DISSOLUTION AND REGENERATION OF COLLAGEN FIBERS USING IONIC LIQUID

摘要

Due to the triple-helical structure and the strong inter- and intro-molecular forces including van der Waals bonds, hydrogen bonds, hydrophobic bonds, ionic bonds (interactions between oppositely charged residues)on side chain, skin collagen has very stable structure and is extremely hard to dissolve in common solvents. Ionic liquids have strong capability to destroy the hydrogen bonds and can be used to dissolve various natural polymers, e.g. cellulose, chitin, silk and starch. In this paper, native skin collagen fibers were successfully dissolved in the ionic liquid, 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), and regenerated in different precipitators. The observation by polarized optical microscopy showed that the crystal structure of collagen fibers had been destroyed by [BMIM]Cl during the heating (Fig. 1). Temperature-dependent FTIRwas applied to detect the structural change of collagen/[BMIM]Cl during dissolving. The structure of regenerated collagen was characterized by FTIR and XRD. It showed that the triple helical structure of collagen had been partly destroyed during the dissolution and regeneration. The film forming ability and the thermostability of the regenerated collagen was highly dependent on the precipitating treatment. The possible mechanisms of dissolving of collagen in [BMIM]Cl and the regeneration in the precipitators have been proposed. The collagen/cellulose composite with different forms (film, fiber, gel) can be successfully prepared by using [BMIM]Cl as medium. This work was supported by the National Natural Science Foundation of China (20604026).