In this study, nanocomposite membranes were developed by incorporating sulfonated nanoscale ionic materials (sNIMs) into a sulfonated polysulfone (sPSU) matrix for high-temperature polymer electrolyte membrane fuel cells (PEMFCs), with a focus on direct hydrogen fuel cell (DHFC) applications. The sNIMs, composed of silica nanoparticles functionalized with tethered sulfonic acid groups, were uniformly dispersed within the polymer matrix via solution casting. Structural and electrochemical characterizations demonstrated that the resulting membranes exhibit improved thermal and mechanical stability, enhanced hydration retention, and superior proton conductivity compared to pristine sPSU and recast Nafion. Remarkably, the optimized sNIM-3 formulation achieved 18  mS cm-1 conductivity at 120 °C and 30% RH, outperforming Nafion under identical conditions. Diffusion NMR and impedance spectroscopy revealed that the nanostructured ionic domains introduced by the sNIMs enable efficient proton transport predominantly via a Grotthuss-type hopping mechanism, even at low humidity and elevated temperatures. Fuel cell tests confirmed the exceptional performance of sNIM-3, making these membranes highly attractive fluorine-free candidates for next-generation PEMFCs.

In the present study we developed a thin, mechanically flexible and safe high-energy battery for smart textiles, demonstrating a pathway to eliminate toxic and low-boiling solvents and guiding a development towards solid state batteries.

The realization of polymeric nanocomposites is a promising strategy for large-scale applications of photocatalytic nanomaterials, limiting their dispersion into the environment. In addition, in order to obtain very efficient materials, a valid solution can be the formation of heterojunctions that, reducing the electron-hole recombination phenomena, increases the performances of the photocatalysts. For this work, we have realized promising photocatalytic polymeric nanocomposites through the simple method of sonication and solution casting, using poly (methyl methacrylate) (PMMA) as supporting matrix, ZnO nanoparticles as photoactive material, and MoS2 nanoflakes as co-catalyst for the realization of the heterojunction. Materials with several quantities of MoS2 have been synthetized and characterized by scanning electron microscopy (SEM), contact angle measurements, X-ray diffraction analysis (XRD), UV–Vis spectroscopy, transmission electron microscopy (TEM), and photoluminescence (PL). The photocatalytic performances of the obtained materials were evaluated by the photodegradation under UV light irradiation of two different common pollutants: rhodamine B (RhB) and sodium dodecyl sulfate (SDS). The mechanism of the involved photocatalytic process was studied by the investigation of the main oxidants responsible of the photodegradation, using hole or radical scavengers. The antibacterial properties were investigated using Escherichia coli as a model organism. The eventual toxic effects of the prepared materials were studied on Artemia salina.

Rising plastic waste from products such as contact lenses underscores the need for innovative recycling solutions. This study presents a sustainable approach to produce reusable photocatalytic hybrid nanocomposites for water treatment through the use of waste contact lenses. TiO2 nanoparticles were uniformly integrated into postused contact lenses via a controlled spray deposition technique, resulting in nanocomposites with different spray times (10, 15, or 20 min). The innovative polymeric hybrids were comprehensively characterized from a morphological, structural, and chemical standpoint using techniques such as scanning and transmission electron microscopy, thermogravimetric analysis, X-ray diffraction analysis, Raman spectroscopy, Z-potential analysis, UV-vis spectroscopy, and Fourier transform infrared spectroscopy. The UV-photocatalytic performance of the resulting systems was successfully tested on two common pollutants: methylene blue (a cationic dye) and sodium dodecyl sulfate (an anionic surfactant). The highest efficiency was obtained through the 20 min spray-coated lenses, able to degrade similar to 100% of MB and similar to 60% of SDS within 3 h of UV-light irradiation. The difference in the photocatalytic efficiency was attributed to the electrostatic interaction between the individual pollutant and the material's surface. In addition, the antibacterial activity was assessed on Escherichia coli, a well-known indicator of water fecal contamination. This research paves the way for recycling plastic waste through an affordable and cost-effective production method that aligns with the circular economy principles.

Next-generation electrolytes for Lithium Ion Batteries (LIBs) must provide increased durability, reliability, safety, and scalability to meet the even more stringent technical requirements of crucial industries such as e-mobility. A promising strategy to merge these technical needs is the development of easy-to-prepare gel polymer electrolytes (GPEs) able to ensure satisfactory conductivity, high stability, and reduced flammability. In this study, we propose the preparation of novel nanocomposite GPEs through one-pot in-situ photo-polymerization (UVcuring), which turns out to be of great interest due to its low-cost, solvent-free and energy-saving characteristics. Poly (ethylene glycol) dimethacrylate (PEG-DMA) was used as hosting polymer matrix, while 1 M Lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) in ethylene carbonate/dimethyl carbonate (EC/DMC) was used as electrolyte solution. Organo-modified montmorillonite (fMt, intercalated with CTAB) was synthesized and tested as a nanofiller. Both materials and GPEs were characterized by a combination of experimental techniques including FTIR, XRD, SEM, and DMA. Noteworthy, a thorough and systematic study of the lithium-ion transport properties in the prepared GPEs was carried out using pulsed-field gradient nuclear magnetic resonance (PFGNMR) and electrochemical impedance spectroscopy (EIS). This preliminary study demonstrated the gP-fMt combines ease of preparation and excellent safety (i.e., thermomechanical stability up to 250 degrees C and nonflammability) with satisfactory lithium transport properties.

Abstract A successful strategy for improving the safety issues of new‐generation lithium‐ion batteries is to replace liquid electrolytes with solid or quasi‐solid membranes, a procedure that ensures adequate ionic conductions and are mechanical strengths.

The synergistic combination of Nafion and sulfonated graphene oxide (GOsulf) in nanocomposite membranes emerged as a promising strategy for advancing proton exchange membrane fuel cell (PEMFC) technology. In the pursuit of elucidating the effect of GOsulf introduction on transport properties and electrochemical performance of Nafion, this work provides a systematic study combining swelling tests, water release tests, 1H NMR characterization, and Electrochemical Impedance Spectroscopy (EIS) investigation. The incorporation of organomodified GO nanolayers alters the distribution of water molecules within the hydrophilic domains of Nafion and produces a considerable increase in the “bound-water” fraction. This increases its water retention capability while ensuring very high diffusivity even under high temperatures, i.e., 1.5 × 10−5 cm2 s−1 at 130 °C. These peculiar features enable Naf-GOsulf to successfully operate under a dehydrating environment, yielding a proton conductivity of 44.9 mS cm−1 at 30% RH.

Lithium-sulfur batteries are considered a strong contender for next-generation high-energy battery systems given their high gravimetric energy density. However, this battery chemistry is still facing challenges such as the polysulfide shuttle effect caused by the high solubility of long-chain lithium polysulfides (Li2Sn) resulting in active material loss and compromised cycle life. Solid-state polymer electrolytes (SPEs) represent a promising pathway to address this issue by preventing the formation and transport of these undesirable polysulfide intermediates.1,2 Moreover, the application of flexible polymer electrolytes promotes safe high energy batteries for smart textiles. In this study, single lithium-ion conducting solid polymer electrolytes (SLIC-SPEs) based on lithiated Nafion membrane have been investigated, utilizing the chemical and thermal stability of this kind of ionomers. Among others, a mixture of ethylene carbonate (EC) and propylene carbonate (PC) was tested as organic aprotic swelling solvent offering advantageous characteristics such as great chemical stability and high ion mobility while avoiding phase separation issues and undesired leaching. Sulfur-infiltrated ultramicroporous carbon composite cathodes were utilized in combination with the investigated SLIC-SPEs, facilitating a quasi-solid-state lithium-sulfur full cell with carbonate-solvent compatibility and high active material utilization.3 Electrochemical performance of the full cell was investigated elaborately and compared with a reference system using solely the liquid EC:PC solvent. While rapid capacity fading can be observed for the liquid electrolyte cell, an enduring high capacity is found in the lithiated-Nafion system. For better understanding of these effects, cycling analysis was accompanied by implementing impedance spectroscopy upon galvanostatic cycling. The electrochemical characterization indicates the formation of a stable film and high degree of reversibility during cycling of the lithiated-Nafion cell whereas an increased film resistance due to sulfur cross-over and electrolyte decomposition was observed within the liquid electrolyte system. (1) Z. Li, W. Lu, N. Zhang, Q. Pan, Y. Chen, G. Xu, D. Zeng, Y. Zhang, W. Cai, M. Yang, J. Mater. Chem. A 2018, 6 (29), 14330-14338. (2) X. Hao, H. Wenren, X. Wang, X. Xia, J. Tu, J. Colloid Interface sci. 2020, 558, 145-154, (3) M. Nojabaee, B. Sievert, M. Schwan, J. Schettler, F. Warth, N. Wagner, B. Milow, K. A. Friedrich, J. Mater. Chem. A 2021, 9 (10), 6508-6519,

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.

We report on an extensive study on nanocomposite Anion Exchange Membranes (AEMs) based on tetramethylammonium Polysulfone ionomer and Layered Double Hydroxide (LDH) as nanofiller. The AEMs were investigated in both OH- and HCO3- forms, comparing swelling capacity and transport properties. Ionic conductivity measurements were performed both by Electrochemical Impedance Spectroscopy and Ziv and Dekel's method, while the water and ions mobility by H-1 Pulse Field Gradient (PFG) NMR spectroscopy. One of the most serious problems to be addressed in AEMs fuel cell technology is that of the significant loss of performance when CO2 is present in the reaction oxidant gas (e.g., air) due to the phenomenon of carbonation. In this work, the carbonation kinetics of AEMs and the effect of LDH filler were addressed through C-13 NMR spectroscopy (including diffusometry and relaxometry measurements). The presence of LDH platelets in the AEM significantly reduces the conversion rate of hydroxide groups. The interaction between the polymer chains and the anionic clay lamellae creates a suitable network that benefits the membrane's ionic conductivity, its mechanical properties (DMA tests), and finally reduces the rate of alkaline degradation. (C) 2021 Elsevier Ltd. All rights reserved.

Electrochemical energy conversion and storage (EECS) technologies such as fuel cells and electrolyzers are expected to play a pivotal role owing to their compatibility with the environment and high energy conversion efficiency. Anion-exchange membranes (AEMs) have received increased interest in recent years as the electrolyte separator in different EECS devices.[1] They have numerous advantages respect to the proton-exchange membranes, such as operation at high pH conditions, significantly lower cost (based on low-cost raw materials), less corrosive environment, and significantly lower fuel crossover (one order of magnitude lower than the acidic counterparts). AEM fuel cells and electrolyzers devices can reach the performance level required by applications with electrocatalysts that do not require a high loading of platinum-group metals (PGMs) due to the alkaline environment at the electrodes. However, the AEM based EECS development and implementation is significantly hindered by the anion exchange membrane (AEM) stability during cell operation, their low OH- conductivity and the low kinetics of the electrocatalysts. In fact, the electrolytic anion-exchange membrane (AEM) is a crucial component which should allow good charge and water transport, i.e. high ionic conductivity, but should also guarantee good chemical, thermal and mechanical stability and high durability. [2] We report on an extensive study on nanocomposite AEMs based on tetramethylammonium Polysulfone ionomer (PSU) and Layered Double Hydroxide (LDH) as nanofiller. [3] PSU is a thermoplastic polymer with high thermal stability, good chemical resistance and mechanical properties. However, since it has two activated positions per repetition unit for electrophilic aromatic substitution, it can undergo high degrees of functionalisation, which reduce the mechanical properties. We developed a two steps procedure, with allow a functionalization degree of about 80%, preserving its stability. Concerning the LDHs, these mineral anionic clays are excellent inorganic anionic conductors with elevated ion exchange capacity (IEC). They consist of the positively charged metal hydroxide layers with anions located in the interlayer space. This allows strong hydration of the material together with a large number of hydroxyls on the host layers forming a dense network of hydrogen bonds along the two-dimensional surface, therefore facilitating OH- ion conduction by diffusion mechanism. PSU/LDH AEMs were investigated in both OH- and forms, comparing swelling capacity, ionic conductivity and water diffusion. The latter was studied by NMR spectroscopy, measuring the self-diffusion coefficient by the Pulse Field Gradient (PFG) NMR techniques. The nanocomposite membranes are able to maintain good hydration at high temperatures, and to create an adequate nanostructure with the polymer chains, which favour the Grotthuss diffusion mechanism for the OH- ions. Such feature is reflected in the ionic conductivity and in the alkali stability, where they demonstrated the highest conductivity and a reduced membrane degradation rate. In addition, the 13C-NMR technique was used to investigate carbonation processes in the presence of CO2, showing that the presence of the LDH platelets into the AEM remarkably reduces the conversion rate of hydroxyl groups, as much as slow down the diffusion of carbonate ions. Finally, electrolysis cell tests were conducted on MEAs based on these hybrid membranes, and preliminary results showed very promising performance. Acknowledgments This work has been supported by the Italian Ministry for University and Research (MUR) for funding through the FISR 2019 project AMPERE (FISR2019_01294). References Vincent, I. and Bessarabov, D. (2018) Renewable and Sustainable Energy Reviews 81, 1690–704 G. Arges, L. Zhang, ACS Appl. Energy Mater. 1 (2018) 2991–3012, Simari, C.,...and Nicotera, I. (2022) Electrochimica Acta, 403, p. 139713.

The ease and low environmental impact of its preparation, the reduced fuel crossover, and the low cost, make sulfonated polyether ether ketone (sPEEK) a potential candidate to replace the Nafion ionomer in proton exchange membrane fuel cells (PEMFCs). In this study, sPEEK was used as a polymer matrix for the preparation of nanocomposite electrolyte membranes by dispersing an organo-silica layered material properly functionalized by anchoring high phosphonated (PO3H) ionic groups (nominated PSLM). sPEEK-PSLM membranes were prepared by the solution intercalation method and the proton transport properties were investigated by NMR (diffusometry-PFG and relaxometry-T1) and EIS spectroscopies, whereas the mechanical properties of the membranes were studied by dynamic mechanical analysis (DMA). The presence of the organosilica nanoplatelets remarkably improved the mechanical strength, the water retention capacity at high temperatures, and the proton transport, in particular under harsh operative conditions (above 100 °C and 20–30% RH), usually required in PEMFCs applications.

A novel good performing and selective polymeric sorbent has been synthesized by chemical modification of ecofriendly and inexpensive polysulfone through introduction of quaternary ammonium pendant groups (qPSU). The self-standing film conjugated outstanding thermo-mechanical resistance with high selectivity of adsorption for CO2 over methane, fast capture kinetics and very good stability over multiple adsorption-desorption cycles. Worth notes, the qPSU sorbent exhibited absorption capacity up to 2.21 mmol g-1 under simulated flue gas conditions (humid 6 % CO2, 20 % relative humidity and ambient pressure) and one of the highest amine efficiency reported to date for low-temperature and low-pressure CO2 sorbents. The maximum adsorption capacity can be completely restored under mild conditions (50 degrees C in pure N2 for 20 min), with only 60.3 kJ mol-1 consumed during sorbent regeneration. 13C NMR characterization revealed carbon dioxide is chemisorbed via formation of bicarbonate ions. The approach may be further extended to a wide range of polymeric systems, and thus might open up new avenues in the development of advanced carbon dioxide sorbents.

Currently, rechargeable batteries with the lithium–sulfur (Li–S) chemistry has attracted great interest as one of the most promising candidates for next generation electrochemical energy storage systems. Research into these high energy density devices is critical to the development of thinner, lighter, and lower cost battery systems. One of the biggest obstacles for practical applications of Li-S batteries is caused by the soluble nature of the highly ordered lithium polysulfides (Li2Sn) in the organic electrolytes and induce a so-called “shuttle effect”. A solid-state electrolyte (SPEs) could be a valid alternative in terms of reducing the polysulfides dissolution and shuttle, as well as to protect the lithium metal anode and to minimize dendrite formation, which is beneficial for improving the safety and cycle life of Li−S batteries. SPEs are typically dual-ion conductor systems both cations and anions are mobile and cause a concentration polarization leading to poor performances of batteries. Recently, single lithium-ion conducting solid polymer electrolytes (SLIC-SPEs) have been proposed for polymer electrolytes, where anions are covalently bonded to the polymer, inorganic backbone, or immobilized by anion acceptors and only the Li+ cation will contribute to a permanent flow of charge. They have advantages over conventional dual-ion conducting SPEs such as unity transference number, absence of harmful effect of anion polarization, extremely low rate of Li dendrite growth and immobilization of the lithium polysulfides in the lithium-sulfur (Li-S) batteries. Polymer electrolytes based on ionomers (e.g., Nafion) with easily ionizable groups (e.g., sulfonic groups covalently bonded to the polymer side-chains, −CF2SO3 −) are promising thanks to the high concentration of weakly coordinating anions (counterions). In this work, lithiated Nafion and Nafion-nanocomposites membranes based on Nanoscale Ionic Materials (NIMs) were synthesized, and their ionic conductivity and lithium transference number were investigated in common nonaqueous organic solvents (EC/PC and Glymes). A thorough and systematic study of the lithium-ion transport was conducted by p 1H and 7Li pulsed field gradient (PFG) NMR spectroscopy and electrochemical impedance spectroscopy (EIS), while the mechanical properties of the film electrolytes have been tested by dynamic mechanical analysis (DMA) in a wide temperature range. The electrochemical studies have been conducted both in Li/Li symmetric cell and in secondary Li-S cells. The preliminary results are very interesting, showing ionic conductivities of the order of 5 × 10-4 S/ cm at 25°C satisfactory properties in terms of stability window and stability of the lithium stripping. The lithium transport number is very close to unity thus confirming the complete immobilization of the negative charge carriers.

A trimethylammonium-functionalized polyepichlorohydrin membrane (TPp) was synthesized using inexpensive, eco-friendly raw materials and easy synthetic steps and evaluated as CO2 sorbent. The polymeric membrane exhibited satisfactory sorbent performance in terms of stability, rapid adsorption, high selectivity and working capacity. The peak capture capability of 1.34 mmol g-1 was achieved at 25 degrees C under simulated flue gas condition (humidified 10% CO2, 20% RH). The quaternary ammonium groups enable superior amine efficiency (0.95 mmol CO2/mmol N at 25 degrees C), well exceeding the highest value reported to date for low-temperature CO2 sorbents under simulated flue gas conditions, and reversible trap-release of CO2. De facto, the TPp sorbent can be completely regenerated under mild conditions (50 degrees C in pure N2 for 20 min), with only 64.8 kJ mol-1 consumed during sorbent regeneration. The low cost, versatility and ease of preparation make the TPp membrane a promising sorbent for scalable and cost-effective CO2 capture.

Gel polymer electrolytes (GPEs), based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), 1 M LiPF6 in ethylene carbonate/dimethyl carbonate (EC/DMC), so called LP30, and 1-butyl-1-methylpyrrolidinium hexafluorophosphate ([Py-14]PF6), have been developed to improve inherent safety of the electrolyte for high voltage lithium batteries. Dry PVdF-HFP membranes, prepared with EC/DMC, were soaked in LP30 in addition to its mixtures with 30 wt% and 50 wt% [Py-14]PF6 to obtain GPEs. Nonflammable character and mechanical stability enhanced via physical crosslinks of the GPEs are demonstrated with flammability tests and rheological measurements, respectively. Lithium ion conduction property in the GPEs is evaluated by means of both electrochemical impedance spectroscopy and NMR spectroscopy (Pulsed Field Gradient-PFG and relaxation time). Galvanostatic charge and discharge cycles of lithium metal batteries having LiNi0.6Mn1.6O4 as a high voltage cathode demonstrate improved electrochemical performance with coulombic efficiency above 99% and high specific capacity above 110 mAh g(-1) at C/5 throughout 150 cycles, when the GPE containing LP30 with 30 wt% [Py-14]PF6 is used. The capacity retention is sufficiently high compared to the GPE without [Py-14]PF6, confirming that the IL is a highly promising additive for improving battery life. (C) 2021 Elsevier Ltd. All rights reserved.

Conventional Nafion membranes demonstrate a strong affinity for methanol, resulting in a high fuel crossover, poor mechanical stability, and thus poor performance in direct methanol fuel cells (DMFCs). This study involves the synthesis and physiochemical characterization of an alternative polymer electrolyte membrane for DMFCs based on sulfonated poly(ether ether ketone) and a layered double hydroxide (LDH) material. Nanocomposite membranes (sPL), with filler loading ranging between 1 wt% and 5 wt%, were prepared by simple solution intercalation and characterized by XRD, DMA, swelling tests, and EIS. For the first time, water and methanol mobility inside the hydrophilic channels of sPEEK-LDH membranes were characterized by NMR techniques. The introduction of LDH nanoplatelets improved the dimensional stability while having a detrimental effect on methanol mobility, with its self-diffusion coefficient almost two orders of magnitude lower than that of water. It is worth noting that anionic lamellae are directly involved in the proton transport mechanism, thus enabling the formation of highly interconnected paths for proton conduction. In this regard, sPL3 yielded a proton conductivity of 110 mS cm−1 at 120 °C and 90% RH, almost attaining the performance of the Nafion benchmark. The nanocomposite membrane also showed an excellent oxidative stability (over more than 24 h) during Fenton’s test at 80 °C. These preliminary results demonstrate that an sPL3 nanocomposite can be potentially and successfully applied in DMFCs.

Novel nanocomposite proton exchange membranes based on an organo-sulfonated derivative of the graphene oxide (SGO) incorporated in sulfonated Polysulfone (sPSU) were successfully fabricated via scalable, cost-effective and eco-friendly solution casting method for high-performing PEM fuel cells. The microstructure, physicochemical features and the electrochemical performance were widely investigated by a combination of various techniques including PFG-NMR spectroscopy, DMA and H-2-O-2 single-cell tests. Homogeneous and completely exfoliated sPSU-SGO nanocomposite membranes displayed outstanding thermal and mechanical stabilities as a result of strong interfacial interactions between the graphene nanoplatelets and the sulfonic acid groups on the polymer chains. This, together with the large number of acidic functionalities present in the SGO nanoadditive, greatly improved the water retention capacity of the membrane and increased proton transport through an effective Grotthuss-type mechanism, especially under very low humidification conditions. For instance, at 80 degrees C and 20% RH, the proton conductivity of the sPSU-SGO membrane was 9.4 mS cm(-1) and H-2/O-2 cell test yielded a maximum power density of 182.6 mW cm(-2) @ 110 degrees C and 25%RH. These values exceeded that of Nafion 212, used here as a benchmark, demonstrating that this hybrid electrolyte is an interesting and viable candidate for the next generation of high-temperature PEMFCs. (C) 2021 Elsevier Ltd. All rights reserved.