Fibroin artificial spinning

Pioneering work in fibroin wet spinning can be traced back to 1930s. After that, little work has been done until the late 1980s, when more research was done to investigate the spinning dope systems, and structure and properties of the artificial fibroin silk. The composition of the dope is very important to the properties of the final fiber. Several kinds of solvents, such as LiBr—EtOH, Ca(NOo,)2—MeOH, formic acid, HFIP, hexafluoro acetone (HFA), and so on, are used to prepare the spinning dope (Table 4). Very recently, an ionic liquid was used as dope solvent (Phillips et al., 2005). 

Yao, J.M., Masuda, H., Zhao, C.H., and Asakura, T. "Artificial spinning and characterization of silk fiber from Bombyx mori silk fibroin in hexafluoroacetone hydrate". Macromolecules 35(1), 6-9 (2002). 

The overall performance difference between the artificial fibroin silk and natural silk is induced by many factors. Composition of the spinning dope is critical but not the only factor. Important to understand is that the spinning process which determines the condensed structure of silk is crucial. It suggest that knowing the spinning process details it should be feasible to produce high-performance silk artificially and "design" silk. 

From a scientific perspective, the artificial silk experiments have provided insight into the morphology of reconstituted silk. In the spinning dope, fibroin molecules adapt a random coil or other less extended conformations. 

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