Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano, Japan.
Int J Biol Macromol. 2012 Mar 1;50(2):337-47. doi: 10.1016/j.ijbiomac.2011.12.006. Epub 2011 Dec 19.
In this study, silk sericin nanofibers from sericin hope-silkworm, whose cocoons consist almost exclusively of sericin were successfully prepared by electrospinning method. Scanning electron microscopy (SEM) was used to observe the morphology of the fibers. The effect of spinning conditions, including the concentration of sericin cocoon solution, acceleration voltage, spinning distance and flow rate on the fiber morphologies and the size distribution of sericin nanofibers were examined. The structure and physical properties were also observed by Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TG). The optimum conditions for producing finely thinner fibrous sericin nanofibers without beads were the concentration of sericin solution above 6-8 wt%, acceleration voltage ranging from 25 to 32 kV, spinning distance above 9 cm, and flow rate above 0.06 cm min(-1). The mean diameter of as spun sericin fibers varied from 114 to 430 nm at the different spinning conditions. In the as-spun fibers, silk sericin was present in a random coil conformation, while after methanol treatment, the molecular structure of silk sericin was transformed into a β-sheet containing structure. Sericin hope nanofiber demonstrated thermal degradation at lower temperature than the sericin hope cocoon, which probably due to the randomly coiled rich structure of the sericin hope nanofiber.
在这项研究中，成功地通过静电纺丝法制备了来自丝胶蚕茧的丝胶纳米纤维，其蚕茧几乎完全由丝胶组成。扫描电子显微镜（SEM）用于观察纤维的形态。研究了纺丝条件，包括丝胶茧溶液的浓度、加速电压、纺丝距离和流速对纤维形态和丝胶纳米纤维的粒径分布的影响。还通过傅里叶变换红外（FT-IR）、差示扫描量热法（DSC）和热重分析（TG）观察了结构和物理性质。在没有珠粒的情况下生产更细的纤维状丝胶纳米纤维的最佳条件是丝胶溶液浓度高于 6-8wt%，加速电压范围为 25-32kV，纺丝距离高于 9cm，流速高于 0.06cmmin(-1)。在不同的纺丝条件下，初生丝胶纤维的平均直径从 114nm 变化到 430nm。在初生纤维中，丝胶呈无规卷曲构象，而在甲醇处理后，丝胶的分子结构转变为含有β-折叠结构的构象。丝胶希望纳米纤维的热降解温度低于丝胶希望茧，这可能是由于丝胶希望纳米纤维的无规卷曲丰富结构所致。
