Fabrication of organic silk fibroin/multiwalled carbon nanotube composite cryogels by freeze-drying method

The multiwalled carbon nanotubes (MWCNTs) incorporated organic silk fibroin cryogels were fabricated through sol-gel process of aqueous silk fibroin solution, followed by freeze-drying. The MWCNT incorporated silk fibroin hydrogel was prepared by the regeneration of silk fibroin using an aqueous silk fibroin solution in which MWCNTs were dispersed by in-situ methods. The morphology and microstructure of the silk fibroin network structure were characterized using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The FESEM and TEM images show that the cryogels had three-dimensional network structures and the MWCNTs were well embedded in the network structures of regenerated silk fibroin. The porous properties of the MWCNT incorporated silk fibroin cryogels were investigated by nitrogen adsorption-desorption technique. The MWCNTs increased the proportions of micropores and mesopores in the silk fibroin cryogels when they were introduced in the appropriate amounts.