실크 세리신의 구조와 성질에 대한 최근 연구동향

엄인철,Um, In Chul 한국잠사학회 2019 한국잠사곤충학회지 Vol.55 No.2

Sericin has been removed in textile industry to improve the luster and hand of silk textile. Therefore, the sericin was considered as useless material. However, recently sericin has attracted researcher's attention since unique properties of sericin including high water retention, UV protection, and wound healing effect were reported. In spite of the useful properties of sericin as biomedical and cosmetic materials, its poor mechanical properties have restricted its industrial use in biomedical and cosmetic fields. To improve the mechanical properties, various sericins were prepared by different conditions, and the effects of the preparation condition on the structure and properties of sericin were examined. In this review paper, research trend in the structure and properties of sericin prepared with different conditions were intensively introduced.

셀룰로오스 에테르를 첨가한 쌀면의 기계적 물성

엄인철,유영진,Um, In Chul,Yoo, Young Jin 경북대학교 농업과학기술연구소 2013 慶北大農學誌 Vol.31 No.3

본 연구에서는 셀룰로오스 에테르의 분자량, 치환도 및 치환체가 이들을 첨가한 쌀건면의 기계적 물성에 주는 영향에 대해 살펴보았다. HPMC의 분자량이 증가함에 따라, 쌀건면의 굽힘강도는 서서히 증가하였으나, 밀면의 강도보다는 낮은 수준을 나타냈다. 분자량이 증가함에 따라, 쌀건면의 굽힘신도는 서서히 감소하였으나, 밀면의 신도보다는 모두 높은 값을 나타내어 셀룰로오스 에테르 첨가가 쌀건면의 신도 향상에 기여했음을 확인하였다. 셀룰로오스의 치환도 및 치환체에 따라서는 굽힘강도 및 굽힘신도가 다소 차이가 있는 것으로 나타났다. This study examined the effect of the molecular weight, substitution degree, and substitution type of cellulose ether on the mechanical properties of dried rice noodles. When increasing the molecular weight of the hydroxypropyl methylcellulose (HPMC), the bending strength of the dried rice noodles also increased. However, the bending strength of the rice noodles with added HPMCs was still lower than that of the wheat noodles. Meanwhile, the bending elongation of the dried rice noodles was higher than that of the wheat noodles and was increased when decreasing the molecular weight of the HPMC. In conclusion, the bending strength and elongation of dried rice noodles is affected by the substitution degree and type of cellulose ether.

알칼리 처리에 따른 아마섬유의 헤미셀룰로스 제거와 결정구조 전이

엄인철,권해용,박영환,Um, In Chul,Kweon, Hae Yong,Park, Young Hwan 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.5

In this study, delignified flax fiber was treated with a NaOH aqueous solution. XRD diffractometry and FTIR spectroscopy were utilized to examine the structural transition of the alkali-treated flax fibers. Also, the effect of the hemicellulose removal on the structural change of flax fibers was discussed. XRD measurement revealed that the crystallinity of cellulose I increased at low NaOH concentration (3%) due to the elimination of amorphous hemicellulose. The structural transition from cellulose I to cellulose II occurred in a NaOH concentration range of 12~15%. Considering most hemicellulose in flax fiber is removed at 12% NaOH, it can be assumed that the presence of hemicellulose in flax fiber has a role in preventing the structural change of flax cellulose. IR absorbance ratios ($A_{1370cm}{^{-1}}/A_{2900cm}{^{-1}}$ and $A_{1430cm}{^{-1}}/A_{2900cm}{^{-1}}$) were utilized as a barometer of cellulose I crystalline exhibiting a similar result with the cellulose I crystallinity from XRD. Another absorbance ratio ($A_{895cm}{^{-1}}/A_{2900cm}{^{-1}}$) reflected the cellulose II crystalline showing almost the same trend as cellulose II crystallinity. On the whole, the total crystallinity of flax fiber was increased at low NaOH concentration (3%) and decreased at 12% due to the reduction of cellulose I content and increased again at 15% attributed to the formation of cellulose II content.

히드록시프로필 메틸셀룰로스의 습식방사

엄인철,조혜빈,강경돈,Um, In-Chul,Cho, Hye-Bin,Kang, Gyung-Don 한국섬유공학회 2009 한국섬유공학회지 Vol.46 No.5

In this study, hydroxypropyl methylcellulose (HPMC) filaments were prepared by the wet spinning process, and the coagulation behaviors of HPMC dope and the morphology of wet spun HPMC filaments were investigated. THF, acetone, and iso-propanol showed a partial coagulation strength for HPMC dope though they did not produce a filament form. On the other hand, a high temperature water could coagulate the HPMC dope due to the gelation character of HPMC solution. However, the temporarily coagulated HPMC filament returned to a solution state when it came out of the coagulation bath. This problem, due to the reversible gelation behavior of HPMC, could be solved by adding salts in the water (coagulant). As the salt concentration increased in the coagulant, the coagulation strength was improved resulting in a reduced fiber forming temperature. Furthermore, ammonium sulfate was turned out to be the most effective salt to enhance the coagulation of HPMC in aqueous salt solution. The thermo-rheological measurements revealed that ammonium sulfate was the most effective in reducing the flocculation and the gelation temperatures among salts tested. The HPMC filament could be produced finally with the help of second coagulation bath containing organic solvent. Among the organic solvents, isopropanol was the best coagulant yielding the highest post drawing ratio of HPMC filament. The SEM observation indicated that the wet spun HPMC filament had irregular surface and cross section. The surface of HPMC could be smoother when the salt concentration was reduced to 8%.

셀룰로오스 에테르 첨가 쌀 면의 조리 특성

엄인철,유영진,Um, In Chul,Yoo, Young Jin 경북대학교 농업과학기술연구소 2014 慶北大農學誌 Vol. No.

This study uses turbidity and rheological measurements to examine the effects of the molecular weight (MW), substitution type and substitution degree of cellulose ether and water content on the cooking characteristics of rice noodles, the turbidity of the cooking solution, and the compression strength of the cooked noodles. When increasing the MW of cellulose ether and water content, the turbidity decreased, thereby improving the morphological stability of the rice noodles during cooking. Thus, when controlling the above factors effectively, the rice noodle cooking solution had a lower turbidity than with wheat noodles. Measuring the compression strength of the rice noodles using a rheometer was also effective for examining the pasting characteristics of the rice noodles and texture changes during cooking. As a result, the water content and MW of cellulose ether were found to affect the pasting characteristics and texture of the rice noodles more than the other factors examined. 셀룰로오스 에테르의 분자량, 첨가량, 치환도 및 치환체 종류, 물 양이 쌀면의 조리특성에 주는 영향을 살펴보기 위해 자외선 가시광선 분광분석기를 이용하여 조리 후 쌀면 국물 탁도 를 측정하고 유변물성 측정기를 이용하여 쌀면의 압축강도를 측정하였다. HPMC의 분자량 및 물 양이 증가할수록 국물의 탁도가 감소하여 조리 시 쌀면의 형태안정성이 향상되었고, 셀룰로오스 에테르 첨가량, 치환체 종류, 치환도에 따라 탁도 값이 변화하여, 이들 인자 모두가 쌀면의 형태안정성에 영향을 준다는 것을 확인하였다. 또한, 이들 인자를 효과적으로 조절할 경우, 밀면을 조리한 국물의 탁도보다 낮은 탁도값이 얻어져 셀룰로오스 에테르의 첨가에 따라 조리 시 쌀면의 형태안정성이 크게 향상됨을 확인하였다. 유변물성 측정기를 이용한 쌀면의 압축특성 측정은 조리시간에 따른 쌀면의 호화정도 및 변화하는 조직감을 살펴보는 데 효과적이였으며, 물 양 및 셀룰로오스 에테르의 분자량이 다른 인자들에 비하여 조리시간 별 쌀면의 호화특성 및 조직감에 큰 영향을 주는 것으로 나타났다.

유변물성 측정기를 이용한 셀룰로오스 에테르가 첨가된 쌀 반죽의 압축 및 접착 특성

엄인철,유영진,Um, In Chul,Yoo, Young Jin 경북대학교 농업과학기술연구소 2014 慶北大農學誌 Vol.32 No.1

The present study examined the effect of cellulose ether on the compression and adhesion characteristics of rice dough using a rheometer. When increasing the amount of hydroxypropyl methylcellulose (HPMC), the adhesion strength consistently increased. However, the compression strength of the rice dough was the highest with 2% HPMC. When increasing the molecular weight and decreasing the water content, the compression and adhesion strength of the rice dough were both increased. Furthermore, the substitution type and degree of cellulose ether were also found to be key factors determining the compression and adhesion strength of the rice dough. 본 연구에서는 유변물성측정기를 이용하여 HPMC 첨가량, 물 양, HPMC 분자량, 셀룰로오스 에테르 치환제 및 치환도가 쌀 반죽의 압축 및 집착 특성에 미치는 영향에 대해 살펴보았다. HPMC 첨가량이 증가함에 띠라 접착강도는 꾸준히 증가하였으나, 압축강도는 2% HPMC 첨가량에서 최대 강도를 보였다. HPMC의 분자량이 증가하거나, 물 양이 감소할수록 쌀 반죽의 압축강도 및 접착강도가 증가하는 결과를 보였다. 이들 인자 외에도, 셀룰로오스 에테르의 치환제 및 치환도도 쌀 반죽의 압축강도 및 접착강도를 결정하는 중요한 인자임을 확인하였다.

열처리가 강연사 제직 실크 직물의 기계적 성질에 주는 영향

박보경,엄인철,Park, Bo Kyung,Um, In Chul 한국섬유공학회 2017 한국섬유공학회지 Vol.54 No.4

Silk textile has been used for a long time owing to its soft texture and luster. However, its limited elasticity has restricted its textile application causing end users to demand silk textile with improved features such as good extensibility and elasticity. In this study, the silk textile was prepared with high twist silk yarn and subjected to heat treatments to augment its elasticity. The effect of heat treatment on the morphology and mechanical properties of silk textile was examined. As the water temperature and drying temperature increased, the shrinkage ratio of silk textile increased causing the weft silk yarn to become tangled. Further, the breaking strength of silk textile decreased and its elongation increased significantly. Most silk textiles, except the ones immersed in water and dried at $25^{\circ}C$, showed an elastic recovery of 100%. However, the results of tough repetitive extension tests (at 150% elongation condition) showed a small permanent extension of silk textile at the end of the first extension cycle.

습윤처리 및 열압착처리가 기계적으로 제작된 천연 실크 부직포의 구조 및 성질에 주는 영향

배연수,엄인철,Bae, Yeon Su,Um, In Chul 한국섬유공학회 2018 한국섬유공학회지 Vol.55 No.6

This study investigates the effects of wet and hot press treatments on the structure and mechanical properties of natural silk non-woven fabric under two post-treatment conditions: (a) hot press without wet treatment and (b) hot press with wet treatment. With respect to the fabric structure, a hot press without wet treatment does not alter the arrangement of silk filaments, while a hot press with wet treatment causes wrinkles in the fabric, and further bending of the silk filaments as the temperature is increased. With respect to the fabric mechanical properties, there is no improvement observed in the first condition, while the tensile strength of the fabric remarkably increases in the second condition when the hot press temperature is increased up to $200^{\circ}C$, indicating the crucial swelling of sericin by wet treatment to bind silk filaments. However, at a hot press temperature reaching $230^{\circ}C$, tensile strength decreases due to the molecular degradation of sericin. Moreover, hot press significantly decreases the porosity of the natural silk non-woven fabric with the wet treatment further accelerating the effect.

히드록시프로필 메틸셀룰로오스 첨가에 의한 쌀국수 제면성 연구 (I)

유영진,강미영,엄인철,Yoo, Young-Jin,Kang, Mi-Young,Um, In-Chul 경북대학교 농업과학기술연구소 2012 慶北大農學誌 Vol.30 No.2

본 연구에서는 쌀국수를 제조하기 위하여 히드록시프로필 메틸셀룰로오스 (HPMC)가 사용되었고, 물 첨가량, HPMC 첨가량, HPMC의 점도가 쌀반죽의 제면성이 주는 영향에 대한 연구가 수행되었다. 물 첨가량이 증가함에 따라 첫 번째 롤러를 통과한 쌀반죽의 형태가 더 반듯하고 균일한 형태를 나타내었다. 그러나, 물 첨가량이 특정 범위를 넘어서자, 제면 후의쌀국수의 형태가 굴곡이 심한 문제가 있었다. HPMC 첨가량을 달리하여 제면성을 살펴본 결과, 3% 함량이 쌀반죽의 우수한 제면성을 위해 최적의 조건임이 확인되었다. HPMC의 점도가 감소할수록 롤러를 통과한 쌀반죽이 불균일해지는 문제가 있었으나 점도가 가장 낮은 PMC 40H를 첨가한 경우, 높은 물 첨가량에서도 제면 후 면의 형태가 곧은 형태가 나타나 제면성이 향상되었음을 알 수 있었다. 전체적으로 본 연구에서 실험한 범위에서는 56~58%의 물첨가량, 3% 함량의 HPMC 첨가, 고점도 HPMC(PMC60U) 사용이 가장 우수한 제면을 위한 최적의 조건으로 생각된다. In this study, hydroxypropyl methylcelluloses (HPMCs) were added to prepare the rice noodle and the effects of water dosage, HPMC content, and viscosity level of HPMC on the noodle-making properties of rice dough were examined. As the water dosage was increased, the rice dough after roller pass became more flat and homogeneous. However, when the water dosage was over a certain range, the rice noodle became more waved. In the test result of various HPMC contents, 3% HPMC addition was turned out to be an optimum condition for the best noodle-making properties of rice dough. As the viscosity level of HPMC decreased, the rice dough after roller pass became inhomogeneous. However, the lowest viscosity level HPMC (PMC 40H) did not show any waved rice noodle at even high water dosage indicating the improved noodle-making properties of rice dough. On the whole, it seems that 56~58% water dosage, 3% HPMC content, and high viscosity HPMC (PMC60U) were the optimum condition for preparation of good rice noodle.

실크단백질 블렌드의 응용

박영환(Young Hwan Park),엄인철(In Chul Um),기창석(Chang Seok Ki),백두현(Doo Hyun Baek) 한국고분자학회 2005 고분자 과학과 기술 Vol.16 No.5