In order to improve the spinning efficiency, the spinning experiments with cellulose/1-butyl-3-methylimidazolium chloride solution were done whilst increasing spinning speed. It was found that the tenacity and initial modulus of regenerated cellulose fibers increased but the elongation at break decreased slightly with increasing spinning speed at constant draw ratio. Further, the synchrotron wideangle X-ray diffraction and small-angle X-ray scattering were carried out to illustrate the relationship between the structure and the mechanical properties. It was shown that the crystal orientation, crystallinity, amorphous orientation factor as well as orientation of the microvoids along the fiber increased with the spinning speed as the diameter of the microvoids in the fiber decreased. From the analysis of the spinline stress, it is clear that the spinline stress increased when both extruding and draw speed increased at constant draw ratio. This resulted in the improvement of supramolecular structure and mechanical properties of the regenerated cellulose fibers.

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Concentrated cellulose/1-butyl-3-methylimidazolium chloride ([bmim]Cl) solution which exhibits typical elasticity has been employed to prepare fibres by dry jet wet spinning technique. In order to design the spinneret, simulation on contraction flow of cellulose/[bmim]Cl solution through spinneret orifice was carried out. Geometry and mathematical models were established according to rheological behaviour and material parameters. The effects of geometry on variation of viscosity and flow pattern were simulated and discussed. The results show that an increase in aspect ratio decreased the apparent viscosity and a decrease in entrance angle reduced the size of 'dead' region. The aspect ratio and entrance angle of spinneret during dry jet wet spinning were optimised.

Cellulose/silk blend solutions were prepared in 1-butyl-3-methylimidazolium chloride [BMIM]Cl and films were subsequently formed from coagulation baths. Fourier Transform Infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD) and scanning electron microscope (SEM) were carried out to compare the influence of coagulation agents on the weight content of silk fibroin (wSF), secondary structure and morphology of cellulose/silk blend films. Rough and scaly films were formed due to rapid crystallisation induced by ethanol. When films were coagulated in acetonitrile, a change from random coil to b-sheet structure of silk fibroin and from cellulose I to cellulose II of cellulose occurred favourably. When blend films were coagulated in water, there was a protein component extraction which diffused into the coagulation bath.