Wool, Silk/Ionic Liquid Solution Properties And Morphology Of Aggregation Study

Wool and silk as important nature protein fibers could be used in the preparation ofthe matrix material such as regeneration fiber, medical materials, physiologicalmembrane materials besides used for textile fiber. Nowadays, the research of regeneratedwool and silk after their dissolved is popular. Studies of protein solution properties andaggregation morphology on the application of wool and silk has a crucial significance.In this paper, ionic liquid used as the solvent of wool and silk, we preparedprotein/ionic liquid solutions and explored the effect of different solution factors. Westudied the rheology and the gathered form in solution of WK(wool keratin)/ionic、RSF(room silk fibroin)/ionic. Specific studies as follows:1．Four ionic liquids:[Bmim]Ac,[Bmim]Cl,[Amim]Cl,[Bmim]Br weresynthesized for dissolving wool and silk. The results show that [Bmim]Ac has thestrongest ability to dissolving wool and silk, the rate of dissolution is faster and massfraction became greater with the temperature increased.The SDS-PAGE results showthat:when temperature elevated, the low molecular weight of WK, RSF increases, themolecule weight distribution of WK was polydispersity and intermittent; the moleculeweight distribution of RSF was continuous and polydispersity.2．The rheology of WK, RSF/ionic liquid solution be studied. The results ofsteady-state rheology and dynamic rheology of WK/ionic liquid show: WK/ionic liquid isfrom near newton fluid transition to pseudoplastic fluid with mass fraction increased. Theviscosity of WK/ionic liquid is sensitive to temperature, the viscous flow activationenergy Eηis high in low temperature and low in high temperature. WK/Ionic displayedviscosity characteristics at stress range from0to100Pa，strain from20%to200%. SAOS results show that the Modulus of elasticity(G’) may exceed the viscousmodulus(G’’) to exhibit solid-like characteristics when frequency or WK massfraction is increasing. The solution have the gel point. The studies of steady-staterheology and dynamic rheology of RSF/ionic liquid show: the RSF/ionic liquidsolution is pseudoplastic fluid. The non-newtonian index of solution would be reduced asmass fraction and temperature increased. Eηwould be reduced as the mass fraction ofRSF increased. In this study, the test frequency interval (0~65Hz) and concentrationrange(15~20%),the viscous modulus is always greater than modulus of elasticity,there isno gel point.3．Using small-angle X-ray scattering measurements to study WK,RSF’smicroscopic morphology gathered in ionic liquids, getting the message such as the radiusof gyration,the size distribution of particles and other information. In the SAXS patterns,there is no Bragg peak in the patterns,WK,RSF show weak and broad scattering peak.WK,RSF senior fine structure does not exist in solution. With the PRIMUS and GNOMsoftware calculated:the radius of gyration of WK in1%WK solution in11.37~12.3（±0.213）nm between; and the radius of gyration of RSF in1%RSF solution in10.8(±0.059)~13.56nmnm between.WK, RSF flattened spherical models found in the solution,the diameter of scattering particles was15nm,17.5nm.4．Study wool,silk and the role of ionic using fluorescence spectroscopy. Theresults of fluorescence spectroscopy show: ionic liquid as quencher on endogenousfluorescence amino of wool and silk. Protein unfolding effects occur and spiral or foldedstructure is destroyed, resulting in its dissolution.