Directly obtaining high strength silk fiber from silkworm by feeding carbon nanotubes.

By feeding silkworm with the carbon nanotube, CNT, we directly obtained high strength silk fiber, SF, from silkworm. The CNT-based SF, SF/CNT, has a stress at 1.69GPa and a strain at about 24% both higher than those of the SF and are capable to compare with the super SF and even the spider fiber. Morphology comparison showed that the presence of CNT in SF caused the cross-section changed from triangle to ellipse. X-ray diffraction and infrared analysis indicated that the embedded CNT in SF caused an increase in silk-I structure. Specifically the amide-II structure reduced by about 5% and the amide-III structure increased by about 10%. Thermogravimetric analyses indicated that the presence of CNT in SF enhanced the thermal stability. Additionally, the presence of CNT in SF also enhanced the electrical property.