• 한국잠사곤충학회지
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• 제37권2호
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• pp.142-153
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• 1995

특이한 분자 구조를 가진 생체 고분자로서 유용한 견 피브로인은 다양하게 성형 가공할 수 있으며 이를 위해서는 견 피브로인 수용액을 필요로 한다. 견 피브로인의 용해 조건이 형성되는 견 피브로인의 분말과 필름에 미치는 영향을 알아보기 위하여 종성염과 산가수분해법으로 견 피브로인을 용해시킨 수용액으로부터 견 피브로인 분말과 필름을 제조하고 이들의 특성을 아미노산 조정 분석, SEM, DSC, IR, X-ray Diffraction 등의 방법을 통하여 조사 분석한 결과는 다음과 같다. 1. 염화칼슘법과 염산법에 의해 피브로이을 용해시켰을 때 처리에 따라 아미노산 조성은 달랐으며 분자량도 차이가 있었다. 2. 분말의 구조 분석 결과, 염화칼슘법에 의한 처리에서 열분해 온도는 대조에 비해 낮게 나타났고 무정형의 분자 구조를 띄고 있음을 알 수 있었다. 염산 처리에 의한 잔유물은 대조보다 높은 온도에서 $\beta$구조에 의한 분해 거동을 보였으며 높은 결정화도를 나타냈다. 한편 염산에 용해된 부분은 열분해 분석 결과 a-helix에 의한 흡열 peak을 나타냈다. 3. 염화칼슘법에 의해 형성된 견 피브로인 필름은 모정형에 가까운 결정 구조를 가지고 있지만 불용화 처리에 의해 결정성이 향상됨에 따라 피브로인 필름의 흡습율은 감소하였으며, 열분해 온도가 증가했다.

• 한국잠사곤충학회지
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• 제43권1호
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• pp.41-48
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• 2001

The purification, dissolution and powdering of stained waste silk obtained from weaving and dyeing process were studied for the surface modification of textile fabric and plastic materials. The whiteness of stained waste silk could be improved through degumming and bleaching with sodium hydrosulfite. The water-soluble fibroin solution can be obtained by dissoving the degummed waste silk in a boiling solution of 50% calcium chloride for 60 minutes. The salts and heavy metals contained in fibroin solution were removed by electric dialysis, wool fiber filtration and gel filtration chromatography. The fibroin powder was prepared by using a fine grinder after the alkali treatment for weakening the silk fiber. The fine fibroin powder of particle size around 30 ㎛ was obtained with a ultra fine-mill, while it was finer below 10 ㎛ with a ball-mill. The dissolved or powdered silk was applied to the surface of fabric with addition of the binder (a urethane resin). The moisture content of polyester and nylon fabrics treated with the silk solution was improved due to hygroscopic property of silk. The fine fibroin powder mixed with the binder ws coated on the surface of synthetic film by use of the air pressed sprayer. It was revealed that the hygroscopicity as well as the softness of fibroin powder coated film was much improved. Therefore, it is thought that the fine silk fibroin powder is applicable as an coating agent for the surface modification of plastic and synthetic leather.

• 대한의용생체공학회:의공학회지
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• 제43권4호
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• pp.251-258
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• 2022

Silk fibroin microparticles were fabricated using a phase separation technique between silk fibroin solution and polyvinyl alcohol. We found that the concentration of polyvinyl alcohol determines the size of microparticles. The mean diameter of the silk fibroin microparticles varied from 3.48 ㎛ to 4.05 ㎛. The silk fibroin microparticle size increased as a function of the concentration of PVA in aqueous silk solution. The resulting silk fibroin microparticles have narrow size distribution (i.e. monodisperse) and smooth/spherical surface. Also, we studied the effects of mouse serum, sodium phosphate buffer (PBS), and pH on the stability of the silk fibroin microparticles. Overall, we demonstrated the simple method to fabricate and to control the silk fibroin microparticles that makes our silk microparticles to be usable for a potential drug delivery carrier.

• Macromolecular Research
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• 제16권7호
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• pp.604-608
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• 2008

Color dye-doped silk fibroin nanoparticles were successfully fabricated using a microemulsion method. An aqueous silk fibroin solution was prepared by dissolving cocoons (Bombyx mori) in a concentrated lithium bromide solution followed by dialysis. A color dye solution was also mixed with the aqueous silk fibroin solution. The surfactants used for the microemulsion were then removed by methanol and ethanol, yielding color dye-doped silk fibroin nanoparticles, approximately 167 nm in diameter. The secondary structure of the nanoparticles showed a $\beta$-sheet conformation, as characterized by Fourier transform infrared spectroscopy. The morphology of the nanoparticles was determined by field emission scanning electron microscopy, transmission electron microscopy and atomic force microscopy, and their size and size distribution were measured by dynamic light scattering. The color dye-doped silk fibroin nanoparticles were examined by confocal laser scanning microscopy.

• 한국잠사곤충학회지
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• 제39권1호
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• pp.56-61
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• 1997

The silk fibroin solution was prepared and applied to the surface of fabrics for the purpose of weighting as well as a surface modification. The water-soluble fibroin solution can be obtained by dissolving the cocoon fibroin in a boiling solution of 50% calcium chloride for 60 minutes. For the fixation of a water soluble fibroin onto the fabric surface, the various methods were investigated. The fixation can be achieved on a silk fabric by the after treatment with ethanol, stannous choride and methacrylamide. On the other hand, the epichlorhydrin compound is the most promising fixation agent for a cotton fabric. As a result of the examination of property changes, the softness and crease recovery were lessened for a silk crepe fabric by treating with 1-2% fibroin solution, while those properties were improved for a silk knit fabric.

• 한국염색가공학회지
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• 제6권1호
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• pp.62-70
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• 1994

Silk fibroin was dissolved in 9.3 M LiBr aqueous solution at 4$0^{\circ}C$ for 1 hour. The dissolved silk fibroin was regenerated by casting the dialyzed solution into the membrane. The freshly prepared silk fibroin membrane was soluble in water and was. mainly consisted of random coil conformation. By the treatments in saturated water vapor at 3$0^{\circ}C$ and in 75% ethanolic aqueous solution (V/V), the insoluble membranes were obtained and the structure and morphology of those were investigated for the structure by means of X-ray diffraction analysis, infrared spectroscopy, thermal analysis. Rheovibron and scanning electron micrograph. Silk II type crystals were obtained by treating amorphous silk fibroin membrane in the random coil conformtion with 75% ethanol solution(V/V). Crystallization to silk II type crystals occured even after a few minutes, and a large number of silk II type crystals were formed after 30 mins. On the other and, the membrane treated in saturated water vapor was composed of the mixtures of silk I and silk II type crystals. A large number of silk I and silk II type crystals were formed after 24 hours. The micro brownian motion in the amorphous regions of silk fibroin membrane started at about 175~185$^{\circ}C$. $\alpha$ dispersion appeared at about 20$0^{\circ}C$ in the amorphous membrane, and at about 22$0^{\circ}C$ in the crystalline membrane. The crystallization of random coil conformation to silkII type crystals occured at about 215$^{\circ}C$. The surface, bottom and cross-section of the membranes were observed by scanning electrom microscope. Fine forms alike spherulites appeared at the surface of crystalline membrane.

• International Journal of Industrial Entomology and Biomaterials
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• 제20권2호
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• pp.99-105
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• 2010

In this paper, the regenerated silk fibroins were dissolved in LiBr aqueous solution with different dissolution temperature and time, and the effects of the dissolution condition on the regeneration yield, molecular weight, wet spinnability, and electrospinnability of regenerated silk fibroin were investigated. The regeneration yield, molecular weight distribution, and wet spinnability of regenerated silk fibroin were nearly affected by the dissolution temperature and time. However, the electrospinning performance of silk fibroin was influenced by the dissolution condition implying the electrospinning of silk fibroin is more sensitive process than the wet spinning in the range tested in this study. While $25^{\circ}C$ of dissolution temperature resulted in a good electrospinnability of regenerated silk fibroin, the electrospinnability was slightly deteriorated when silk fibroin was dissolved at $60^{\circ}C$ for 6 hours. Also, though the fiber diameters of electrospun silk fibroin produced by the dissolution at $25^{\circ}C$ for 6 hours and 24 hours were 443 and 451 nm, respectively, that at $60^{\circ}C$ for 5 min was reduced to 411 nm. The fiber diameter was more decreased to 393 nm when the dissolution time increased up to 6 hours at $60^{\circ}C$.

• 한국잠사곤충학회지
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• 제41권1호
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• pp.41-47
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• 1999

중성염에 용해한 후 얻어진 견피브로인 수용액의 pH를 3.0으로 조정하였을 때 피브로인 분자쇄들간에 정전기적 반발력이 감소하여 피브로인 분자쇄 상호간에 결합력이 증가하므로 겔화시간이 단축되었고 적외선분광분석 결과 ${\beta}$-sheet 구조로의 전이가 빨리 일어나고 있음을 확인하였다. 2. Silk fibroin 용액내에 glycerol 함량비가 클수록 겔화의 시간은 크게 단축되었으나 상대적인 수분함량의 증가로 강도는 낮아졌다. 3. Silk fibroin 용액내에 피브로인의 농도가 높을수록 겔의 강도는 낮아졌다. 4. 효소분해된 Silk fibroin 용액을 pH3.0으로 조정 후 실온에서 보관하였을 때 분자량저하에 따른 분자쇄간 결합력 약화로 겔상을 이루지 못하고 흰색의 분말상 침전을 형성하였으나 pH 3.0 조정 후 원심분리하면 겔상을 얻을 수가 있었다. 5. 시차주사열분석결과, 견피브로인 수용액을 등전점 조절하였을 때에는 재결정화에 의한 발열피크가 나타나지 않았고 결정성이 좀더 높았으며 효소처리한 경우에는 분자량감소로 낮은 온도 부근에서 일부 열분해가 일어났으나 저분자화된 분자쇄들이 새로운 결합을 형성하여 열적안정성이 다소 높게 나타났다.

• Fibers and Polymers
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• 제2권2호
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• pp.58-63
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• 2001

Silk fibroin (SF) was dissolved in calcium chloride/ethanol/water mixture(1/2/8 in mole ratio) at $70^{\circ}C$ for 4h. The dissolved silk fibroin was regenerated by casting the dialyzed solution into films. The films were treated with 50% aqueous solution of methanol for different times, and their antithrombogenicity was evaluated by in vivo tests. In vivo blood tests were made by a method of peripheral vein indwelling suture. It was found that the silk fibroin had a good antithrombogenicity and an absorbability even though the polymer showed foreign body reaction. Finally, the blood compatibilty of silk fibroin films which were subjected to structural change by the methoanl treatment, was examined in connection with their interfacial surface energy, and a correlation between these properties was found to be present.

• 한국잠사곤충학회지
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• 제35권1호
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• pp.60-68
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• 1993

견층을 자연 건조하므로써 변성을 받지 않은 시료에 대하여 Bacillus licheniformis 단백질 분해 효소 정련과 비누 정련의 특성을 비교하기 위하여 널리 사용되고 있으며 용해할 때 비교적 피브로인에 대한 degradation이 적은 두가지 용해볍으로 용해한 견 피브로인 수용액에 대하여 분자 구조상의 차이가 있는지를 구명하고져 실험한 결과는 다음과 같다. 1. 견 피브로인 수용액의 편광 현미경으로 관찰한 결과 구정은 관찰되지 않았으나 나뭇잎 모양의 피브릴 구조가 나타났고 전자 현미경으로 관찰한 결과 구정의 크기는 30~120mm 정도였으며 정련 방법과 견 피브로인을 용해하는 방법에 따른 차이는 없었다. 2. 견 피브로인 수용액의 점도 측정 결과 비누 정련견 피브로인 수용액보다 효소 정련 견 피브로인 수용액의 intrinsic viscosity가 낮았다. 3. 견 피브로인 수용액에 대한 전기 영동 시험 결과 약 20kd에서 small submit와 50kd 이상에서 large subunit에 해당하는 폭 넓은 band가 나타났으며 정련 방법에 따른 차이는 없었다. 4. 견 피브로인 수용액을 냉동 건조한 분말에 대한 열 분해 온도는 비누 정련 견사와 효소 정련 견사간에 차이가 없었고 용해 방법에 따른 열 분해 온도는 cupric hydroxide-ethylene diamine법으로 용해하였을 때 조금 낮았다. 5. 견 피브로인 수용액을 송풍 건조한 시료에 대한 IR spectrum은 silk II형과 silk I형이 복합되어 나타났으며 정련 방법은 다른 차이가 없었다.