Highly permeable and mechanically robust silicon carbide hollow fiber membranes

Abstract

a b s t r a c tSilicon carbide (SiC) membranes have shown large potential for applications in water treatment. Being able to make these membranes in a hollow fiber geometry allows for higher surface-to-volume ratios. In this study, we present a thermal treatment procedure that is tuned to produce porous silicon carbide hollow fiber membranes with sufficient mechanical strength. Thermal treatments up to 1500 1C in either nitrogen or argon resulted in relatively strong fibers, that were still contaminated with residual carbon from the polymer binder. After treatment at a higher temperature of 1790 1C, the mechanical strength had decreased as a result of carbon removal, but after treatments at even higher temperature of 2075 1C the SiC-particles sinter together, resulting in fibers with mechanical strengths of 30-40 MPa and exceptionally high water permeabilities of 50,000 L m À 2 h À 1 bar À 1 . Combined with the unique chemical and thermal resistance of silicon carbide, these properties make the fibers suitable microfiltration membranes or as a membrane support for application under demanding conditions.

Light and Strong SiC Networks

“…Silicon carbide is a very appealing material for the fabrication of light structures and microlattices. It combines excellent thermal stability and shock resistance, low thermal expansion, superb mechanical strength, and high chemical stability . As a consequence, light and porous SiC structures are of interest for a number of advanced technological applications.…”

Synthesis, physical and magnetic properties of BaFe12O19/P(VDF-TrFE) multifunctional composites

“…Additionally, the range of geometries available for these polymer-based multiferroic composites is extended by fabricating 0-1 nanofibers of BaFe 12 O 19 particles in a PVDF matrix. Materials in the form of porous membranes, made by weaving the fibers, have attracted interest for various applications, including filtration [11], biomedical applications, sensors, lithium ion membrane separators and chemical protection, among others [12], and may permit the development of new magnetoelectric devices [13]. PVDF was used in the composite fibers because the electrospinning process, used in the fabrication of fibers, promotes the nucleation of the piezoelectric b-phase [14].…”

The mechanical strength of a ceramic porous hollow fiber

“…In current literature the 3-point and 4-point bending test are used interchangeably, both with various inner and outer span sizes [8,[46][47][48]. Recently the use of diametric compression tests is reported to assess the strength of inorganic hollow fibers [13,49].…”

“…In addition to this, many methods are used to assess the mechanical robustness of inorganic fibers; most commonly their flexural or bending strength is determined via a 3-point [2][3][4][5][6] or 4-point bending test [7][8][9][10]. Alternatives include burst pressure measurements [11,12] or diametrical compression tests [13,14].…”