PEBAX 3533/PAA/CNC Composite Fiber Membranes as the Humidifier Membrane for Proton Exchange Membrane Fuel Cells

Abstract

A new type of humidification membrane for proton exchange membrane fuel cells composed of polyether-block polyamide (PEBAX) 3533, polyacrylic acid (PAA), and cellulose nanocrystals (CNCs) was fabricated using the electrospinning method. CNCs were used to improve the hydrophilicity of the membrane, and PAA was used to improve the spinnability of the material. Using a scanning electron microscope, the morphology of PEBAX/PAA/CNC composite fiber membranes (CFMs) and electrospun fibers was investigated. Through X-ray diffraction analysis and the tests of water vapor permeability, air permeability, and water contact angles, the effects of CNCs on membrane properties were investigated. The results showed that the addition of CNCs improved the hydrophilicity and crystallinity of the CFM; while the air barrier properties of the CFM improved, the water vapor permeability coefficient of the membranes decreased. When the content of CNCs was 4.8 wt %, the vapor/air selectivity reached the highest value of (2.20 ± 0.05) × 10 4 , which was 14% more than that of the fiber membrane without CNCs.

Polyether Block Amide as Host Matrix for Nanocomposite Membranes Applied to Different Sensitive Fields

“…Table 8 summarizes the properties of these nanocomposites, comparing them to the benchmark Nafion membranes as dehumidifiers for PEMFCs. The porous fibre membranes display a better air barrier behaviour than the Nafion membranes, while their vapour/air selectivity was similar to Nafion 212 and better than Nafion 211 [48]. However, the MMT fillers were more effective in improving the barrier properties to air due to their lamellar configuration that increases the pathway tortuosity [46].…”

“…The porous structure of UF membranes facilitated water permeation, resulting in better performance than dense Nafion-based membranes for PEMFCs [90]. Porous humidification membranes were fabricated by combining Pebax ® 3533, polyacrylic acid (PAA) and cellulose nanocrystals (CNCs) in an electrospinning device [48]. CNCs were used to improve the hydrophilicity of the membrane, while PAA was added to increase the spinnability of the material.…”

Holmium-Containing Metal-Organic Frameworks as Modifiers for PEBA-Based Membranes

“…These polymers have a number of properties, such as flexibility, chemical resistance and strength, that make them promising for use in membrane technologies [ 54 , 55 , 56 ]. Recently, a number of studies have been carried out on the use of mixed matrix membranes based on PEBA not only for the separation of gases [ 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 ] but also for the extraction of various biofuel components [ 67 , 68 ], alcohols [ 69 , 70 ], desulphurization [ 71 ], alcohol dehydration [ 72 ], esterification [ 73 ] and pervaporation [ 74 , 75 ]. The high degree of combinatoriality in the preparation of block copolymers makes it possible to obtain a large number of commercially available polymers with different compositions and properties [ 76 ].…”