Patent ID: 7794634

Claim:
A method for producing nanotubes and compound nanofibers with core-shell structure from electrified coaxial jets, comprising the steps of: forcing a first liquid through a first electrified capillary tube to form a Taylor cone at the exit of the first electrified capillary tube, from whose vertex a very thin jet is issued having a flow rate ranging between 0.1 and 10000 microliters per hour; and forcing a second liquid, immiscible or poorly miscible with the first liquid, through a second capillary tube, wherein the second capillary tube is located inside the first electrified capillary tube and is approximately concentric with it, wherein the second liquid forms an almost conical meniscus, anchored at the exit of the second capillary tube, inside of the Taylor cone formed by the first liquid, wherein a jet of the second liquid, having a flow rate ranging between 0.1 and 10000 microliters per hour, is issued from the vertex of the conical meniscus of the second liquid, wherein the jet of the second liquid flows simultaneously and inside of the extremely thin jet of the first liquid, forming an extremely thin compound jet in which both liquids flow coaxially, wherein the second capillary tube can be at the same or different electric potential than that of the first electrified capillary tube and the potential difference between one of the two electrodes and the grounded electrode ranges between 1 V and 100 kV, wherein the menisci and the coaxial jet can form in a dielectric atmosphere, in a bath of a dielectric liquid, or in vacuum, wherein the compound jet comprises an inner core formed by the second liquid and an outer layer or coating formed by the first liquid, and the outer diameter of the compound jet has a diameter between 300 microns and 5 nanometers, and wherein the first liquid (that which flows on the outside) undergoes a phase change from liquid to solid, in such a way that the time needed for the phase change (solidification) of the first liquid is comparable or smaller than the residence time of the first liquid in the coaxial jet.