Roles of Coaxial Spinneret in Taylor Cone and Morphology of Core–Shell Fibers

This paper reports on the roles of three coaxial spinnerets with different electric field distributions, including retracting spinneret, flat spinneret, and protruding spinneret in the Taylor cone, jet motion, and resultant core–shell fibers. The Taylor cone, jet motion, and the morphology and internal structure of resultant core–shell fibers for these three above-mentioned spinnerets are systematically studied. The results show that the Taylor cone, jet motion, and core–shell fiber morphology are influenced by the electric field distribution induced by different spinneret structures. The retracting spinneret produces a thinner fiber with groove morphology due to the shorter straight jet length, larger envelope angle and higher whipping frequency. On the contrary, the protruding spinneret causes coarser and porous morphology fibers because of the longer straight jet length, smaller envelope angle, and lower whipping frequency. The jet motion has a tremendous influence on the fiber diameter and surface morphology; in addition, the internal structure of core–shell fiber is affected by the morphology of the Taylor cone.