Electroactive phases of poly(vinylidene fluoride) : determination, processing and applications

Progress in the production and modification of PVDF membranes

Application and modification of poly(vinylidene fluoride) (PVDF) membranes – A review

Mixed ionic-electronic conducting (MIEC) ceramic-based membranes for oxygen separation

A superhydrophobic-superoleophilic PVDF membrane is fabricated via an inert solvent-induced phase inversion for effective separation of both micrometer and nanometer-sized surfactant-free and surfactant-stabilized water-in-oil emulsions solely driven by gravity, with high separation efficiency (oil purity in filtrate after separation > 99.95 wt%) and high flux, which is several times higher than those of commercial filtration membranes and reported materials with similar permeation properties.

Superhydrophobic and superoleophilic PVDF membranes for effective separation of water-in-oil emulsions with high flux.

This article presents a review of the recent development of mixed conducting ceramic materials and membranes, and their potential applications in separations and chemical reactions. A basic knowledge of the materials, including their structure, composition, and properties, is first introduced briefly, followed by a short discussion on the relation between the material structures and properties as well as strategies for new material development and screening. The main part of this review gives an intensive discussion on the progress achieved up to early 2005. Performances of the mixed conducting materials for both oxygen and hydrogen and their function as membranes or membrane reactors are summarized. Some examples in gas/vapor separations and catalytic chemical reactions are presented. Current problems related to the fabrication of the mixed conducting membranes are addressed and future technology challenges are also outlined.

Mixed Conducting Ceramics for Catalytic Membrane Processing

Mixed conducting ceramic hollow-fiber membranes, which possess an asymmetric structure, were prepared by a combined phase inversion and sintering technique where precursors of the hollow fibers were first spun using a polymer solution containing suspended LSCF powders and were then sintered at elevated temperature. By controlling the weight ratio of the LSCF powder to the polymer binder, sintering temperature, and time, the LSCF hollow fibers with gastight properties have been prepared and evaluated using an apparatus developed during the course of this study. Using the gastight LSCF hollow fibers, a membrane module was assembled for air separation. The performances of the module for air separation have been studied under various operating modes and at different temperatures and feed flow rates both experimentally and theoretically. The results reveal that the surface exchange reaction at the downstream side is much more important than that at the upstream side, especially for lower operating temperatures. The porous inner surface of the prepared LSCF hollow-fiber membranes substantially favors the oxygen permeation when air is fed in the shell side of the membrane module. At high operating temperatures, oxygen permeation can be enhanced by the countercurrent flow operation. Vacuum operation favors the oxygen permeation kinetically in the LSCF hollow-fiber membrane modules. © 2005 American Institute of Chemical Engineers AIChE J, 2005

Mixed conducting ceramic hollow‐fiber membranes for air separation

A mixed oxide-electron conducting ceramic, La0.6Sr0.4Co0.2Fe0.8O3-α (LSCF), hollow-fiber membrane was prepared by a combined phase-inversion/sintering technique. The hollow-fiber membrane precursor was first spun from a starting solution containing 66.33 wt % LSCF powder, 6.63 wt % PESf binder, 0.5 wt % PVP additive, and 26.54 wt % NMP and then sintered at elevated temperatures between 1100 and 1280 °C for 4 h to obtain membranes with a gastight property. The hollow-fiber membranes prepared show an asymmetric structure in which a spongelike material is sandwiched by fingerlike structures located at the outer and inner walls of the fibers. Oxygen permeation fluxes through the hollow-fiber membranes were measured under different temperatures and downstream oxygen partial pressures. The results indicated that the oxygen flux obtained from the hollow-fiber membrane is higher than that obtained from conventional LSCF disk-shaped or tubular membranes, most probably because of the reduced thickness and porous in...

Yutie Liu

Papers

Progress in the production and modification of PVDF membranes

Mixed Conducting Ceramics for Catalytic Membrane Processing

Mixed conducting ceramic hollow‐fiber membranes for air separation

Preparation of LSCF Ceramic Hollow-Fiber Membranes for Oxygen Production by a Phase-Inversion/Sintering Technique

Stability of PVDF hollow fibre membranes in sodium hydroxide aqueous solution