The effectiveness of copper oxide-modified electrochemical sensors using different polymers is being studied. The commercial powder was sonicated in an isopropyl alcohol solution and distilled water with 5 wt% polymers (chitosan, Nafion, PVP, HPC, α-terpineol). It was observed that the chitosan and Nafion caused degradation of CuO, but Nafion formed a stable mixture when diluted. The modified electrodes were drop-casted and analyzed using cyclic voltammetry in 0.1 M KCl + 3 mM [Fe(CN)6]3-/4- solution to determine the electrochemically active surface area (EASA). The results showed that α-terpineol formed agglomerates, while HPC created uneven distributions, resulting in poor stability. On the other hand, Nafion and PVP formed homogeneous layers, with PVP showing the highest EASA of 0.317 cm2. In phosphate-buffered saline (PBS), HPC and PVP demonstrated stable signals. Nafion remained the most stable in various electrolytes, making it suitable for sensing applications. Testing in 0.1 M NaOH revealed HPC instability, partial dissolution of PVP, and Cu ion reduction. The type of polymer used significantly impacts the performance of CuO sensors. Nafion and PVP show the most promise due to their stability and effective dispersion of CuO. Further optimization of polymer-CuO combinations is necessary for enhanced sensor functionality.

Xerosydryle belongs to a new category of materials resulting from the interaction of water with various hydrophilic polymers. These materials can exhibit different properties depending on the kind of polymer-water interaction. Previous research confirmed the existence of a solid manifestation of water at room temperature. The thermal properties of dissolved xerosydryle in water are similar to those of biological macromolecules during denaturation but with greater stability. This study investigated the biological effect of xerosydryle on a living system for the first time, using a seed germination model. The interaction was evaluated using physiological assays such as chlorophyll shifts, potassium (re)uptake during the onset of germination and a transcriptome approach. Seeds were treated with samples of xerosydryle and distilled water. Transcriptome analysis of germinating seeds highlighted differences (up- and down-regulated genes) between seeds treated with xerosydryle and those treated with distilled water. Overall, the experiments performed indicate that xerosydryle, even at low concentrations, interferes with seedling growth in a manner similar to an osmotic modulator. This work paves the way for a more comprehensive exploration of the active biological role of xerosydryle and similar compounds on living matter and opens up speculation on the interactions at the boundaries between physics, chemistry, and biology.

Nafion membranes are widely used as proton exchange membranes, but their proton conductivity deteriorates in high-temperature environments due to the loss of water molecules. To address this challenge, we propose the utilization of porous aromatic frameworks (PAFs) as a potential solution. PAFs exhibit remarkable characteristics, such as a high specific surface area and porosity, and their porous channels can be post-synthesized. Here, a novel approach was employed to synthesize a PAF material, designated as PAF-45D, which exhibits a specific surface area of 1571.9 m2·g-1 and possesses the added benefits of facile synthesis and a low cost. Subsequently, sulfonation treatment was applied to PAF-45D in order to introduce sulfonic acid groups into its pores, resulting in the formation of PAF-45DS. The successful incorporation of sulfonic groups was confirmed through TG, IR, and EDS analyses. Furthermore, a novel Nafion composite membrane was prepared by incorporating PAF-45DS. The Nyquist plot of the composite membranes demonstrates that the sulfonated PAF-45DS material can enhance the proton conductivity of Nafion membranes at high temperatures. Specifically, under identical film formation conditions, doping with a 4% mass fraction of PAF-45DS, the conductivity of the Nafion composite membrane increased remarkably from 2.25 × 10-3 S·cm-1 to 5.67 × 10-3 S·cm-1, nearly 2.5 times higher. Such promising and cost-effective materials could be envisioned for application in the field of Nafion composite membranes.

The nanostructure of Nafion and poly(vinylidene fluoride) (PVDF) blend membranes is successfully aligned through a mechanical uniaxial stretching method. The phase-separated morphology of Nafion molecules distinctly forms hydrophilic proton channels with increased connectivity, resulting in enhanced proton conductivity. Additionally, the crystalline phase of PVDF molecules undergoes a successful transformation from the α- to β-phase during membrane stretching, demonstrating an alignment of fluorine and hydrogen atoms with a TTTT(trans) structure. The aligned nanostructure of the blend film, combined with the dipole polarization of the β-phase PVDF, synergistically enhances the proton conduction through the membrane for operating proton-exchange membrane fuel cells (PEMFCs). The controlled structures of the blend membranes are thoroughly investigated using atomic force microscopy and small-angle X-ray scattering. Furthermore, the improved in-plane proton conductivity facilitates increased proton conduction at the interface between the membrane and catalyst layer in the membrane-electrode assembly, ultimately enhancing the power generation of PEMFCs.

Here, the optical properties of the Nafion polymer membrane containing colloidal CdSe/CdS/ZnS nanocrystals embedded by diffusion have been studied. The CdSe/CdS/ZnS nanocrystals have a core/shell/shell appearance. All experiments were carried out at room temperature (22 ± 2) °C. A toluene solution was used to provide mobility to the active sulfone groups of the Nafion membrane and to embed the nanocrystals inside the membrane. The diffusion process of colloidal CdSe/CdS/ZnS nanocrystals into Nafion proton exchange membrane has resulted in a new molecular complex \"Nafion-colloidal CdSe/CdS/ZnS nanocrystals\". The kinetics of the nanocrystals embedding into the membrane matrix was investigated using luminescence analysis and absorption spectroscopy techniques. The embedding rate of CdSe/CdS/ZnS nanocrystals into the Nafion polymer membrane was approximately 4·10-3 min-1. The presence of new luminescence centers in the membrane was proved independently by laser emission spectroscopy. The luminescence spectrum of the resulting molecular complex contains intensity maxima at wavelengths of 538, 588, 643 and 700 nm. The additional luminescence maximum observed at the 643 nm wavelength was not recorded in the original membrane, solvent or in the spectrum of the semiconductor nanoparticles. The luminescence maximum of the colloidal CdSe/CdS/ZnS nanocrystals was registered at a wavelength of 634 nm. The intensity of the luminescence spectrum of the membrane with embedded nanocrystals was found to be higher than the intensity of the secondary emission peak of the initial nanocrystals, which is important for the practical use of the \"Nafion-colloidal nanocrystals\" complex in optical systems. The lines contained in the luminescence spectrum of the membrane, which has been in solution with colloidal nanocrystals for a long time, registered upon its drying, show the kinetics of the formation of the molecular complex \"Nafion membrane-nanocrystals\". Colloidal nanocrystals located in the Nafion matrix represent an analog of a luminescent transducer.

Polytetrafluoroethylene (PTFE) and, by extension, fluoropolymers are ubiquitous in science, life, and the environment as perfluoroalkyl pollutants (PFAS). In all cases, it is difficult to transform these materials due to their chemical inertness. Herein, we report a direct amination process of PTFE and some fluoropolymers such as polyvinylidene fluoride (PVDF) and Nafion by lithium alkylamide salts. Synthesizing these reactants extemporaneously between lithium metal and an aliphatic primary di- or triamine that also serves as a solvent leads to the rapid nucleophilic substitution of fluoride by an alkylamide moiety when in contact with the fluoropolymer. Moreover, lithium alkylamides dissolved in suitable solvents other than amines can react with fluoropolymers. This highly efficient one-pot process opens the way for further surface or bulk modification if needed, providing an easy, inexpensive, and fast experiment protocol on large scales.

This paper introduces a novel solid-state electrolyte-based enzymatic sensor designed for the detection of acetone, along with an examination of its performance under various surface modifications aimed at optimizing its sensing capabilities. To measure acetone concentrations in both liquid and vapor states, cyclic voltammetry and amperometry techniques were employed, utilizing disposable screen-printed electrodes consisting of a platinum working electrode, a platinum counter electrode, and a silver reference electrode. Four different surface modifications, involving different combinations of Nafion (N) and enzyme (E) layers (N + E; N + E + N; N + N + E; N + N + E + N), were tested to identify the most effective configuration for a sensor that can be used for breath acetone detection. The sensor\'s essential characteristics, including linearity, sensitivity, reproducibility, and limit of detection, were thoroughly evaluated through a range of experiments spanning concentrations from 1 µM to 25 mM. Changes in acetone concentration were monitored by comparing currents readings at different acetone concentrations. The sensor exhibited high sensitivity, and a linear response to acetone concentration in both liquid and gas phases within the specified concentration range, with correlation coefficients ranging from 0.92 to 0.98. Furthermore, the sensor achieved a rapid response time of 30-50 s and an impressive detection limit as low as 0.03 µM. The results indicated that the sensor exhibited the best linearity, sensitivity, and limit of detection when four layers were employed (N + N + E + N).

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), a conductive polymer, has gained popularity as the channel layer in organic electrochemical transistors (OECTs) due to its high conductivity and straightforward processing. However, difficulties arise in controlling its conductivity through gate voltage, presenting a challenge. To address this issue, aromatic amidine base, diazabicyclo[4.3.0]non-5-ene (DBN), is used to stabilize the doping state of the PEDOT chain through a reliable chemical de-doping process. Furthermore, the addition of the proton-penetrable material Nafion to the PEDOT:PSS channel layer induces phase separation between the substances. By utilizing a solution containing both PEDOT:PSS and Nafion as the channel layer of OECTs, the efficiency of ion movement into the channel from the electrolyte is enhanced, resulting in improved OECT performance. The inclusion of Nafion in the OECTs\' channel layer modifies ion movement dynamics, allowing for the adjustment of synaptic properties such as pulse-paired facilitation, memory level, short-term plasticity, and long-term plasticity. This research aims to introduce new possibilities in the field of neuromorphic computing and contribute to biomimetic technology through the enhancement of electronic component performance.

Ensuring the stable operation of proton exchange membrane fuel cells is conducive to their real-world application. A promising direction for stabilizing electrodes is the stabilization of the ionomer via the formation of surface compounds with graphene. A comprehensive study of the (electrochemical, chemical, and thermal) stability of composites for fuel cell electrodes containing a modifying additive of few-layer graphene was carried out. Electrochemical stability was studied by cycling the potential on a disk electrode for 5000 cycles. Chemical stability was assessed via the resistance of the composites to H2O2 treatment using ion-selective potentiometry. Thermal stability was studied using differential thermal analysis. Composites were characterized by UV-Vis spectroscopy, Raman spectroscopy, EDX, and SEM. It was shown that graphene inhibits Nafion degradation when exposed to heat. Contrariwise, Nafion is corrosive to graphene. During electrochemical and chemical exposure, the determining change for carbon-rich composites is the carbon loss (oxidation) of the carbon material. In the case of carbon-poor composites, the removal of fluorine and sulfur from the Nafion polymer with their partial replacement by oxygen prevails. In all cases, the F/S ratio is stable. The dispersity of Nafion in a sample affects its chemical stability more than the G/Nafion ratio does.

Rechargeable sodium-oxygen (Na-O2) battery is deemed as a promising high-energy storage device due to the abundant sodium resources and high theoretical energy density (1,108 Wh kg-1). A series of quasisolid electrolytes are constantly being designed to restrain the dendrites growth, the volatile and leaking risks of liquid electrolytes due to the open system of Na-O2 batteries. However, the ticklish problem about low operating current density for quasisolid electrolytes still hasn\'t been conquered. Herein, we report a rechargeable Na-O2 battery with polyvinylidene fluoride-hexafluoropropylene recombination Nafion (PVDF-HFP@Nafion) based quasisolid polymer electrolyte (QPE) and MXene-based Na anode with gradient sodiophilic structure (M-GSS/Na). QPE displays good flame resistance, locking liquid and hydrophobic properties. The introduction of Nafion can lead to a high Na+ migration number (tNa+ = 0.68) by blocking the motion of anion and promote the formation of NaF-rich solid electrolyte interphase, resulting in excellent cycling stability at relatively high current density under quasisolid environment. In the meantime, the M-GSS/Na anode exhibits excellent dendrite inhibition ability and cycling stability. Therefore, with the synergistic effect of QPE and M-GSS/Na, constructed Na-O2 batteries run more stably and exhibit a low potential gap (0.166 V) after an initial 80 cycles at 1,000 mA g-1 and 1,000 mAh g-1. This work provides the reference basis for building quasisolid state Na-O2 batteries with long-term cycling stability.