoderma viride were investigated using $\alpha$-celluloses with different correlation crystallinity index(Cc) as substrates. The adsorption of cellulase enzyme components was significantly affected by the reaction condition and the physicochemical properties of the cellulose. The $\alpha$-cellulose was hydrolyzed in the presence of cellulase for various periods. The correlation crystallinity index of $\alpha$-cellulose increased with increasing the hydrolysis time. The adsorption was apparently found to obey the first-order kinetics, and the adsorption activation energy(Ea) was calculated from the adsorption rate constant(ka). The value of adsorption rate constant for endo I was larger than that of exo II. This means that endo I are adsorbed more rapidly than exo II. With the increase in correlation crystallinity index, the values of the adsorption rate constants for endo I and exo II decreased, respectively. The activation energy for the adsorption of exo II on the cellulose also was larger than that of endo I. Also adsorption activation energy of endo I and exo II increased with an increase in the crystallinity of sample cellulose.

• Journal of Pharmaceutical Investigation
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• 제36권6호
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• pp.371-375
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• 2006

Neomycin coupled to a polymer matrix via a metal linker was prepared and evaluated for prolonging antibacterial activity. Microcrystallized cellulose was chemically modified to cellulose xanthate(MCX) to afford metal binding sites. MCX was treated with Cu(II), Fe(III) or Zn(II) followed by reaction with neomycin (Ne). The release of Ne from MCX-Zn(II)-Ne was investigated and its activity duration was measured by ditch plate method. The amount of metal bound to MCX was 0.36 mmol/g matrix, 0.26 mmol/g matrix and 0.56 mmol/g matrix for Cu(II), Zn(II) and Fe(III), respectively. Ne bound to MCX-metal chelates was 0.006 mmol, 0.07 mmol and 0.01 mmol per g MCX for Cu(II), Zn(II) and Fe(III), respectively. The Ne release from MCX-Zn(II)-Ne was sustained even after seven washes, whereas Ne from MC/Zn(II)/Ne mixture was almost completely released in two washes. Antibacterial activity was prolonged with MCX-Zn(II)-Ne and MCX-Fe(III)-Ne, but not with MCX-Cu(II)-Ne when compared with that of free Ne. Taken together, these results suggest that neomycin coupled to MCX via a proper metal linker has a potential as a polymeric antibacterial agent with sustained activity.

• Asian-Australasian Journal of Animal Sciences
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• 제6권3호
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• pp.383-388
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• 1993

Three experiments were conducted to investigate the effect of cellulose addition on high (Exp. I) and low (Exp. II and III) dry matter barley straw silages. In Exp. I : 1 kg barley straw + 16 g glucose + 600 g water + 0 g as control (E0G), + 2 g (E2G), + 4 g (E4G), + 6 g (E6G), and + 8 g (E8G) of cellulose as treatments were ensiled. In Exp. II and III, 10 g glucose was and was not added, respectively, into 2 kg barley straw + 0 g (E8W, E8T) of cellulose as treatments. Samples were stored for 10 (Exp. I) and 7 (Exp. II and III) months at $21^{\circ}C$. The effect of cellulose addition on the fermentation and breakdown of the polysaccharides component in the silos at ensiling occurred more markedly at low dry matter silages rather than at the high ones. All cellulose treated silages were well preserved (pH below 5 in Exp. I and below 4 in Exp. II and III), while lactic acid and ethanol concentration increased. The fibrous fraction (ADF, NDF, crude fiber, hemicellulose, and cellulose) significantly (p<0.01) decreased (except hemicellulose content in Exp. I) compared with corresponding untreated silages. In vitro dry matter digestibility values (IVDMD) were similar for all silages. The present study showed that cellulose addition improved the potential nutritional and fermentation quality of barley straw silage.

• 한국염색가공학회지
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• 제5권2호
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• pp.139-143
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• 1993

The effects of air-gap distance on properties of cellulose fiber spun from the 6 wt% solution of cellulose in monohydrate N-methylmorpholine N-oxide (NMMO) were investigated. The diameter of fiber spun was drastically reduced in 10 cm of air-gap distance at fixed drawing speed, however, no great change was observed beyond 40 cm. As the distance lengthened, the Cellulose II structure was first appeared and followed by Cellulose II and IV mixed morphology. Also the degree of crystallinity and the size of crystals were tending to decrease.