Fiber - Fiber of the Future

Introducing drops into a liquid continuous phase in the form of an emulsion, with a regular spatial arrangement of monodisperse drops, is currently difficult to realize. Existing approaches try to do this by passing the continuous phase through pipes or channels, but this prevents the formation of fibers. Although nanofibers with a core-shell structure can be produced using the electrospinning process, it is not possible to create a regular arrangement of inclusions and embedded objects (see e.g. Md. Fazley Elahi et al., Journal of Bioengineering & Biomedical Sciences 2013, Vol. 3, 1000121). Furthermore, these fibers usually do not have a cylindrical shape, but constrictions between the embedded objects are the result, which can be a disadvantage for some industrial applications. The present invention overcomes the problems mentioned above and introduces a process for producing regularly arranged droplets in a continuous liquid jet, whereby droplets and jet consist of different different liquids. A continuous jet and a regular stream of drops collide lying on a common plane and thus produce the regular arrangement of the drops embedded in the continuous jet. The functioning of the concept has been tested and verified on laboratory scale, successfully producing such liquid structures (see Planchette et al. Phys. Rev. Fluid 2018, Vol. 3, 0936). Furthermore, by curing the resulting liquid jet after drop inclusion, this process allows the subsequent production of fibers, especially cylindrical fibers with regularly arranged encapsulated objects. Curing has also been successfully tested on a laboratory scale with simple continuous beams using a sol-gel transition (see also C. W. Visser et al. Science Advances 2018, Vol. 4), allowing the production of solid fibers. The purpose of the prototype is thus to (i) realize in a single device (i) the generation of a continuous beam with regularly embedded monodisperse droplets, (ii) subsequently cure this beam, and (iii) receive the resulting cylindrical fibers, all steps being suitably controlled and monitored.