丝素蛋白在离子液体中的溶解特性研究

Dissolution of silk fibroin with ionic liquid as solvent

文章以离子液体为溶剂,研究了丝素蛋白在离子液体中的溶解特性。首先研究了丝素蛋白在不同结构的离子液体1-烯丙基-3-甲基咪唑氯化物([AMIM]Cl)和1-丁基-3-甲基咪唑氯化物([BMIM]Cl)中的溶解速率和溶解度。结果发现,相同条件下,丝素蛋白在[AMIM]Cl中具有较快的溶解速率和较大的溶解度;随温度的升高,溶解速度加快,合适的温度为95～105℃;随着丝素蛋白浓度的增大,相同条件下丝素蛋白在离子液体中的溶解速度减慢。XRD结果表明,丝素蛋白的非晶相部分首先被溶解,晶相部分结构被破坏后与溶剂作用逐渐被溶解。采用粘度法测定了丝素蛋白分子质量随溶解时间和温度的变化,结果表明:随加热时间增加和温度升高,蛋白质分子质量减小。为保证丝素蛋白的稳定性和溶解速率,温度一般控制在100℃以下,溶解时间小于5 h。

The solubility and the dissolution rate of silk fibroin in two ionic liquids, [ AMIM ] CI and [ BMIM ] Cl,were investigated respectively. It indicates that the solubility and dissolution rate of silk fibroin in [ AMIM ] C1 arc higher than that in [ BMIM ] C1. The dissolution rate of silk fibroin in ionic liquids increased largely with increasing the temperature and the proper temperature was 95 - 105 ℃. Contrarily, the dissolution rate decreased largely with increasing the concentration of silk fibroin. XRD test shows that, the amorphous phase of silk fibroin is dissolved firstly, and then the structure of crystal phase is destroyed and dissolved. The molecular weight （Mw ） of regenerated silk fibroin decreased with the increase of dissolution time and temperature from the result of viscosity. To assurance the Mw and dissolution rate,the proper condition should be at about 100 ℃ within 5 hours.