• KSBB Journal
• /
• 제11권2호
• /
• pp.218-224
• /
• 1996

The adsorption of cellulase on celluloses with different crystallinities was carried out In nonionic surfactant(Tween 20) solution. Highly crystallized celluloses were prepared by enzymatic prehydrolyzation. From the experiments, the Langmuir isotherm parameters, maximum adsorption amount (Amax) and adsorption equilibrium constant(Kad) for the adsorption, were obtained in the presence and absence of nonionic surfactant. It was found that the Kad values were decreased by adding Tween 20. This indicates that the adsorption affinity is reduced by nonionic surfactant, and Amax decreased with increasing crystallinity under conditions accompanying in both the presence and absence of surfactant. The thermodynamic parameters such as $\Delta$Ha, $\Delta$Ga, and $\Delta$Sa for the adsorption were calculated by using the experimental data. From these results, it was found that the adsorption processes are exothermic reactions in both the presence and absence of surfactant. The heats of adsorption in surfactant solution(-4.68∼-3.62KJmol-1) are smaller than that of the adsorption in the absence of surfactant(-15.60∼-12.10KJmol-1). These results indicated that the tightness of adsorption was reduced by the addition of surfactant. The $\Delta$Sa values were estimated to be positive. This may suggest that the water and solute are released from cellulose on adsorption. The $\Delta$Sa values in surfactant solution are larger than that of the adsorption in the absence of surfactant. This may suggest that the binding of surfactant on hydrophobic region of cellulase cause dispersion of water and solute molecule orienting around the enzyme molecule. The surfactant played an important role in the desorption of enzyme from cellulose functional groups, and enhance the saccharification of the cellulose.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
• /
• pp.149-152
• /
• 1999

A new process for deinking of colored offset newsprint, i.e. enzyme treatment in cooperation with ultrasonic wave was developed in the present study. The physical characteristics such as fiber length, coarseness, crystallinity index of the deinked pulps were investigated and the sugar residues released from the treatment were analyzed. It was found that colored offset newsprint could be deinked effectively by cellulase treatment when ultrasonic wave was applied. The brightness increased by 5% ISO over that of control experiment and the pigment content was reduced markedly. Though the ultrasonic wave had little effect on the strength and crystallinity of the pulp, the treatment of enzyme combined with ultrasonic wave reduced the coarseness and fiber length to some extent. It was also found that ultrasonic wave could accelerate the hydrolysis of cellulose and hemicellulose during the cellulase treatment.

• Journal of the Korean Wood Science and Technology
• /
• 제35권6호
• /
• pp.91-99
• /
• 2007

소나무, 낙엽송, 리기다소나무, 잣나무 등 국내산 침엽수 목분을 기질로 진탕배양했을 때 갈색부후균인 Fomitopsis palustris로부터 분비된 당 분해성 균체 외 효소는 Endoglucanase (EG), $\beta$-glucosidase (BGL) 및 $\beta$-1,4-xylosidase (BXL)와 함께 결정형 셀룰로오스를 분해하는 Cellobiohydrolase (CBH)도 활성을 갖은 것으로 나타났다. 4주간 배양에서 변재는 심재에 비해 큰 효소활성을 나타냈으나, 배양기간을 증가시킴으로써 효소활성이 커지는 것으로 밝혀져 효소에 의한 목질바이오매스 분해의 경우 심변재 혼합처리도 가능할 수 있음이 시사되었다. 그리고, 균체 의 단백질을 SDS-PAGE로 분석한 결과, 대부분의 수종에서 나타나는 효소의 단백질 패턴은 거의 유사한 것으로 나타나 효소를 이용한 목질계 바이오매스 분해의 경구 수종별 혼합처리도 가능함이 시사되었다. F. palustris에 의해 분해된 목분(60 mesh 통과) 셀룰로오스의 결정화도 감소율은 4주 배양에서 약 4.2~20.4%, 8주 배양에서 약 12.9~28.9% 수준으로 나타났다.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
• /
• pp.83-84
• /
• 2003

The microstructure and tensile properties of ramie treated with NaOH and crosslinked with 1, 2, 3, 4-butanetetracarboxylic acid were characterised. X-ray diffraction and FTIR were used to study the crystalline structure o f the resultant ramie yarns. Results showed that the maximum change in the structure of the modified ramie took place at 16% NaOH, which would completely transform Cellulose I to Cellulose II. Also, the crystallinity index and fibre orientation decreased to the minimum value while the absorption properties were enhanced. The average degree of polymerization of the treated ramie yams slightly decreased after NaOH treatment.

• 한국염색가공학회지
• /
• 제2권3호
• /
• pp.51-58
• /
• 1990

Cotton fabrics were mercerized in ammonia water, sodium hydroxide and mixture of ammonia/sodium hydroxide, slack and under tension. X-ray and infrared spectra analyses were used to measure crystallinity of treated cottons. Changes due to swelling, which took place in the accessible regions were determined by moisture regain and dye adsorption. In addition to that crease recovery was compared mutually, and breaking strength-elongation compared, too. Both ammonia water and caustic treatments produced changes in morphology (swollen fibers, decrease in convolutions) and in fine structure of the cellulose (increase accessibility as measured by increased moisture regain, dye adsorption). X-ray diffraction showed partial recrystallization into cellulose III lattic after tension treatment with ammonia water. Both reagents produced increased cotton elongation-at-break with slack mercerization, increased cotton breaking strength with tension mercerization, and increased moisture regain or dye adsorption with slack mercerization.

• 펄프종이기술
• /
• 제48권3호
• /
• pp.37-43
• /
• 2016

Various mechanical and chemical pretreatment methods including alkali treatment, pre-beating, enzyme treatment and oxidation treatment have been used to reduce the production energy of the microfibrillated cellulose (MFC). Among them, alkali swelling can be helpful to reduce the energy consumption because the internal bonding between fibrils could be weakened. In this study, dimethyl sulfoxide (DMSO) was used as a cosolvent to improve alkali pretreatment efficiency and the effects of NaOH concentration during NaOH-DMSO swelling on changes in fiber characteristics of softwood bleached kraft pulp (SwBKP) were elucidated. For alkali treatment in H2O-DMSO solvents, fiber length were decreased with increasing NaOH concentration while fiber width, curl and WRV were increased. WRV began to increase at 8% NaOH solution. In addition, above 8% concentration of NaOH, crystalline structure of pulp fibers converted from cellulose II to cellulose III by DMSO cosolvent. Comparing the previous results with this study, it was shown that DMSO cosolvent could promote swelling of pulp fibers and thus reduce NaOH concentration for the maximum swelling of fibers.

• 공업화학
• /
• 제16권2호
• /
• pp.257-261
• /
• 2005

미생물에 의해 생산된 셀룰로오스는 고등식물을 이루고 있는 셀룰로오스보다 순수한 형태로 존재하고 굵기가 20~50 nm인 fibril이 높은 배향성과 결정성으로 3차원적 망상구조를 이루고 있다. 이러한 미생물 셀룰로오스를 이용한 탄화과정의 적용은 기존의 PAN, Pitch, 재생 셀룰로오스(Rayon)를 사용한 탄소 섬유의 제조에서 얻지 못하는 섬유 구조 탄소 물질의 대량 생산을 가능하게 하고 탄화과정에 의해 생산된 섬유 구조의 탄화 셀룰로오스는 높은 결정성과 배향성을 갖는 나노 영역의 흑연 결정상의 섬유 제조를 가능하게 할 것이다. 탄화에 사용되는 셀룰로오스의 생산성에 대하여 세 가지 균주들에서 생산된 셀룰로오스의 양을 비교하여 G. xylinus ATCC 11142가 15mL 배지당 건조 질량 0.066 g의 셀룰로오스를 생산하는 것을 확인하였고 셀룰로오스의 탄화과정에서 셀룰로오스의 열분해에 의해 생산된 타르(tar)에 의해 탄화 후, 셀룰로오스 탄화물의 섬유 구조를 저해시키는 문제점이 존재한다. 이러한 문제를 해결하기 위하여 탄소 나노튜브의 정제과정에서 연구된 액상, 기상 그리고 초음파 처리를 통한 정제방법들을 적용하여, 탄화 셀룰로오스에서는 초음파 처리를 통한 정제과정의 적용이 셀룰로오스 탄화물에서 섬유 구조가 증가하는 결과를 나타냈다.

• Journal of the Korean Wood Science and Technology
• /
• 제40권3호
• /
• pp.156-163
• /
• 2012

본 연구에서는 국내산 리그노셀룰로오스 자원을 이용하여 기계적 처리를 통해 나노섬유를 제조 후, 형태학적 특성 및 고강도 시트로의 응용 가능성을 평가하였다. 그 결과, 연속식 분쇄 처리는 세포벽의 구조를 느슨하게하고 분쇄 소요 시간이 증가함에 따라 나노스케일에 가까운 섬유가 관찰되었다. 재료의 미립화 정도를 증명하는 여수시간은 모든 공시재료에서 분쇄 소요시간이 증가함에 따라 직선적인 증가 경향을 나타내었다. 셀룰로오스의 상대결정화는 기계적인 해섬처리 정도에 따른 차이를 보이지 않았으나 탈리그닌 처리에 의해 크게 증가하였다. 셀룰로오스 나노섬유 시트는 기계적인 분쇄 소요시간이 증가함에 따라 인장강도가 증가하였고 옥수수줄기를 이용한 시트에서 특히 높은 인장강도가 측정되었다. 상기와 같은 결과는 국내 자생 식물자원을 활용한 셀룰로오스 나노섬유 제조 기술의 유용한 기초자료로 활용될 수 있을 것으로 판단된다.

• 한국의류학회지
• /
• 제35권8호
• /
• pp.982-990
• /
• 2011

Kenaf fiber can be obtained by decortications of the kenaf plant stem. The properties of the kenaf fiber treated by alkali (NaOH) were investigated by spectrocolorimeter, SEM, X-ray diffractometer, FT-IR and TGA. The kenaf fibers treated by alkali became darker and their Munsell color values changed from Y (yellow) to YR (yellowred) according to an increased NaOH concentration. SEM observation of the kenaf fibers showed that their crimps were developed and their surfaces were cleaned by the removal of protruding ends and impurities after alkali treatments. In the x-ray diffraction analysis, the structures of the fibers were found in the form of cellulose I when treated with a 0-16% alkali concentration and cellulose II when treated with over 20%. It was also confirmed that the crystallinity was lowered according to an increased NaOH concentration. The change of fiber compositions was investigated in FT-IR analysis. Strong band of $1,738cm^{-1}$ and asymmetrical stretching strong bands of $1,630-1,600cm^{-1}$ in spectrum (which represent pectin) were not found in the samples because the pectin was removed by the alkali treatment. Weak bands of $1,728-1,730cm^{-1}$ and peaks of $1,245-1,259cm^{-1}$ (which represent hemicellulose) and peaks of $1,592cm^{-1}$, $1,504cm^{-1}$, $1,462cm^{-1}$ and $1,429cm^{-1}$ (which are related to lignin) were not found or reduced in the samples treated with a concentration over 20%. TGA indicated that the kenaf fiber had the better hydrophilic properties by alkali treatment. The higher Tmax in TGA and the higher thermal stability when treated by alkali with the higher concentration. The fibers treated with an alkali concentration over 30% did not show any changes in Tmax.

• 폴리머
• /
• 제34권3호
• /
• pp.210-214
• /
• 2010

트리아세틸 셀룰로오스(triacetyl cellulose, TAC) 용액필름 가공 시, 가공 공정 변수인 TAC 도프(dope)의 농도, 용매 제거 온도, 열처리 온도와 흐름특성 증가를 위하여 사용되는 가소제의 첨가가 TAC 필름의 구조 변형에 미치는 영향을 살펴보았다. 사용 도프의 농도가 높을수록, 용매 제거 온도가 높을수록 TAC의 결정화가 더 잘 발현됨을 알 수 있으며 이러한 결정화는 TAC 필름의 제조 후 열처리에 의하여 증가됨을 확인하였다. 또한, 가소제의 첨가에 의한 주사슬의 유연성 증가에 의하여 용융온도 및 결정화도가 감소하며 첨가된 가소제의 방향족 구조로 인하여 필름의 열분해 안정성이 우수해짐을 알 수 있었다.