Controllable synthesis of microscale titania fibers and tubes using co-laminar micro-flows

Abstract

This article reports a new working system and a novel approach for the continuous fabrication of microscale titania 1D materials in co-axial microdevices using co-laminar microflows in situ to form a template. Two miscible ethanol solutions of polyvinyl butyral and titanium alkoxide were applied to ensure the formation of multiphase co-laminar flows in microfluidic devices. Titanium alkoxide caused the gelation of the PVB solution at the interface, which leads to the formation of a gel tube with the remaining titanium alkoxide trapped inside. Titania 1D materials were obtained after calcinations. Both fibers and tubes could be fabricated via the proposed synthesis scheme by controlling the microchannel structure and the flow parameters. The crystalline structure of the products could be controlled by the sintering time. The specific area of the products could be adjusted by changing the composition of the titniaum alkoxide solution.