Rapid and efficient fabrication of multilevel structured silica micro-/nanofibers by centrifugal jet spinning

A rapid and efficient method consisting of two simple steps, centrifugal jet spinning (CJS) and annealing, is introduced to fabricate multilevel structured silica micro-/nanofibers. Using this technique, which is 500 times faster than electrospinning, silica micro-/nanofibers with a hollow or porous internal structure are formed as a result of non-solvent evaporation induced phase separation in the spinning solution. Silica nanofibers with solid cross sections (364 nm and 781 nm), hollow cross sections (outer and internal diameters of 458 nm and 216 nm respectively), and encapsulated voids (outside diameter of 1.4 μm where bi-continuous nano-pores 118 nm are observed) are fabricated by tuning the amount of non-solvent in the spinning solutions. This technique can be readily extended to large-scale and efficient fabrication of various ceramic materials with multileveled fibrous structures.