Electrospun flexible self-standing γ-alumina fibrous membranes and their potential as high-efficiency fine particulate filtration media

Abstract

Novel self-standing γ-alumina fibrous membranes with good flexibility have been successfully fabricated for the first time using an electrospinning technique. The γ-alumina membranes were composed of randomly arranged nanofibers with a high aspect ratio and small diameter (ca. 230 nm). The γ-alumina membranes show high tensile strength (2.98 MPa) and thermal stability (up to 900 °C), which favor their applications in high temperature conditions. Furthermore, the γ-alumina membranes exhibit good filtration performance for 300 nm dioctyl phthalate fine particulate gas filtration. The filtration efficiency is 99.848% and the pressure drop is 239.12 Pa for the membrane calcined at 700 °C with a basis weight of 9.28 g m⁻²; and the filtration efficiency could be over 99.97% when the basis weight is over 11.36 g m⁻², suggesting that the γ-alumina fibrous membrane is a promising candidate for high temperature, fine particulate filtration applications. This work also provides a novel insight into the electrospinning of flexible self-standing inorganic membranes for applications in the separations field.