Preparation And Structure Of Size Controllable Polypeptide Particles From Wool Fibers

Wool proteins abundantly consisted of keratins are of great potential in textiles industry and biomedical fields for their intrinsic performance. However, there are many wool fibers discarded due to the limitations of spinning short wool fibers into yarns during the spinning process. Therefore, concerning for renewable resources and environmental protection, wool fibers can be dissolved and reused as multifunctional materials. Size controllable polypeptide particles from wool fibers were prepared by conversion of alkaline and acid, filtration, dialysis and finally extraction.Through this method, to obtain the stabilized polypeptide solution, the concentration of sodium hydroxide and dissolved time of wool fibers were investigated. It was obvious that particle size and morphology could be controlled by changing the concentration of sodium hydroxide and dissolved time. Moreover, the conformation of molecular chains was changed through the addition of acid. The polypeptide solution was presented the colloid properties with Tyndall effect. TEM displayed that the sizes of most spherical particles were around 50 nm treated by 3% wt sodium hydroxide. Zeta potential results indicated that the polypeptide solution possessed good chemical stability.Various characterization methods were adopted to understand the structure and performance of polypeptide particles extracted from the solution. On the microscopic level, the particles were with spherical shapes and clear outlines.From the FTIR analysis, obtained nanoparticles showed the characteristic peaks of peptides. Combined with XPS analysis, although the intense action of alkali, the particles maintained the complete structures of polypeptides.X-ray diffraction results indicated thatalkali destroyed some parts of crystalline region of particles.Compared with wool fibers, the thermal properties were declined.In addition, basing on the research foundations of composites, polyurethane were recombined to polypeptide particles to control the size and morphological structures. The micropores in the polyurethane provided the mould for the particles and changed the size and morphologies of particles. Meanwhile, most characterization results implied that the addition of particles changed slightly the inter structures of composite membrane. Therefore, this method will have profound scientific significance on the research of other applications such as biotechnology and pharmaceutical fields.