• Fibers and Polymers
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• 제6권2호
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• pp.139-145
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• 2005

The paper reports the physical and mechanical properties of hand-woven carpets, which have been put under static force. Two groups of wool fibres, from two parts of Iran, were prepared to spin pile yams for the carpets. Each group of the fibres included both conventional and tanned wool. Then two yam counts, $N_m$ = 4/2 and 6/2, were spun for two different knot densities. After weaving the carpets, they were put under static force and their thickness variations were measured and plotted against time, in logarithm scale. The resiliency of the carpets piles after eliminating the static force, were measured and plotted against time, in logarithm scale, too. The results were compared to each other and analysed with respect to parameters such as the type and quality of the wool fibres as well as knot density of the carpets.

• Archives of Metallurgy and Materials
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• 제63권3호
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• pp.1497-1502
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• 2018

Macroporous silica fibers having spherical cavities were fabricated by electrospinning using the spinning solution prepared from the mixed dispersion of tetraethylorthosilicate (TEOS) and polystyrene nanospheres as precursor and sacrificial templates, respectively, by injection through metallic nozzle. By applying electric field, the electro-spun fibers obtained by evaporation-driven self-assembly were collected on flat substrate or rotating drum, followed by the removal of the templates by calcination. The sound absorption coefficient of the porous fibers was measured by impedance tube, and the measured value was larger than 0.9 at high frequency region of incident waves. The surface of the resulting fibers was modified using fluorine-containing silane coupling agent to produce superhydrophobic fibrous materials to prevent the infiltration of humidity.

• 한국염색가공학회지
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• 제3권2호
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• pp.16-24
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• 1991

The textile fabric have the functions of sanitation, decoration, wearing style and washing in the practical use. Among various texitle fiber, silk has less utilities than synthetic fiber in practical use although silk has good benefits of the high quality. Thus no textile fiber, neither natural nor synthetic, has all the functions. In this sence, many blend yarns have been improved various functions of fabric. However, this has been disturbed with the problem of dyeing, especially in the case of blend fabric of silk. In this study, we dyed silk/PET blend fabric in one step useing one bath dyeing method by acid dyes/disperse dyes. The results of the experiments can be summarized as follows; 1) Yellow index of silk fabric treated at $130^{\circ}C$ increased about 7.8 (color difference 4.5 NBS) and whiteness decrease about 5%. 2) Both elongation and tensile strength of silk fabric treated at $130^{\circ}C$ of pH 5-6 decreased about 10% and tensile strength of silk spun yarn treated at $60^{\circ}C$ of pH 10 have little changed. 3) While silk/PET blend frbric dyeing, silk soiling of disperse dyes causes from difference of dyeing rate and degree of silk soiling with dyes. 4) Fastness and soiling of silk/PET blend fabric dyed by one bath dyeing method of acid dyes/disperse dyes was same as two bath dyeing method.

• 폴리머
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• 제24권6호
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• pp.810-819
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• 2000

Poly(p-hydroxybenzoate) (PHB)/poly(ethylene terephthalate) (PET) 8/2 공중합 폴리에스터 액정고분자와 poly(ethylene 2,6-naphthalate) (PEN), PET를 용융방사하여 인장탄성률을 측정하고, 55$^{\circ}C$ ο-chlorophenol 에서 2시간 동안 모재인 PEN/PET부분을 용출시킨 후, 용출되지 않은 PHB 피브릴을 전자현미경으로 조사하였다. 모재고분자 속에 존재하는 피브릴이 단섬유일 때 적용하는 Halpin-Tsai식과 피브릴이 연속상일 경우 적용하는 혼합의 법칙을 사용하여 이론적인 탄성률을 계산하고, 측정된 탄성률과 비교하였다. 이론적 탄성률과 측정된 탄성률의 차이를 보정하기 위하여 무차원 점도비 상수 (K)를 정의하고, K를 적용하여 기존의 식을 변형하였다. 변형된 Halpin-Tsai식과 혼합의 법칙을 통해 계산된 이론적인 탄성률은 용융방사를 통해 제조된 복합재료의 탄성률 계산에 더 적합함을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2253-2258
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• 2009

wet spun polyacrylonitrile (PAN) fiber precursors. The process variables chosen were treatment temperature, applied tension in stabilization process. The temperature profile of the stabilization was set on the basis of exothermic peaks of the differential scanning calorimetry (DSC) result. Both tensile strength and modulus increased with holding at onset temperatures of the exothermic peaks for extended duration, and with a higher heating rate up to the onset temperatures at a given applied tension among the experimental conditions. The increase in load monotonously increased the tensile modulus, on the other hand, the tensile strength was maximum at the load of 15 mg/filament (T15). The load 20 mg/ filament (T20) was considered to be exceeded to form oriented crystalline structure, possibly introducing more defects in the fiber than under load of T15. The sample CP3-T15 O5 H30 showed the best tensile properties among the samples experimented whose tensile properties are compatible with the commercialized grade of general purpose carbon fibers even at low carbonization temperature such as $800\;{^{\circ}C}$ (the carbonization temperature in the commercial process. 1300∼$1500\;{^{\circ}C}$).

• 멤브레인
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• 제23권5호
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• pp.332-342
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• 2013

본 연구에서는 Matrimid-5218로부터 메틸이미드 중공사 전구체를 비용매 유도 상분리법으로 제조한 후에 탄화시켜 탄소 분자체 중공사 분리막을 제조하였으며 전처리, 열분해, 후처리 공정이 탄소 분자체 중공사 분리막의 기체 투과 특성에 미치는 영향을 살펴보았다. $250^{\circ}C$에서 2시간 공기 중에서 전처리하고, $550^{\circ}C$에서 2시간 질소 분위기에서 열분해한 후, $250^{\circ}C$에서 2시간 공기 중에서 후처리할 때에 가장 높은 기체 투과특성을 갖는 분리막이 제조되었다. 제조된 탄소 분리막은 $H_2$, He, $CO_2$ 투과도가 69.72, 35.61, 31.01 GPU이었으며 $O_2$, $N_2$ 가스는 거의 투과하지 않았다. 따라서 제조된 탄소분자체 중 공사 분리막은 $H_2$, He 등 작은 분자 기체와 $CO_2$ 회수용 분리막으로서 우수한 소재임을 확인할 수 있었다.

• 멤브레인
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• 제32권2호
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• pp.140-149
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• 2022

본 연구에서는 폴리술폰 분리막을 이용한 바이오가스 정제 공정으로 고선택성 소재를 이용한 2단 공정의 높은 회수율 및 경제성과 동등한 수준의 회수율을 확보하기 위해 저온 고압의 분리막 공정을 설계하고 평가하였다. 폴리술폰 고분자를 4성분계 도프를 이용하여 비용매 유도 상전이법으로 중공사 분리막을 제조하였다. 기체 분리용 중공사 분리막은 1.6 m²의 유효 막면적을 갖는 샘플을 제조하여 상온 및 저온에서 기체 투과 특성을 평가하였다. 제조된 기체분리막 모듈의 온도에 따른 기체 투과 특성을 분석하기 위하여 온도별 단일 기체 투과도를 평가한 결과 이산화탄소와 메탄 투과도는 20℃에서 각각 412, 12.7 GPU이며, -20℃에서는 각각 280, 3.6 GPU로써 이상 선택도는 32.4에서 77.8로 향상되었다. 단일 기체 투과 테스트 후 혼합 기체에 대한 분리 테스트를 진행하였으며, 모듈 1단 구성 및 2단 구성(막 면적비 1:1, 1:2, 1:3)을 통하여 투과 거동을 살펴보았다. 1단 구성에서는 stage-cut이 상승함에 따라 메탄의 농도가 상승하지만, 반대로 회수율은 떨어지는 결과를 나타내었다. 2단 구성 테스트에서는 메탄 농도 97% 기준에서 막 면적비 1:1보다 1:3이 메탄의 회수율이 더 높게 측정되었으며, 공급 기체의 온도가 낮을수록 메탄의 회수율이 높아짐을 확인하였고, 최종적으로 폴리술폰 2단 공정에서 메탄 농도 97%, 회수율 97%의 결과를 달성하였다.

• Fibers and Polymers
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• 제6권3호
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• pp.206-218
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• 2005

Structural studies of series of 'as spun' and drawn PEEK fibers have been carried out using X-ray diffraction and optical microscopy techniques. The analysis of results suggest that fibers produced at a constant draw ratio with increasing draw temperatures show enhanced orientation and crystalline behaviour. The resolved equatorial and meridional traces provide additional structural parameters in terms of crystallinity, crystallite size, and crystallite thickness. It is concluded that drawing at a temperature below $T_g(i.e.,\;144^{\circ}C)$ results in poorly oriented non-crystalline materials, whereas drawing above $T_g$ results in highly oriented semi crystalline materials. Additional drawing proved to increase the overall orientation with slight improvements in lateral order of the chain molecules. Quantitative analysis revealed that the crystallite size increases with increasing drawing temperature. The results also revealed the increased crystallite size upon additional drawing. Crystalline orientation parameter, $_c$, suggests almost perfect orientation. In all cases, the amorphous orientation is found to be lower than the overall orientation parameter obtained from the optical birefringence. As a result of additional drawing, crystalline orientation was found to increase slightly but the increase in the orientation of non-crystalline material was found to be substantial. An average crystalline density was determined from the orthorhombic unit cell dimensions. It was found to vary as a result of processing conditions. It was also found that the value of the maximum birefringence shows heavy dependence on the chain conformation.

• 한국의류학회지
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• 제37권2호
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• pp.224-234
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• 2013

This study investigates the fabrication of core-sheath nanocomposite fibers by locating germanium (Ge) and silicon dioxide ($SiO_2$) nanoparticles selectively in the sheath layer by co-axial electrospinning. Co-axially spun fibers were prepared by electrospinning a pure PVA solution and Ge/$SiO_2$/PVA solution as the core and sheath layer, respectively. Core-sheath nanocomposite fibers were electrospun under a variety of conditions that include various feed rates for the core and sheath solutions, voltages, and concentric needle diameters, in order to find an optimum spinning condition. Ge/$SiO_2$ nanocomposite fibers were also prepared by uniaxial electrospinning to compare fiber morphology and nanoparticle distribution with core-sheath nanofibers. Using scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis, it was demonstrated that the co-axial approach resulted in the presence of nanoparticles near the surface region of the fibers compared to the overall distribution obtained for uni-axial fibers. The co-axially electrospun Ge/$SiO_2$/PVA nanofiber webs have possible uses in high efficiency functional textiles in which the nanoparticles located in the sheath region provide enhanced functionality.

• 한국식품과학회지
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• 제10권2호
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• pp.143-150
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• 1978

저자들은 전보(Korean J. Food Sci. Techno., 9,123(1997)에서 분리 대두 단백의 식품학적 성질을 조사하였다. 본 연구에서는 이 성질을 응용하여 대두 단백섬유를 제조하고저 분실 험실에서 고안 설계하여 의뢰제작한 protein spinning apparatus를 사용하여 분리 대두단백으로 대두단백섬유 제조실험을 행한결과 texture가 우수한 제품을 얻었다. 제조조건은 15-18% 단백질용액을 알카리 (0.6%)로 처리하여 50-100 PSI spinning press로 사출한 후 12% Nacl-1 N acetic acid bath에서 응고시켰다. 12% 단백질 용액은 생성된 단백섬유의 texture가 불량하여 일정한 모형을 유지하지 못하였다. 제품의 성질을 Instron기기와 texturometer를 사용하여 측정하였다. 아울러 대두 단백섬유의 형성기작을 제시하였다.