Tunable silica nanofibrous structures in view of resolving challenging purification and separation obstacles

Abstract

Electrospinning of polymer nanofibers has been studied extensively and has shown to be possible via stable, reproducible and controllable processes. The development of more inert nanofibers with higher thermal and chemical resistance extends the application field towards challenging purification and separation obstacles of today. By direct electrospinning of a tetraorthosilicate (TEOS) based sol–gel solution, without a sacrificing carrier polymer, dense ceramic silica nanofibers can be produced. A humidity or temperature induced wettability-switch from highly hydrophobic after electrospinning to superhydrophilic makes the resulting silica nanofibrous membranes ideal for fast gravity-driven separation, especially upon tuning the surface chemistry and the functionalization. This is showcased for the separation of immiscible liquids and the photocatalytic degradation of organic micro-pollutants.