Water-stable crosslinked sulfonated polyimide–silica nanocomposite containing interpenetrating polymer network

Sulfonated hydrocarbon membranes for medium-temperature and low-humidity proton exchange membrane fuel cells (PEMFCs)

“…The use of amphiphilic surfactants in previous research was helpful in demonstrating this strategy [109,183,193,201,216,[225][226][227]. A representative amphiphilic surfactant is a sort of non-ionic triblock copolymer (ABA block, A = poly(ethylene oxide) (PEO) and B = poly(propylene oxide) (PPO), e.g., Pluronics ® ) that has a good balance of hydrophilicity and hydrophobicity so as to distribute the surface-functionalized inorganic additives.…”

“…A representative amphiphilic surfactant is a sort of non-ionic triblock copolymer (ABA block, A = poly(ethylene oxide) (PEO) and B = poly(propylene oxide) (PPO), e.g., Pluronics ® ) that has a good balance of hydrophilicity and hydrophobicity so as to distribute the surface-functionalized inorganic additives. When the surfactant exists in polar solvents (such as water) over its critical micelle concentration, it creates a peculiar micelle structure composed of a hydrophobic PPO core and a hydrophilic PEO shell [216,[226][227][228][229][230]. After the addition of nano-sized inorganic additives (e.g., hydrophilic SiO 2 , Aerosil ® 380 with an average diameter of 7 nm), the surfactant was absorbed on the inorganic surface and the micelle diameter became larger than that of the surfactant as a result of the incorporation of inorganic additives within the surfactant micelle ( Fig.…”

“…For example, the vinyl groups in PEO-PPO-based surfactants can be polymerized using 2,2 ′ -azxobisisobutyronitrile (AIBN) initiator and produce IPN structures (red line). In addition, the hydroxyl groups in the surfactants can produce crosslinked structures through the formation of covalent bonds with other functional groups (e.g., -SO 3 H or -COOH) in the polymer matrices [226,235]. The resulting polymer-SiO 2 nanocomposites have exhibited excellent chemical durability and mechanical strength, as well as improved proton conductivity when compared to a corresponding pure copolymer due to the synergistic effect of well-dispersed SiO 2 and tuned polymer structures.…”

Nafion®–sepiolite composite membranes for improved proton exchange membrane fuel cell performance

“…Different strategies have been followed to overcome the limitation of Nafion®, the perfluorinated ionomer widely chosen as the standard for PEMFC [1,2,3]. Non-fluorinated polymers such as PEEK [4,5,6], PSU [7,8] or PBI [9,10,11,12] and their sulfonated counterparts have been extensively studied as alternatives. Another strategy consists in incorporating inorganic fillers such as metal oxides [13,14,15,16,17,18,19,20,21], acids [22,23,24,25,26], phosphates or phosphonates [27,28,29] into the Nafion® matrix to make the composite or hybrid membrane more mechanically stable, less permeable to reactant and more hygroscopic.…”

Mechanical Properties of Sulfonated Poly (Ether Ether Ketone) Nanocomposite Membranes

“…Organic-inorganic nanocomposites have attracted much interest as membrane for fuel cells, since inorganic nanoparticles in a polymer matrix might improve mechanical strength [15], [16], proton conductivity [16]- [18] fuel barrier properties [16], and membrane durability [16].…”