(373m) Petrified Hollow Fiber Membranes with Hierarchical Pores

Inorganic membranes often rely on porous oxide hollow fibers as substrates, which are traditionally made by high-temperature methods. For example, the phase inversion-sintering method typically occurs at 1200-1500 °C. These high-temperature fabrication processes are expensive, which limit the large-scale applications of inorganic membranes for chemical separation and filtration. In this poster, we will present the fabrication of novel porous oxide hollow fiber membranes, which we name “petrified hollow fiber membranes”, via petrification of polymer hollow fiber templates at a temperature (600 °C) far below the traditional phase inversion-sintering method. Like petrified wood reproduces the geometry and cell structure of wood, petrified hollow fiber membranes reproduce the hollow fiber geometry and asymmetric macropore structure of polymer hollow fiber templates. These petrified hollow fiber membranes have a unique hierarchical micro-/meso-/macroporous structure giving both high surface area and large pore volume. Their asymmetric macropore structure allows the petrified hollow fiber membranes to efficiently reject macromolecular solutes (e.g., protein) in cross-flow filtration tests. They are also highly gas permeable, and therefore are potentially suitable as substrates of inorganic membranes for gas and vapor separations. The petrified hollow fiber membranes were extensively characterized by scanning and transmission electron microscopy, thermogravimetric analysis, nitrogen and argon physisorption, mercury intrusion porosimetry, infrared spectroscopy, and water vapor adsorption, which allowed us to propose a hypothetical formation mechanism of these novel structures.

References:

¹Liu, L.; Ku, C.-E.; Zhang, C., Petrified Hollow Fiber Membranes with Hierarchical Pores. ACS Materials Letters 2022, 938-943.