Nanocomposite Membranes for PEM-FCs: Effect of LDH Introduction on the Physic-Chemical Performance of Various Polymer Matrices

Abstract

This is a comparative study to clarify the effect of the introduction of layered double hydroxide (LDH) into various polymer matrices. One perfluorosulfonic acid polymer, i.e., Nafion, and two polyaromatic polymers such as sulfonated polyether ether ketone (sPEEK) and sulfonated polysulfone (sPSU), were used for the preparation of nanocomposite membranes at 3 wt.% of LDH loading. Thereafter, the PEMs were characterized by X-ray diffraction (XRD) and dynamic mechanical analysis (DMA) for their microstructural and thermomechanical features, whereas water dynamics and proton conductivity were investigated by nuclear magnetic resonance (PFG and T1) and EIS spectroscopies, respectively. Depending on the hosting matrix, the LDHs can simply provide additional hydrophilic sites or act as physical crosslinkers. In the latter case, an impressive enhancement of both dimensional stability and electrochemical performance was observed. While pristine sPSU exhibited the lowest proton conductivity, the sPSU/LDH nanocomposite was able to compete with Nafion, yielding a conductivity of 122 mS cm−1 at 120 °C and 90% RH with an activation energy of only 8.7 kJ mol−1. The outcome must be ascribed to the mutual and beneficial interaction of the LDH nanoplatelets with the functional groups of sPSU, therefore the choice of the appropriate filler is pivotal for the preparation of highly-performing composites.

Synergistic effect of ultrasound and reinforced electrical environment by bioinspired periosteum for enhanced osteogenesis via immunomodulation of macrophage polarization through Piezo1

“…Particle agglomeration is a major issue, as micro- or nanoparticles can cluster, leading to uneven surface properties and disrupting uniform cell adhesion. This can result in areas with varying mechanical properties, hindering consistent cell growth [ 36 ]. Additionally, pore size and distribution are critical; improper pore sizes can impair nutrient exchange and waste removal, negatively impacting cell health [ 37 ].…”

MWCNTs Decorated with TiO2 as Highly Performing Filler in the Preparation of Nanocomposite Membranes for Scalable Photocatalytic Degradation of Bisphenol A in Water

“…The thermomechanical performance of the membranes was investigated using dynamic mechanical analysis (DMA) on a Metravib DMA/25 analyzer (Metravib Limonest, France) equipped with a shear jaw for clamping the films [ 82 , 83 , 84 ]. Rectangularly shaped samples were directly cut from the membranes and subjected to a dynamic stress of amplitude 10 −4 at 1 Hz.…”