An aerogel with dendritic fibro-structure could be produced from a dilute aqueous solution of liquid silk, and the structure of the aerogel was analyzed using Raman spectroscopy. A weak molecular orientation was recognized in the portions of the aerogel with dendritic fibro-structure, and the gel contained β-sheet conformation. The β-sheet modification was promoted by the water annealing treatment at room temperature. The modification proceeded more markedly in the regions with molecular oriented texture.
The extra-fine filament is size of cocoon filament below 2.0 denier in silkworm. "Hakugin" is known as the extra-fine filament silkworm race. However, in recent years, because the size of “Hakugin” cocoon filament is becoming thicker, the development of silkworm races has been required in order to maintain its extra-fine filament. And improvement for oviposition properties has been demanded from the viewpoint of silkworm eggs production. On the basis of parent strains of the “Hakugin”, we were grown new strains with improved properties of cocoon filament and oviposition, “C516 × C517”. As compared with Hakugin, this breed didn't change any of the fineness, yarn quality and so on. In addition, this breed, it was better the oviposition properties than “Hakugin”. “C516 × C517” was conducted a trademark registration nicknamed as "Hakurei".
We developed a device to measure the dynamic drapability of fabric, evaluating the swinging motion of silk fabrics. The relationship between revolution speed and amount of fabric displacement was investigated, along with the relationship between waveform and frequency; and the swinging motion was numerically evaluated. The results showed that, as the fabric revolution speed increased, the drape dynamic coefficient increased, for all fabrics. The waveform and power spectrum shape also varied with the speed of revolution. The results also showed that the swinging motion could be numerically evaluated.
We analyzed the influence of silk reeling conditions on reeling tension. Our aim was to achieve low-tension production of raw silk by using a multipurpose silk reeling machine that could measure reeling tension continuously with a load cell sensor. Decreasing the silk reeling speed and increasing the cocoon cooking time and reeling water temperature effectively reduced the reeling tension. In addition, by simplifying the thread guide, we were largely able to decrease the reeling tension in comparison with that of a conventional silk reeling machine.
Here we show that functional molecules can be easily attached to azide-incorporated silk fibroin film by click reaction. The suppression of cell adhesion on fibroin film was achieved by the attachment of PEG chains by click reaction. On the other hand, the promotion of cell adhesion on fibroin film by the attachment of RGD peptides by click reaction was not successful in this study.
Silk spongy structures are produced by freezing a silk solution. To control the silk spongy structure formation, we investigated freezing temperature effects. Results show that lower freezing temperatures of silk solutions produce brighter silk spongy structures with smaller pore-sized surfaces. These results suggest that the freezing temperature is an important factor affecting silk sponge formation.
A hybrid silkworm (Nd × watako) was reared for sericin-rich cocoon development. The degumming loss of the cocoon was as high as 91%. The sericin protein, which is extractable merely using boiling water, was hydrolyzed slightly, but the molecular weight remained high at around 250 kDa. The extracted sericin was fabricated to sheets and an electro-spun fiber mat.
This paper discusses basic strategy in order to establish new legal structure in silk industry. Japanese Basic Agricultural Policy has changed in 1999, The Agricultural Basic Act was replaced Food, Agriculture and Rural Areas Basic Act. Respond to social needs, some promotion acts related to agricultural products have enacted,. New silk and silkworm industry need new promotion act that are based on Food, Agriculture and Rural Areas Basic Act and CSV (Creating Shared Value).