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The ionic pair self-assembly (IPSAM) composed of poly(ethyleneimine) (PEI) and (phenylthio)acetic acid (PTA) was prepared and the effect of phenolic acids (PAs) (e.g. cinnamic acid (CA), hydroxycinnamic acid (HCA), and dihydroxycinnamic acid (DHCA)) on the upper critical solution temperature (UCST) and the temperature-responsive releasing property of IPSAM were investigated. PEI/PTA ionic pair showed a UCST behavior and the PAs decreased the UCST effective in the order of DHCA > HCA > CA. The PAs were thought to attach to the PEI chain of PEI/PTA ionic pair as pendants. According to the interfacial tensiometry, PEI/PTA(3/7) ionic pair was found to be air/water interface-active due to their amphiphilic property. CA had little effect on the interfacial activity of the ionic pair. HCA and HDCA significantly decreased the interfacial activity possibly because they are more polar than CA thus the hydrophilic and lipophilic balance of PEI/PTA ionic pair could be broken by their attachment to PEI chains. IPSAM was found as nanoparticles whose diameter was tens of nanometer and PAs had little effect on the shape and the size of IPSAM, once the UCST of PEI/PTA/PA ionic pair was above room temperature where the TEM micrographs were taken. If the UCST of PEI/PTA/PA ionic pair was below room temperature, no particulate matters were found on the TEM micrographs. The release degree of cargo loaded in IPSAM increased slowly with time lapse below UCST. Whereas, the release degree increased rapidly with time lapse above UCST, possibly because of the thermally-induced disintegration of IPSAM.

We report a new facile light-induced strategy to disperse micron-sized aggregated bulk covalent organic frameworks (COFs) into isolated COFs nanoparticles. This was achieved by a series of metal-coordinated COFs, namely COF-909-Cu, -Co or -Fe, where for the first time the diffusio-phoretic propulsion was utilized to design COF-based micro/nanomotors. The mechanism studies revealed that the metal ions decorated in the COF-909 backbone could promote the separation of electron and holes and trigger the production of sufficient ionic and reactive oxygen species under visible light irradiation. In this way, strong light-induced self-diffusiophoretic effect is achieved, resulting in good dispersion of COFs. Among them, COF-909-Fe showed the highest dispersion performance, along with a drastic decrease in particle size from 5 μm to 500 nm, within only 30 min light irradiation, which is inaccessible by using traditional magnetic stirring or ultrasonication methods. More importantly, benefiting from the outstanding dispersion efficiency, COF-909-Fe micro/nanomotors were demonstrated to be efficient in photocatalytic degradation of tetracycline, about 8 times faster than using traditional magnetic stirring method. This work opens up a new avenue to prepare isolated nanosized COFs in a high-fast, simple, and green manner.

Diphenyl carbonate (DPC) is one of the versatile carbonates, and is often used for the production of polycarbonates. In recent years, the catalytic synthesis of DPC has become an important topic but the development of a highly active metal-free catalyst is a great challenge. Herein, a series of ionic liquids-SBA-15 hybrid catalysts with different functional groups have been developed for the synthesis of DPC under solvent-free condition, which are effective and clean instead of the metal-containing catalysts. It is found that in the presence of [SBA-15-IL-OH]Br catalyst, methyl phenyl carbonate (MPC) conversion of 80.5% along with 99.6% DPC selectivity is achieved, the TOF value is thrice higher than the best value reported by using transition metal-based catalysts. Moreover, the catalyst displays remarkable stability and recyclability. This work provides a new idea to design and prepare eco-friendly catalysts in a broad range of applications for the green synthesis of carbonates.

Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure (0.1 MPa) without any solvent and co-catalyst leading to 96.1% product yield. It can be reused five times to keep the product yield over 90%. These intriguing results are attributed to a new reaction mechanism, which is supported by theoretical calculations along with the measurements of 13C NMR spectrum and Fourier transform infrared spectroscopy (FT-IR). The excellent catalytic activity can be traced to a CO2-philic group along with an electrophilic hydrogen atom. Our work shows that incorporation of CO2-philic group is an feasible pathway to develop the new efficient ionic liquids.

As a promising cathode material, Na3V2(PO4)2F3 (NVPF) has attracted wide attention for sodium-ion batteries (SIBs) because of its high operating voltage and high structural stability. However, the low intrinsic electronic conductivity and insufficient Na ion mobility of NVPF limit its development. Herein, K-doping NVPF is prepared through a facile ball-milling combined calcination method. The effects of K-doping on the crystal structure, kinetic properties and electrochemical performance are investigated. The results demonstrate that the Na2.90K0.10V2(PO4)3F3 (K0.10-NVPF) exhibits a high capacity (120.8 mAh g−1 at 0.1 C), high rate capability (66 mAh g−1 at 30 C) and excellent cycling performance (a capacity retention of 97.5% at 1 C over 500 cycles). Also, the occupation site of K ions in the lattice, electronic band structure and Na-ion transport kinetic property in K-doped NVPF are investigated by density functional theory (DFT) calculations, which reveals that the K-doped NVPF exhibits improved electronic and ionic conductivities, and located K+ ions in the lattice to contribute to high reversible capacity, rate capability and cycling stability. Therefore, the K-doped NVPF serves as a promising cathode material for high-energy and high-power SIBs.

Highly durable and stretchable ionic conductors are indispensable components for flexible electronics. However, fabricating such ionic conductors that are also non-toxic and biodegradable remains a...

The specific crystalline form of a compound remarkably affects its physicochemical properties. Therefore, a detailed analysis of the structural features and intermolecular interactions of a multi-component crystal is feasible to understand the relationships among the structure, physicochemical properties and the formation mechanism. In the present study, three novel cocrystal salt solvates of rhein and berberine were reported for the first time. Various solid characterizations and theoretical computations based on density functional theory (DFT) were carried out to demonstrate the intermolecular interactions. The theoretical computation shows that the strongest interaction existed between berberine cation and rhein anion, and the electrostatic interaction play a dominant role. However, no salt bond was observed between them. Further intrinsic dissolution rate analysis in water shows that the monohydrate exhibits 17 times enhancement in comparison with rhein. The rhein and berberine combined in ionic state in cocrystal salt is the main reason for the solubility improvement. This paper suggests that the interactions between the different components can be visualized and qualitatively and quantitatively analyzed by theoretical computation, which is helpful to understand the relationship between stereochemical structure and physicochemical properties of multi-component complex.

Kinetics and mechanism of the oxygen reduction reaction (ORR) in an alkaline medium have been studied on La2BO4±δ (B: Ni, Co or Mn) various mixed conducting oxides (MIEC: mixed electronic and ionic conductor). The preparation of these materials was carried out using the citrate method. The purity, the surface chemical state and the morphology were investigated by X-ray diffraction, X-ray photon-electron spectrometry (XPS) and scanning electron microscopy, respectively. An iodometric titration was also performed to evaluate the oxygen (over)-stoichiometry. The catalytic activity of the La2NiO4±δ (L2NO), La2CoO4±δ (L2CO) and La2MnO4±δ (L2MO) oxides towards ORR in alkaline medium was evaluated using the rotating disc electrode in 0.5 M NaOH solution completed by various electrochemical techniques such as cyclic voltammetry, linear voltammetry, the Koutecky–Levich diffusion model and impedance spectroscopy. The La2NiO4±δ sample is pure and more porous, but the La2CoO4±δ and La2MnO4±δ samples show secondary phases and are less porous. The XPS analysis shows that the surface of the La2NiO4±δ material is rich in hydroxide ions (OH−) and the Ni3+/Ni2+ ratio is very low unlike La2CoO4±δ and La2MnO4±δ materials in which OH¯ are low. Porosity and percentages of OH¯ and B3+/B2+ ratio are parameters influencing the ORR mechanism and therefore favouring, for this purpose, a one-step mechanism on La2NiO4+δ and a two-step mechanism on La2CoO4±δ and La2MnO4±δ electrocatalysts. Graphic abstract: [Figure not available: see fulltext.]

Applying mixed oxygen ionic and electronic conducting (MIEC) oxides as the cathode offers a promising solution to enhance the performance of solid oxide fuel cells (SOFCs). However, the phase instability in CO2-containing air and sluggish oxygen reduction activity of MIEC cathodes remain a long-term challenge for optimizing the electrochemical performance of SOFCs. Herein, a heterovalent co-doping strategy is proposed to enhance the oxygen reduction activity and CO2 tolerance of SOFCs cathodes, which can be demonstrated by developing a novel BaCo0.6Fe0.4O3-δ (BCF)-based MIEC oxide, BaCo0.6Fe0.2Sn0.1Y0.1O3-δ (BCFSY). In addition to improving the stability of BCF-based perovskites, this strategy achieves an optimized balance of ionic mobility and oxygen vacancies due to the synergies between the effects of the co-dopants. Compared with single-doped materials, BCFSY exhibits improved CO2 tolerance and considerably higher ORR activity, which is reflected in a significantly lower polarization resistance of 0.15 Ω cm2 at 600°C. The results of this work provide an efficient tactic for designing electrode materials for SOFCs.

The purpose of this work is to study the influence of the immersion temperature and the treatment time of the ion exchange of soda-lime glass in molten KNO3 bath on its mechanical properties, and in particular the erosion resistance using Sahara sand and alumina abrasives. EDS analysis showed that the depth of penetration of K+ into glass increases as temperature and treatment time increase. The effect of ion exchange temperature and time on mechanical reinforcement was studied by micro-indentation, scratch test, wear and erosion test. All of these mechanical properties are improved after ion exchange treatments; erosion and wear resistance behave the same, either by using natural abrasives such as Sahara sand or by using an aggressive abrasive as alumina grits. The increase in the ion exchange time induces an increase in Vickers hardness of about 15–40% compared to annealed glass. Samples processed at 520 °C for a short period of 2 h show better mechanical properties compared to samples processed at 480 °C for longer times. In this case, the sample has a higher surface density which made the glass in compression not only because the potassium ions occupy the ionic substitution spaces but also the free spaces.

Off-stoichiometry of perovskite structural Bi0.5Na0.5TiO3 (BNT) ferroelectrics can give rise to considerable oxide-ion conductivity. The inherent structural characteristics are urgent to be resolved due to its particular sensitivity of the conduction mechanism to the nominal composition and synthesis process. Herein, a thorough study of the temperature-dependent neutron, X-ray diffraction and Raman spectrum is carried out on a series of equivalently substituted A-site deficient non-stoichiometric and pristine BNT. Phase transition and defect association are systemically investigated in these dominated rhombohedral phases at room temperature, associated with well saturated ferroelectric states. Significant structural evolution identified by Rietveld refinements and the origin of the electrical performance are clarified at elevated temperatures, focusing on the subtle distortions of ionic displacements, oxygen octahedral tilts and local chemical environments for oxygen vacancies. The ion migration ability mediated by oxygen vacancies that are not energetically favorable in BNT mainly depends on the external substitutional disorder, and is strongly affected by the dopant concentration. Together with the lone pair substitution concept, superior oxide ionic conductivity is achieved, and an alternative strategy is provided in designing BNT based oxide ion conductors.

Interface wettability is a vital role in directly impacting the electrical contact characteristics of oxides/Cu-based composites under arc erosion. Exploring its influence mechanism, especially at atomic/electronic scales, is significant but challenging for the rational design of oxides/Cu contacts. Here, we designed Zn2SnO4/Cu electrical contacts aiming to solve the poor wettability of SnO2/Cu composites. It was found that Zn2SnO4 could remarkably improve the arc resistance of Cu-based electrical contacts, which was benefited by the excellent interface wettability of Zn2SnO4/Cu. The characterization of eroded surface indicated that Zn2SnO4 particles distributed uniformly on the contact surface, leading to stable electrical contact characteristic. Nevertheless, SnO2 considerably deteriorated the arc resistance of SnO2/Cu composite by agglomerating on the surface. The effect mechanism of wettability on arc resistance was investigated through density function theory (DFT) study. It revealed that strong polar covalent bonds across the Zn2SnO4/Cu interface contributed to improving the interfacial adhesion strength/wettability and thus significantly enhanced the arc resistance. For binary SnO2/Cu interface, ionic bonds resulted in weak interface adhesion, giving rise to deterioration of electrical contact characteristic. This work discloses the bonding mechanism of oxide/Cu interfaces and paves an avenue for the rational design of ternary oxide/Cu-based electrical contact materials.

In this paper we present the effective strategy of Fe3+ and Li+ co-doping to enhance the electrostrain of ZnO thin films. Zn0.88(Fe0.06Li0.06)O thin film exhibits an excellent d33* value of 415 pm/V and large linear electrostrain of 0.68% after thermal-electric treatment. Both the X-ray diffraction and first principle calculation results have indicated that the Fe3+ and Li+ ions are inclined to adopt a preferential alignment along the edges approximately parallel to [001] direction in the zinc-oxygen tetrahedron and constitute a defect dipole (ionic pairs). It is considered that the local lattice distortion and the electric field-triggered polarization extension and rotation generated by preferential distributed Fe3+-Li+ionic pairs are responsible for the outstanding piezoelectric properties and large linear electrostrain.

The external bacteria will inevitably invade the wound, attach, and subsequently colonize on the wound surface during surgery and biomedical operations, which slows down the process of wound healing and tissue repair, remaining a significant threat to human health. Therefore, developing a smart antibacterial surface has become the focus of antimicrobial research field, which has important social and economic significance. Herein, we present a simple route towards producing ionic interaction-driven switchable multifunctional antibacterial surfaces that decrease bacteria attachment and inactivate attached microorganisms. Briefly, the graded surface was constructed by surface-initiated atom transfer radical polymerization on silicon substrate consisting of antifouling component poly (3-sulfopropyl methacrylate potassium salt) (PSPMA) brushes, an antibacterial positive-charged components lysozyme (LYZ) and hexadecyl trimethyl ammonium bromide (CTAB) were loaded on negative-charged sulfonate groups via electrostatic interaction. The resultant brushes grafted surfaces exhibited more than ~95.5% bactericidal efficacy, and ~92.8% releasing rate after introducing contra-ions (Na+ & Cl-) against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. More importantly, the ionic interaction-driven method used in this work is straightforward to produce renewable antibacterial surfaces. To further extend the applications, we construct smart cotton fabric to develop Fabric-PSPMA/LYZ and Fabric-PSPMA/Chitosan brushes which can promote wound healing and tissue repair. This work will assist in the wider utilization of the switchable antibacterial functionalization of biomedical materials.

Solid-state electrolytes (SSEs), which replace flammable and toxic liquid electrolytes, have attracted widely attention. However, there exist still some challenges in actual application such as poor interfacial compatibility and slow ionic migration. In this study, MgO nanofibers and MgF2 nanofibers were prepared via the electro-blow spinning and high-temperature calcination methods, and were applied to all-solid-state lithium metal batteries for the first time. The organic-inorganic composite SSEs exhibited continuous conduction paths based on the virtue of the nanofibers with high length-to-diameter ratio, which were designed and prepared by mixing prepared fillers into the poly(ethylene oxide) (PEO)/ lithium bis(trifluoromethane) sulfonilimide (LiTFSI) system. The effect of filler with different morphologies, doping ratios and component on ionic conductivity, electrochemical stability and cycle performance were explored under two kinds of [EO]/[Li+] ratios and ambient temperatures. The ionic conductivities of electrolytes containing MgO and MgF2 nanofibers can reach up to 1.19×10−4 and 1.39×10−4 S cm−1 at 30 °C, respectively. They were attributed to specific ionic conductive enhancement at the organic-inorganic interface, reduced crystallinity and Lewis acid interaction, which can effectively promote the dissociation of the lithium salts. Especially MgF2 nanofiber, combining low electronic conductance, excellent electrochemical stability and outstanding inhibition for lithium dendrites of fluorides, endowed the battery with an initial specific capacity of 140.6 mAh g−1 and capacity decay rate per cycle of 0.055% after 500 cycles at 50 °C. The work can provide an idea to design SSE with fast and multi-dimensional Li conductive paths and excellent interfacial compatibility.

Functionalisation of technological nanopores and investigation of their transport properties have attracted considerable interest from scientific as from technological point of view, among others due to their potential regarding molecular transport design. Asymmetric design of nanopore structure and functionalisation is expected to trigger increased and directed transport of ionic species. Based on this motivation, we demonstrate a layer-selective polymer functionalisation in a mesoporous double layer thin film to generate nanoscale step gradient architectures with asymmetric charge distribution by taking advantage of co-condensation and polymer modification techniques. Thereby, mesoporous silica and co-condensed mesoporous amino silica thin films are combined to double layered films with a film thickness of 300 – 400 nm in both sequential arrangements, respectively. Iniferter initiated polymerisation is used to selectively functionalise only the amino silica layer with polymers such as poly(2-(methacryloyloxy)ethyltrimethylammonium chloride) (PMETAC) in a grafting from approach. Investigation of the ionic pore accessibility of the mesoporous double layered films before and after layer-selective polymer functionalisation shows that the ionic pore accessibility is dominated by the bottom layer when overcoming the electrostatic repulsion of the top layer.

We present a study of the structure and differential capacitance of electric double layers of aqueous electrolytes. We consider electric double layer capacitors (EDLC) composed of spherical cations and anions in a dielectric continuum confined between a planar cathode and anode. The model system includes steric as well as Coulombic ion-ion and ion-electrode interactions. We compare results of computationally expensive, but “exact” , Brownian Dynamics (BD) simulations with approximate, but cheap, calculations based on classical Density Functional Theory (DFT). Excellent overall agreement is found for a large set of system parameters, including variations in concentration, ionic size- and valency-asymmetries, applied voltages and electrode separation, provided the differences between the canonical ensemble of the BD simulations and the grand-canonical ensemble of DFT are properly taken into account. In particular, a careful distinction is made between the differential capacitance $$C_N$$ C N at fixed number of ions and $$C_\mu $$ C μ at fixed ionic chemical potential. Furthermore, we derive and exploit their thermodynamic relations. In the future these relations will also be useful for comparing and contrasting experimental data with theories for supercapactitors and other systems. The quantitative agreement between simulation and theory indicates that the presented DFT is capable of accounting accurately for coupled Coulombic and packing effects. Hence it is a promising candidate to cheaply study room temperature ionic liquids at much lower dielectric constants than that of water.

The super-structured nanodimensional apatitic particles have been limited explored for therapeutic applications. Furthermore, ion substituted super-structured nanodimensional apatitic particles have been rarely attempted, which motivated the present investigation. In the present work, F − and Cl − substituted hydroxyapatite (HAP) prepared via a facile and economical one-pot hydrothermal route were characterized for their structural, morphological and bioactive properties. The F − and Cl − anions (1 wt%) were individually substituted in hierarchically assembled nanostructured apatitic (HANA) particles and produced fluorine substituted Hydroxyapatite (FHAP) and chlorine substituted Hydroxyapatite (ClHAP) HANA particles, respectively. Besides comprehensive characterization, particles were systematically tested for their in-vitro ionic dissolution and drug-carrying abilities. Both FHAP and ClHAP nanoparticles exhibited monolithic apatitic structure, novel spherical morphology having substituted elements, mesoporous large surface area, and pore-volume with high thermal stability. Furthermore, both particles exhibited superior in-vitro bioactivity ability. Besides it, both FHAP and ClHAP nanoparticles exhibited superior drug loading and sustained drug release characteristics. Thus, this study presented the potentials of novel particle shapes with superior bioactivity and drug-carrying abilities, making them suitable for multipurpose therapeutic applications, including tissue regeneration and drug-carrying agents.

Solid electrolyte (SE) is the most crucial factor to fabricate safe and high-performance all-solid-state lithium-ion batteries. However, the most commonly reported SE, including solid polymer electrolyte (SPE) and inorganic oxides and sulfides, suffer problems of low ionic conductivity at room temperature for SPE and large interfacial impedance with electrodes for inorganic electrolytes. Here we for the first time demonstrate a novel ionic plastic crystal lithium salt solid electrolyte (OLiSSE) fast ion-conductor dilithium (1,3-diethyl-4,5-dicarboxylate) imidazole bromide with ordered Li-ion conductive nanopathways and an exceptional ionic conductivity of 4.4 × 10−3 S cm−1 at 30 °C. The prepared OLiSSE exhibits apparent characters of typical ionic plastic crystals in the temperature range of −20 to 70 °C, and shows remarkable thermal stability and electrochemical stability below 150 °C and 4.7 V, respectively. No lithium dendrite or short circuit behavior is detected for the Li|OLiSSE|Li cell after the galvanostatic charge-discharge test for 500 h. The fabricated Li|OLiSSE|LiFePO4 all-solid-state cell without using any separator and liquid plasticizer directly delivers an initial discharge capacity of 151.4 mAh g−1 at the discharge rate of 0.1 C, and shows excellent charge-discharge cycle stability, implying large potential application in the next generation of safe and flexible all-solid-state lithium batteries.

Metallic lithium (Li) is known to consider a critical role in next-generation rechargeable batteries. However, the uncontrolled growth of Li dendrites result in low Coulombic efficiency and safety issues in applications of Li metal batteries. High capacity and stable dense deposits of lithium metal are of great significant for high energy density battery. Herein, we propose a suitable degree of substitution for Carboxymethylcellulose Lithium (CMC-Li) as an artificial SEI layer, which has a high ionic transference number (0.66), high Young's modulus (24.6 GPa) and good lithiophilicity, then it can adapt to the volume changes of the lithium anode, enable superdense lithium deposits on Cu collector. The metallic lithium anode with CMC-Li films (CMC-Li@Li) delivers excellent cycling performance in the symmetrical cell at a large current density of 10 mA cm−2 and an areal capacity of 10 mAh cm−2 for almost 300 h. Moreover, the CMC-Li@Li||NCM613 full cell (N/P=2) delivers an initial specific capacity of 165 mAh g−1 with a high retention of 80% after 200 cycles.

The advancement of electrolyte systems has enabled the development of high-performance Li metal batteries (LMBs), which have tackled intractable dendritic Li growth and irreversible Li plating/stripping. In particular, the robust electrode–electrolyte interfaces created by electrolyte additives inhibit the deterioration of the cathode and the Li metal anode during repeated cycles. This paper reports the application of electrode–electrolyte interface modifiers, namely lithium nitrate (LiNO3) and lithium difluoro(bisoxalato) phosphate (LiDFBP) as a N donor and F donor, respectively. LiDFBP and LiNO3 with different electron-accepting abilities construct a mechanically robust, LiF-rich inner solid electrolyte interphase (SEI) and ion-permeable, Li3N-containing outer SEI layers on the Li metal anode, respectively. A well-structured dual-layer SEI capable of transporting Li+ ions is formed on the Li metal anode, while the cathode–electrolyte interface (CEI) on the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode is strengthened. Ether-based electrolytes containing LiDFBP and LiNO3 lead to a long cycle life (600 cycles) of Li|NCM811 full cells at C/2 with 80.9% capacity retention and a high Coulombic efficiency (CE) of 99.94%. Structural optimization of the SEI and CEI provides an opportunity for advancing the practical uses of LMBs.

Lithium metal is deemed as an ideal anode material in lithium-ion batteries because of its ultrahigh theoretical specific capacity and the lowest redox potential. However, the rapid capacity attenuation and inferior security resulting from the dendritic lithium growth severely limit its commercialization. Herein a novel hybrid gel polymer electrolyte (GPE) based on electrospun lithium sulfonated polyoxadiazole (Li-SPOD) nanofibrous membrane swelled by lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) ether liquid electrolyte is proposed to address the issue of lithium dendrites. The Li-SPOD membrane synthesized by a simple one-pot method exhibits excellent mechanical strength and thermal resistance due to its high molecular weight and rigid backbone. The electron-withdrawing oxadiazole ring and oxadiazole ring-Li+ complex, and N, O heteroatoms with lone pairs of electrons in Li-SPOD macromolecular chains facilitate the dissociation of -SO3Li group and Li+ transference. The hybrid Li-SPOD GPE exhibits both a high lithium-ion transference number (0.64) and high ionic conductivity (2.03 mS/cm) as well as superior interfacial compacity with lithium anodes. The LiFePO4-Li cell using this novel GPE can operate steadily at 2 C for 300 cycles, remaining a high discharge capacity of 125 mAh/g and dendrite-free anode. Remarkable performance improvements for the Li-Li and Cu-Li cells are also presented.

This article contributes a broad analysis of the latest improvement on energy storage operations using single layer surface modified graphene oxide (GO). GO, a thin structure of graphite oxide, is a modified graphene, holding several oxygen-casing functional groups. This provides GO with numerous distinctive features for multipurpose applications in capacitors, fuel cells and batteries. Precise applications are distinguished primarily comprising use in electrodes as the dynamic substantial’s to augment the recital or as substrates to discriminate the configurations, in solid-state solution and membranes techniques to advance the ionic attraction and other behaviors, and in internal structure layers to guard the current collectors, membranes or electrodes. Additionally, the problems, difficulties and looming overlooks are conferred in the article for promising promotes research development of GO applications.

Hypothesis Some of the most promising fields of application of ionic liquid-based colloids imply elevated temperatures. Their careful design and analysis is therefore essential. We assume that tuning the structure of the nanoparticle-ionic liquid interface through its composition can ensure colloidal stability for a wide temperature range, from room temperature up to 200 °C. Experiments The system under study consists of iron oxide nanoparticles (NPs) dispersed in ethylmethylimidazolium bistriflimide (EMIM TFSI). The key parameters of the solid-liquid interface, tuned at room temperature, are the surface charge density and the nature of the counterions. The thermal stability of these nanoparticle dispersions is then analysed on the short and long term up to 200 °C. A multiscale analysis is performed combining dynamic light scattering (DLS), small angle X-ray/neutron scattering (SAXS/SANS) and thermogravimetric analysis (TGA). Findings Following the proposed approach with a careful choice of the species at the solid-liquid interface, ionic liquid-based colloidal dispersions of iron oxide NPs in EMIM TFSI stable over years at room temperature can be obtained, also stable at least over days up to 200 °C and NPs concentrations up to 12 vol% ( ≈ 30 wt%) thanks to few near-surface ionic layers.

Doping modification is commonly used to improve the electrical properties of BaTiO3 (BT). In this study, the ((1-x)BT-x(Bi2O3–La2O3)) ceramics were synthesised to investigate the charge balance compensation mechanisms of BT ceramics co-doped with La2O3 and Bi2O3 as donors at A-site. The XRD results showed that a pseudo-cubic phase was formed by intruding dopants. The Raman spectroscopy revealed that the samples, which x = 0.10 and 0.16, had relatively more oxygen and titanium vacancies. After heat-treatment the samples in oxygen atmosphere, the dielectric constant of the sample with x = 0.10 was higher than that of the untreated, but for x = 0.16, it was almost no changed. These results indicated that the different charge balance compensation mechanism was exist in the samples with x = 0.10 and 0.16. Impedance measurements showed that the resistance tendency exhibited initial decrease and subsequent increase, leading to the electronic and ionic compensation mechanisms with x = 0.10 and 0.16, respectively. Ferroelectric properties also implied charge balance compensation mechanism transition, due to Ps and Pr were higher for x = 0.10 than for x = 0.16, respectively. This work provides a new strategy for modulating the electric properties of BT-based ceramics.

The development of a microcantilever (MCL) sensing device capable of simultaneously detecting several metal ionic species in aqueous media with low limits of detection requires a variety of sensing layers that are ion specific. Calix[4]arenes are robust molecules that can be easily modified and have been extensively studied for their ion binding properties. They are also capable of forming self-assembled monolayers (SAMs) on the gold layers of MCLs and are capable of detecting various metal ions with different anionic counterions in aqueous solutions. In this paper, we report on the effect of the alkoxy group in the narrow rim [O-(alkoxycarbonyl)methoxy] substituents of bimodal calix[4]arenes, which have been used as metal ion MCL sensing layers, using classical solution state experimental studies. A DFT computational study to compare the experimental results with several metal ions is also reported herein.

Anion exchange membrane fuel cells (AEMFCs) attract considerable attention owing to their high-power density and potential utilization of cheap non-noble metal catalysts. However, anion exchange membranes (AEMs) still face the problems of low conductivity, poor dimensional and chemical stability. To address these issues, AEMs with clustered piperidinium groups and ether-bond-free poly(terphenylene) backbone (3QPAP-x, x = 0.3, 0.4, and 0.5) were designed. Transmission electron microscope results show that the clustered ionic groups are responsible for fabricating well-developed conductive nanochannels and restraining the swelling behavior of the membranes. 3QPAP-0.4 and 3QPAP-0.5 AEMs exhibit higher conductivity (117.5 mS cm−1, 80 °C) and lower swelling ratio than that of commercial FAA-3-50 (80.4 mS cm−1, 80 °C). The conductivity of 3QPAP-0.5 only decreased by 10.4% after treating with 1 M NaOH at 80 °C for 720 h. The Hofmann elimination degradation of the cationic groups is restrained by the long flexible alkyl chain between cations. Based on the high performance of 3QPAP-0.5, an H2-O2-type AEMFC reaches 291.2 mW cm−2 (60 °C), which demonstrates that the as-prepared AEMs are promising for application in fuel cells.

Two garnet-structured Ca3MgBGe3O12 (B = Zr, Sn) ceramics with tetravalent cations at B-site were prepared by conventional solid state reaction. The crystal structure, microstructure evolution, and microwave dielectric performance were investigated using X-ray powder diffraction, Rietveld refinement, scanning electron microscopy, Raman spectroscopy, and infrared spectroscopy techniques. Dense Ca3MgZrGe3O12 and Ca3MgSnGe3O12 ceramics were obtained at sintering temperatures of 1420 and 1400 °C, respectively. The dielectric constant, unloaded quality factor, and temperature coefficient of resonance frequency of Ca3MgZrGe3O12 were 10.80 ± 0.2; 79,600 ± 1000 GHz (f = 12.61 GHz); and −66.8 ± 1 ppm/°C, respectively, and the corresponding values for Ca3MgSnGe3O12 were 9.68 ± 0.2; 83,400 ± 1000 GHz (f = 14.19 GHz); and −57.9 ± 1 ppm/°C, respectively. The dielectric performances of the two ceramics were compared by analyzing the ionic polarizability, packing fraction, and bond valence. The intrinsic dielectric properties were predicted by fitting the infrared reflectivity spectra.

Hypothesis One prevailing method to construct excellent temperature tolerance/long-lasting moisture hydrogels is to couple the original hydrogel networks with freezing-tolerant/moisture retaining agents, including ionic liquids, inorganic salts, zwitterionic osmolytes, and polyhydric alcohols. Among them, organohydrogels have shed new light on the development of ionic skins with long-term usability and stable sensing performance at subzero temperatures due to their long-lasting water retention and anti-freezing capability. Experiments We report a dual network organohydrogel by doping conductive ZnSO4 into the double network hydrogel of polyvinyl alcohol-polyacrylamide (PVA-PAM) with subsequent immersing in a mixed solvent of ethylene glycol (EG) and H2O. The anti-freezing and moisture retaining abilities of the PVA/PAM/Zn/EG (PPZE) organohydrogel were studied and the sensing performances of the PPZE organohydrogel-based ionic skin were investigated. Findings The organohydrogel exhibits a high conductivity (0.44 S m−1), excellent fatigue resistance and exceptional moisture retaining ability with more than 99.3% of the initial weight retention after 31 days storage at ambient temperature. Importantly, the PPZE organohydrogel-based ionic skin shows an ultra-low temperature anti-freezing ability and remains flexibility and sensing capability with a high sensitivity (signal response time ∼ 0.23 s) even at -50 °C. The PPZE organohydrogel demonstrates a tremendous potential in artificial skin and health monitoring.