Method for producing elongated structures such as fibers from polymer solutions by straining flow spinning

Abstract

A method of molecular self-assembly is disclosed using two interacting streams that are allowed to interact and are subsequently forced through an orifice. A first stream of a dope solution of polymer molecules is extruded out of a capillary. The dope stream is surrounded by a focusing fluid which is miscible with the dope solution. The interaction between the jet of dope solution and surrounding focusing fluid creates hydrodynamic stretching and allows for extracting solvent from the dope solution. Concentrated polymers within the solution at stretched regions of the jet interact, and finally self-assembly takes place after the fluids are forced through the outlet of a converging nozzle. The formation of the structure can be optionally completed in a coagulating space. The structures thus obtained such as fibers or threads can be wound onto a mandrel.