• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.43-49
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• 2006

The surface and pore structure of cellulose fibers have a significant impact on the properties and performance in applications. Cellulase enzymatic hydrolysis of cellulose fibers can result in changes to the surface and pore structure thus providing a useful tool for fiber modification. This research characterizes these changes using various test methods such as fiber dimension, water retention value, hard-to-remove water content, freezing and non-freezing bound water content, polymer adsorption, and crystallinity index. For a high-dosage enzyme treatment (0.10 g/g), the fiber length was significantly decreased and the fibers were 'cut' in the cross direction, not in the axial direction. The swelling capacities as measured by the WRV and HR water content increased for the high-dosage treatment. Three independent measurements (non-freezing bound water, polymer adsorption, and crystallinity index) are in good agreement with the statement that the amorphous regions of cellulose fibers are a more readily available substrate relative to crystalline regions. Based on the experimental results obtained herein, a model was proposed to explain surface and pore structure modification of cellulose fibers via enzymatic treatment.

• 펄프종이기술
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• 제43권2호
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• pp.40-48
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• 2011

To build up the conservativeness of aged paper heritages, the strength reinforcement treatment using various cellulose derivative solutions was considered. Hand-made Hanji prepared by traditional papermaking technique was firstly simulated in order to modify the overall of paper properties like aged paper heritages by accelerated ageing treatment at $150^{\circ}C$ for 24 hours, and then the ageing stability of Hanji was verified through the secondary accelerated ageing at $150^{\circ}C$ for 12 hours. The physical properties of aged Hanji were improved by applying with cellulose derivative solutions. The ageing stability for physical, optical (L, brightness, opacity, yellowness) and chemical (oxidation index, degree of polymerization) properties of aged Hanji treated with all kinds of cellulose derivative solutions was also good compared to those of untreated samples, especially using MC solution. Therefore, it was that a kind of MC solution would be well-suited for the strength reinforcement treatment of aged paper heritages.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.69-72
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• 2007

Cellulose is a beneficial material that has low cost, lightweight, high compatibility and biodegradability. Recently electroactive paper (EAPap) on cellulose base was discovered as a smart material and actuator through ion migration and piezoelectric effect. Furthermore cellulose has a potentiality to apply the display material, because of its high reflectivity, flexibility and high transmittance. The various shapes and height patterns of the Cellulose acetate (CA) solution, such as circle and honeycomb patterns, were fabricated and observed by field emission scanning electron microscope (FESEM, S4300 Hitachi). The resulting pattern showed uniform size in the large area without defect. After stretching the CA film with saponification process in the sodium methoxide in methanol solution, Most of the compositions become one directional ordered nanofibers below 50nm.

• 펄프종이기술
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• 제39권5호
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• pp.20-25
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• 2007

Henequen fibers were treated by electron beam irradiation and by NaOH to make surface modification for better bonding in the manufacture of biocomposite. Impurity removal and carbonyl group formation were noticed in the previous study by electron beam irradiation, but extensive cellulose degradation were also noticed. To evaluate the effects of electron beam irradiation on cellulosic fibers further, henequen fibers, cotton pulp, cotton fibers, and cellophane were irradiated by electron beam, and their changes of cellulose viscosity, chemical composition, and tensile strength were measured and analyzed.

• Macromolecular Research
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• 제17권2호
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• pp.116-120
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• 2009

The cellulose smart material called electro-active paper (EAPap) is made by regenerating cellulose. However, the actuator performance is degraded at low humidity levels. To solve this drawback, EAPap bending actuators were made by activating wet cellulose films in three different room-temperature ionic liquids: l-butyl-3-methylimidazolium hexaflurophosphate ($BMIPF_6$), 1-butyl-3-methylimidazolium chloride (BMICL) and 1-butyl-3-methylimidazolium tetrafluroborate ($BMIBF_4$). In the results, the actuator performance was dependent on the type of anions in the ionic liquids, in the order of $BF_4$>Cl>$PF_6$. The BMIBF 4-activated actuator showed the maximum displacement of 3.8 mm with low electrical power consumption at relatively low humidity. However, the BMICL-activated actuator showed a slight degradation of actuator performance. Further performance and durability improvement will be possible once various ionic liquids are blended with cellulose.

• 펄프종이기술
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• 제39권3호
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• pp.77-83
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• 2007

This study was carried out to examine the optimum culture condition for the production of cellulose from Saprolegnia ferax and its physical characteristics. Conclusions obtained from the results of this study were as follows: In producing the cellulose from S. ferex, optimal pH and temperature were 7.0 and $26{\sim}30^{\circ}C$ with a maximum of $26^{\circ}C$, respectively. And, optimal culture period was 11days. WHC and OHC of biocellulose were 3.2(25.04 g/g) times and 3.5(25.75 g/g) times higher than those of commercial ${\alpha}-cellulose$(7.57, 7.25 g/g) respectively. The viscosity of biocellulose is lower than that of commercial ${\alpha}-cellulose$. And the effect of rpm on the viscosity of biocellulose was more than on the that of ${\alpha}-cellulose$.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.480-483
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• 2008

This paper reports a piezoelectric paper made with cellulose. Since cellulose has merits in terms of biodegradability, biocompatibility, abundance in nature, lightweight and cheap, piezoelectric paper can bring a broad technological impact in many areas, for example, sensors, actuators, speakers, microphones and microelectromechanical systems. Fabrication and characterization of the piezoelectric paper are illustrated and its possibility for acoustic applications is addressed with some preliminary device demonstrations.

• 펄프종이기술
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• 제31권2호
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• pp.1-7
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• 1999

In this paper, five lignin model compounds (vanilly alcohol, veratryl alcohol, veratryl methyl carbinol, biseugenol) and three cellulose model compounds (${\alpha}$-D-glucos, methyl-${\beta}$-D-glucopyra-noside, D-cellobiose) were used to study the degradation rates of lignin and cellulose with chlorine dioxide. Biseugenol, which has unsaturated structure on the side chain of aromatic ring, was found to react with chlorine dioxide very quickly and consume large amount of chlorine dioxide. Phenolic structures, represented by veratryl alcohol and apocynol, react with chlorine dioxide much faster than nonphenolic structures represented by veratryl alcohol and veratryl methyl carbinol. The degradations of cellulose models were generally very slight, the corder of reaction rate being ${\alpha}$-D-glucose > D-cellobiose > methyl-${\alpha}$-D-glucopyranoside.

• 펄프종이기술
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• 제47권2호
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• pp.17-23
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• 2015

Natural cellulose hydrogel membrane cannot be directly used for cell encapsulation because it has many large pores on the surface that immune biomolecules are able to penetrate into easily. For the reason, alginate was used for the control of pore size of the cellulose hydrogel membrane. The surface morphology of cellulose/alginate nanocomposite confirmed the successful control of the porosity of the membrane. The permeability of the cellulose/alginate nanocomposite was decreased but mechanical properties were increased compared with the bacterial cellulose membrane. The cellulose/alginate nanocomposite could be used for the functional membrane as a promising biomedical material in the future.

• 한국정밀공학회지
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• 제30권2호
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• pp.241-246
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• 2013

This paper reports fabrication and characterization of cellulose Electro-Active Paper (EAPap) with increased thickness. Usual thickness of cellulose EAPap was $15{\mu}m$. This thickness needs to be increased to enhance the mechanical force output of EAPap. To fabricate thick cellulose EAPap, the fabrication process parameters including casting and drying processes should be investigated. In this paper, the casting thickness is increased from $800{\mu}m$ to $1500{\mu}m$, and heating times on a hot plate before and after curing process are introduced at 40 and $60^{\circ}C$ for 30 and 60 minutes, respectively. Thickness measurement, Thermal Gravitational Analysis (TGA), UV-transmittance, Young's modulus, and piezoelectric charge constant are measured. Heated EAPaps with increased thickness have similar TGA result, higher transmittance, higher Young's modulus and lower piezoelectric charge constant.