Synthesis of Porous Inorganic Hollow Fibers without Harmful Solvents

Abstract

A route for the fabrication of porous inorganic hollow fibers with high surface‐area‐to‐volume ratio that avoids harmful solvents is presented. The approach is based on bio‐ionic gelation of an aqueous mixture of inorganic particles and sodium alginate during wet spinning. In a subsequent thermal treatment, the bio‐organic material is removed and the inorganic particles are sintered. The method is applicable to the fabrication of various inorganic fibers, including metals and ceramics. The route completely avoids the use of organic solvents, such as N‐methyl‐2‐pyrrolidone, and additives associated with the currently used fiber fabrication methods. In addition, it inherently avoids the manifestation of so‐called macro voids and allows the facile incorporation of additional metal oxides in the inorganic hollow fibers.

Thin-skinned intrinsically defect-free asymmetric mono-esterified hollow fiber precursors for crosslinkable polyimide gas separation membranes

“…Among different types of membrane materials, polymers are the dominant membrane materials, as essentially all large scale industrial gas separation membranes are polymeric in nature [8][9][10][11]. Asymmetric hollow fiber membranes are attractive for large scale gas separations, due to attractive intrinsic performance, low cost and easy processing [8,12].…”

Synthesis and Characterization of Porous Ceramic Hollow Fibers with Nano-Molecular Size

“…The first step is entails dry-wet spinning of a particle-loaded polymer solution. In the second step, the organic polymer is burned out and the inorganic particles are sintered [14].…”

“…These membranes can be used in several applications such as fabrication of solid oxide fuel cell [3], gas-liquid-solid microreaction technology [4], catalytic reactors [5,6], and porous ceramic microfiltration membranes [7,8]. Several methods have been applied for inorganic hollow fiber membranes synthesis like dry spinning [9,10], wet spinning [2], phase inversion [11][12][13], and bio-ionic gelation [14,15].…”

Micrometer-Scale Kirkendall Effect in the Formation of High-Temperature-Resistant Cr2O3/Al2O3 Solid Solution Hollow Fibers

“…Ceramic hollow fibers, which have many special advantages including high temperature resistance, high surface area, high chemical resistance, and low thermal conductivity, are widely applied to fuel cells, insulating materials, catalyst carriers, gas separation, microchannel reactors, and wastewater treatment. − Increasing attention has been paid to the development of ceramic hollow fibers for their distinct merits. By now, most of the ceramic hollow fibers that are reported are fabricated by the phase inversion/sintering method, the organic template method, and the static filature method. − These kinds of methods have complicated techniques and include such disadvantages as having a high cost and taking a long time, which limit the practical applications of the hollow fibers.…”