Straining flow spinning: Simplified model of a bioinspired process to mass produce regenerated silk fibers controllably. (December 2017)

• Record Type: Journal Article
• Authors: Madurga, Rodrigo; Guinea, Gustavo V.; Elices, Manuel; Pérez-Rigueiro, José; Gañán-Calvo, Alfonso M.
• Is Part Of: European polymer journal. Volume 97(2017)
• Page Start: 26
• Page End: 39
• Publication Date: 2017-12
• Subjects: Regenerated fibers -- Fibroin -- Biomimetic -- Silk; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2017.09.037
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Detail of the capillary-nozzle arrangement in Straining Flow Spinning and flow of the dope at the capillary outlet. Highlights: SFS allows spinning regenerated fibers using two interacting coaxial fluid streams. SFS processes are controlled by geometrical, hydrodynamic and chemical parameters. SFS allows spinning at ambient temperature from aqueous dope and mild coagulants. A model for the draw ratio of the process and the diameter of the fibers is validated. Abstract: This paper describes a method of molecular self-assembly by using two interacting streams for the production of bioinspired and biocompatible fibers. A first stream of an aqueous solution (dope) of polymer molecules (fibroins) is extruded from a capillary. The end of the capillary is surrounded by a focusing fluid which is miscible with the dope solution. The interaction between the dope solution and the surrounding focusing fluid, which can be an environmentally friendly solvent like ethanol or a water-based solution, leads to hydrodynamic stretching of the dope and allows molecular diffusion processes between the fluids to be established. Polymer molecules within the solution at stretched regions of the jet interact and self-assemble, forming a fiber which could be wound onto a mandrel. This work provides an exhaustive description of the geometrical and hydrodynamic conditions required to achieve the optimum interaction which triggers the formation of fibers. A simplified theoretical model that accounts for the influence of the main parameters of the process on the fibers is also given and experimentally validated.