Ammonium Research Articles

Exogenous Metal Cations in the Synthesis of CsPbBr3 Nanocrystals and Their Interplay with Tertiary Amines.

Current syntheses of CsPbBr3 halide perovskite nanocrystals (NCs) rely on overstoichiometric amounts of Pb2+ precursors, resulting in unreacted lead ions at the end of the process. In our synthesis scheme of CsPbBr3 NCs, we replaced excess Pb2+ with different exogenous metal cations (M) and investigated their effect on the synthesis products. These cations can be divided into two groups: group 1 delivers monodisperse CsPbBr3 cubes capped with oleate species (as for the case when Pb2+ is used in excess) and with a photoluminescence quantum yield (PLQY) as high as 90% with some cations (for example with M = In3+); group 2 yields irregularly shaped CsPbBr3 NCs with broad size distributions. In both cases, the addition of a tertiary ammonium cation (didodecylmethylammonium, DDMA+) during the synthesis, after the nucleation of the NCs, reshapes the NCs to monodisperse truncated cubes. Such NCs feature a mixed oleate/DDMA+ surface termination with PLQY values of up to 97%. For group 1 cations this happens only if the ammonium cation is directly added as a salt (DDMA-Br), while for group 2 cations this happens even if the corresponding tertiary amine (DDMA) is added, instead of DDMA-Br. This is attributed to the fact that only group 2 cations can facilitate the protonation of DDMA by the excess oleic acid present in the reaction environment. In all cases studied, the incorporation of M cations is marginal, and the reshaping of the NCs is only transient: if the reactions are run for a long time, the truncated cubes evolve to cubes.

Anethole Regulated Crystallization for High Efficiency Carbon‐Based Perovskite Solar Cells

AbstractTwo‐step sequential deposition is a widespread technique for the fabrication of perovskite films, renowned for its better control of the crystallization process. However, achieving a well‐controlled and complete reaction of PbI2 by organic ammonium salts remains a key challenge. Previous studies have predominantly focused on regulating the properties of the PbI2 layer while paying less attention to the high reactivity of organic ammonium salts. In this study, the natural molecule anethole is first explored to control perovskite crystallization during two‐step sequential deposition, focusing on the reactivity modulation of organic formamidine ion (FA+). It is demonstrated that FA+ exhibits strong hydrogen bond interactions with anethole, inhibiting the high reactivity of FA+ and effectively delaying the rapid reaction between FAI and PbI2. This decelerates the crystallization kinetics of perovskite films, facilitating the orderly and complete reaction of PbI2 by FAI while suppressing detrimental δ‐phase formation. Consequently, FA‐based perovskite films with high crystallinity, preferred orientation, and low defect state density are obtained. The fabricated planar hole transport layer‐free carbon electrode perovskite solar cells deliver an efficiency of 20.41% (certified efficiency of 20.0%), which is a new record for this kind of solar cell.

A Comprehensive Review of Ammonium Ion Hybrid Supercapacitors: Exploring Recent Breakthroughs and Future Horizons

A Comprehensive Review of Ammonium Ion Hybrid Supercapacitors: Exploring Recent Breakthroughs and Future Horizons

Cover Picture

4‐(2‐Hydroxyethyl)piperazin‐1‐ium iodide (PZOI) is a functional ammonium salt that can simultaneously reduce shallow/deep‐level defect densities by passivation effect and form 2D component, respectively. These advances reduce the energy loss of single‐junction devices and significantly enhance the efficiency and stability of perovskite/organic tandems. More details are discussed in the article by Li et al. on page 1819—1827.image

Comparative proteomics analysis of root and nodule mitochondria of soybean.

Legumes perform symbiotic nitrogen fixation through rhizobial bacteroids housed in specialised root nodules. The biochemical process is energy-intensive and consumes a huge carbon source to generate sufficient reducing power. To maintain the symbiosis, malate is supplied by legume nodules to bacteroids as their major carbon and energy source in return for ammonium ions and nitrogenous compounds. To sustain the carbon supply to bacteroids, nodule cells undergo drastic reorganisation of carbon metabolism. Here, a comprehensive quantitative comparison of the mitochondrial proteomes between root nodules and uninoculated roots was performed using data-independent acquisition proteomics, revealing the modulations in nodule mitochondrial proteins and pathways in response to carbon reallocation. Corroborated our findings with that from the literature, we believe nodules preferably allocate cytosolic phosphoenolpyruvates towards malate synthesis in lieu of pyruvate synthesis, and nodule mitochondria prefer malate over pyruvate as the primary source of NADH for ATP production. Moreover, the differential regulation of respiratory chain-associated proteins suggests that nodule mitochondria could enhance the efficiencies of complexes I and IV for ATP synthesis. This study highlighted a quantitative proteomic view of the mitochondrial adaptation in soybean nodules.

Strong Enhancement in Cobalt(II) TPMA Aqueous Hydrogen Photosynthesis through Intramolecular Proton Relay.

Photosynthetic hydrogen generation by cobalt(II) tris(2-pyridilmethyl)amine (TPMA) complexes is mainly limited by protonation kinetics and decomposition routes involving demetallation. In the present work we have explored the effects of both proton shuttles and improved rigidity on the catalytic ability of cobalt(II) TPMA complexes. Remarkably, we demonstrate that, while a small enhancement in the catalytic performance is attained in a rigid cage structure, the introduction of ammonium groups as proton transfer relays in close proximity to the cobalt center allows to reach a 4-fold increase in the quantum efficiency of H2 formation, and a surprising 22-fold gain in the maximum turnover number, at low catalyst concentration. The beneficial role of the ammonium relays in promoting faster intramolecular proton transfer to the reduced cobalt center is documented by transient absorption spectroscopy, showcasing the great relevance of tuning the catalyst periphery to achieve efficient catalysis of solar fuel formation.

Strong Enhancement in Cobalt(II) TPMA Aqueous Hydrogen Photosynthesis through Intramolecular Proton Relay

Photosynthetic hydrogen generation by cobalt(II) tris(2‐pyridilmethyl)amine (TPMA) complexes is mainly limited by protonation kinetics and decomposition routes involving demetallation. In the present work we have explored the effects of both proton shuttles and improved rigidity on the catalytic ability of cobalt(II) TPMA complexes. Remarkably, we demonstrate that, while a small enhancement in the catalytic performance is attained in a rigid cage structure, the introduction of ammonium groups as proton transfer relays in close proximity to the cobalt center allows to reach a 4‐fold increase in the quantum efficiency of H2 formation, and a surprising 22‐fold gain in the maximum turnover number, at low catalyst concentration. The beneficial role of the ammonium relays in promoting faster intramolecular proton transfer to the reduced cobalt center is documented by transient absorption spectroscopy, showcasing the great relevance of tuning the catalyst periphery to achieve efficient catalysis of solar fuel formation.

Graphene nanoribbon hydrogel scaffold for highly conductive and robust polyimide nanocomposite

Although highly loaded graphitic nanocarbon materials effectively enhance the electrical, mechanical, and thermal properties of polymeric materials, their practical implementation has been hindered by severe aggregation issues. Here, we propose a method to achieve homogeneous nanocarbon-polyimide (PI) composites by integrating graphene oxide nanoribbons (GONRs) with polyamic acid ammonium (PAA) salt, a precursor of PI. Self-assembled scaffold structure of GONRs hydrogel enables the uniform integration and immobilization of PAA within the GONR scaffold, mitigating aggregation concerns. The resulting GONR/PAA hydrogel, formed through physical interactions, can be coated onto substrates via a shear stress-induced bar coating method due to its viscoelastic rheological properties. Subsequent heat treatment at 400 °C triggers the imidization reaction of PAA and the reduction of GONR, facilitating the formation of uniformly integrated GNR/PI nanocomposite coatings. Under optimized conditions, incorporating a high-loading GONR content in PAA (95 wt% of GONR and 5 wt% of PAA) yielded GNR/PI composites with excellent mechanical properties, exhibiting a hardness of 0.75 GPa and an elastic modulus of 8.3 GPa. Additionally, this GNR/PI composite displayed a good electrical conductivity of 3890 S/m, attributed to the electrical pathways formed by GNRs within the PI matrix.

Structure-activity correlation for new phosphorylated quaternary ammonium salts: To antimicrobial activity via self-organization

The impact of the hydrocarbon tail length on the physicochemical properties of N-((diisopropoxyphosphoryl)methyl)-N,N-dimethyl-N-alkylammonium bromides (CnPN+Br-, where n = 10, 12, 14, 16, 18) was studied through surface tension, electrical conductivity, and spectral characteristics of hydrophobic probes (Orange OT, pyrene) measurements. In homologous series, the values of the critical micelle concentration (cmс) decrease and reach the micromolar range for hexadecyl and octadecyl derivatives. Surface tension isotherms were used to determine the maximum surface excess (Γmax), the minimum area per surfactant molecule at the air/water interface (Amin), and the Gibbs free energy of micelle formation (∆Gmic) and adsorption (∆Gad). Thermodynamic parameters (ΔGmic, ΔHmic, ΔSmic) and counterion binding degree values (β) were calculated from the temperature dependences of specific electrical conductivity on the CnPN+Br- concentration. It was established that micellization is a spontaneous and entropy-driven process. Additionally, aggregation numbers of CnPN+Br- were obtained from steady-state fluorescence quenching and dye solubilization techniques. It was established that the investigated cationic surfactants exhibit membranotropic activity against gram-positive bacteria Staphylococcus aureus, caused by depolarization of bacterial cytoplasmic membrane.

Bioconversion of Apple Pomace to Meyerozyma guilliermondii and Scheffersomyces stipitis Biomass

Poland is one of the leading apple-producing countries, both in Europe and around the world. One of the main byproducts of apple processing is pomace, which can account for 20–35% of the harvested apples. Pomace is a potential source of many valuable bioactive components and can also serve as a food ingredient, either directly or indirectly (after bioconversion with fodder yeast). This study aimed to evaluate the possibility of converting polysaccharides contained in apple pomace to yeast biomass. Meyerozyma guilliermondii and Scheffersomyces stipitis yeasts were grown in a medium prepared by pretreatment of the raw material with water or 2% sulphuric acid at 120 °C. Subsequently, enzymatic hydrolysis was performed using a Cellic CTec2 preparation at 30 °C or 50 °C. The resulting hydrolysates were enriched with ammonium salts, and shaken yeast cultures were incubated at 30 °C for 72 h. Based on the results, it can be concluded that acid pretreatment of apple pomace is more effective than water pretreatment under the same time and temperature conditions. The Meyerozyma guilliermondii strain grows in apple pomace hydrolysates more efficiently (16.29 g/L) than Scheffersomyces stipitis cells do (14.63 g/L).

Analysis of the Behavior of Deep Eutectic Solvents upon Addition of Water: Its Effects over a Catalytic Reaction.

This study presents the potential role of deep eutectic solvents (DESs) in a lipase-catalyzed hydrolysis reaction as a co-solvent in an aqueous solution given by a phosphate buffer. Ammonium salts, such as choline chloride, were paired with hydrogen bond donors, such as urea, 1,2,3-propanetriol, and 1,2 propanediol. The hydrolysis of p-nitrophenyl laureate was carried out with the lipase Candida antarctica Lipase B (CALB) as a reaction model to evaluate the solvent effect and tested in different DES/buffer phosphate mixtures at different % w/w. The results showed that two mixtures of different DES at 25 % w/w were the most promising solvents, as this percentage enhanced the activities of CALB, as evidenced by its higher catalytic efficiency (kcatKM). The solvent analysis shows that the enzymatic reaction requires a reaction media rich in water molecules to enable hydrogen-bond formation from the reaction media toward the enzymatic reaction, suggesting a better interaction between the substrate and the enzyme-active site. This interaction could be attributed to high degrees of freedom influencing the enzyme conformation given by the reaction media, suggesting that CALB acquires a more restrictive structure in the presence of DES or the stabilized network given by the hydrogen bond from water molecules in the mixture improves the enzymatic activity, conferring conformational stability by solvent effects. This study offers a promising approach for applications and further perspectives on genuinely green industrial solvents.

Study in the impact of quaternized graphene oxide (QGO) composition as modifier on the chemical, physical, mechanical, and performance properties of polyvinylidene fluoride (PVDF)-based nanocomposite membrane

Polyvinylidene Fluoride (PVDF) membranes were modified with quaternized graphene oxide (QGO) synthesized from graphene oxide and quaternized ammonium groups. PVDF/QGO membranes were created by blending PVDF and 0.01-0.05 g QGO via phase inversion. FTIR confirmed the successful QGO incorporation. PVDF/QGO membranes exhibited increased mechanical stiffness. Meanwhile, SEM revealed asymmetric morphology with surface and internal pores. AFM showed the membrane with 0.05 g and QGO had the highest surface roughness of 101.2 nm, which increased filtration area and flux. QGO improved hydrophilicity through hydroxyl and quaternary ammonium groups, enhancing water flux up to 1208 Lm?2h?1 for 0.05 g QGO. Cu2+ rejection increased to 75% for 0.05 g QGO membrane due to chelation and adsorption effects. PVDF/QGO membranes displayed bacterial growth inhibition, unlike pristine PVDF. The inhibition zone diameter increased with more QGO, indicating improved antibacterial activity. Overall, this study demonstrated that QGO improved PVDF membranes' hydrophilicity, antibacterial properties, and mechanical strength.

Preparation of an Antibacterial Branched Polyamide 6 via Hydrolytic Ring-Opening Co-Polymerization of ε-Caprolactam and Lysine Derivative.

In this study, we successfully realized the hydrolytic ring-opening co-polymerization of ε-caprolactam (CPL) and lysine derivative. A novel antibacterial modified polyamide 6 with a branched structure was obtained after the quaternization of the co-polymers. The co-polymers exhibited a significant increase in zero shear viscosity, melt index and storage modulus at the low frequency region. The quaternized co-polymers displayed thermal properties different from pure PA6 and good mechanical (tensile) properties. The antibacterial activity of the quaternized co-polymers depends on the quaternary ammonium groups' incorporated content. At 6.2 mol% incorporation of quaternary ammonium groups, the strong antibacterial activity has been introduced to the co-polymers. As the quaternary ammonium groups approached 10.1 mol%, the antibacterial polymers demonstrated nearly complete killing of Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative). The above research results provided a new approach for the study of high-performance nylon.

Fabrication of ionic liquid self-assemblies based on dicamba with improved herbicidal activity and reduced environmental risks

The off-target loss of pesticide formulations caused by volatilization and leaching has reduced effective utilization and increased risks to the ecological environment and human health. Self-assembly of pesticides has been widely concerned due to the improved bioactivity and environmental compatibility. Herbicidal ionic liquids (HILs) could effectively decrease off-target loss and increase efficacy and environmental safety by improving the physicochemical properties of herbicides. Herein, HILs were prepared by pairing dicamba with quaternary ammonium salts containing different alkyl chain lengths and aromatic groups and subsequently self-assembled into spherical nanoparticles (HIL NPs) via electrostatic interaction and hydrophobic effect. Compared with dicamba, the obtained HIL NPs with an average particle size of 6–55 nm exhibited improved physicochemical properties, including high zeta potential values (+20.3 to +27.8 mV), low volatilization rate (2.4–3.9 %) and surface tension (22.83–33.07 mN m−1), decreased contact angle (32.25–41.55°) and leaching potential (76.2–86.5 %), and high soil adsorption (12.1–23.8 %), suggesting low risks to the environment. The control efficacy against Amaranthus retroflexus of HIL3 NPs pairing dicamba with octadecyl-trimethyl ammonium chloride was better than that of dicamba sodium salt at different concentrations. Therefore, the ionic liquid self-assembly developed by a facile and green preparation approach to reduce the volatility and leaching of pesticides would have enormous potential in sustainable agriculture.

Inside Back Cover: Chiral Tetrakis Eu(III) Complexes with Ammonium Cations for Improved Circularly Polarized Luminescence

Inside Back Cover: Chiral Tetrakis Eu(III) Complexes with Ammonium Cations for Improved Circularly Polarized Luminescence

Potentiometric ion-selective membrane sensing of microbially induced calcite precipitation

Microbially induced calcite precipitation (MICP) is an emerging biogeotechnical technique that facilitates a bio-cementation process through biomineralisation and which can bond otherwise loose soil particles, thereby increasing the shear strength and stiffness of the soil while decreasing its permeability and compressibility. However, the uniformity of calcite (calcium carbonate) precipitation may have a relatively low ‘certainty of execution’ in situ due to strict environmental conditions required for the reaction, highlighting a strong need for in situ monitoring of the subsurface during and following the treatment. This research explored an electrochemical approach to monitoring MICP treatment through the development and use of potentiometric ion-selective sensors to measure ammonium and calcium ions continuously in both aqueous batch reactors and small laboratory-scale soil test cells. Sensor calibrations indicate a strong and reliable correlation between the electrochemical potential and target ion concentration, which shows promise in sensor technology for monitoring MICP and other similar processes. Improvements to the current design are, however, needed, as fouling due to calcite precipitation, and to some extent biofouling of the sensor, was observed in the highly dynamic, biomineralisation environment, which caused data drift/interference. These effects should be considered in data analysis and eliminated/minimised for eventual adoption towards monitoring the efficacy of MICP treatment in situ.

Anionic Hofmeister Effect Regulated Conductivity in Polyelectrolyte Hydrogels for High-Performance Supercapacitor.

The Hofmeister effect not only affects the stability and solubility of protein colloids but also has specific effects on the polymer molecules. Here, the impact of the Hofmeister effect on the electrochemical properties of polyelectrolyte hydrogels at room temperature and subzero temperature studied for the first time. Polyelectrolyte hydrogels exhibit an anti-polyelectrolyte effect in low concentrations of ammonium salt, while they exhibit an obvious Hofmeister effect in high concentrations of ammonium salt. Kosmotropic ions demonstrate strong interaction with water molecules or polymer chains, resulting in the reduction of conductivity of polyelectrolyte hydrogels. However, chaotropic ions exhibit weak interactions with water molecules or molecular chains, leading to an increase in conductivity. The Hofmeister effect has a more significant effect on the polyzwitterion electrolyte. The conductivity of polyzwitterion hydrogel soaked in chaotropic ion is up to 6.2 mS cm-1 at -40°C. The supercapacitor assembled by polyzwitterion electrolytes maintains a capacitance retention rate of 85% and ≈100% coulomb efficiency after 15 000 cycles at -40°C. This study elucidates the influence of the Hofmeister effect on conductivity in polyelectrolytes and expands the regulatory approach for improving the performance of energy storage devices.

Surface-Functionalized Nano-Montmorillonite and Its Application as Crude Oil Flow Improver

In view of the problem of poor flowability in the production and transportation of high-wax crude oil and high-viscosity crude oil, crude oil flow improvers are commonly used to reduce their viscosity and pour point. Although polymer-based crude oil flow improvers are highly effective in improving crude oil flowability, there are still problems such as high cost and the need for a large amount of solvent dilution when used. In this work, highly dispersed organic modified nano-montmorillonite was prepared by using Na-based montmorillonite and quaternary ammonium salts, and the influencing factors on the viscosity of the crude oil were investigated. The most effective modified nano-montmorillonite (B@MMT) can reduce the viscosity by 96.7% (21 °C) and depress the pour point by 15 °C. Furthermore, it has shown a high improvement in flowability in the other four different sources of crude oil, with viscosity reduction rates of 52.2, 93.4, 79.1 and 67.4%, respectively. B@MMT was characterized by FTIR, SEM, zeta potential and contact angle. Based on DSC and wax crystal structure analysis, the mechanism of the influence of B@MMT on crude oil viscosity and pour point was explored. Finally, the cost of B@MMT was estimated, and the result shows that, compared with the crude oil flow improver in use, B@MMT has considerable commercial competitive advantages.

Surface-Functionalized Nano-Montmorillonite and Its Application as Crude Oil Flow Improver

In view of the problem of poor flowability in the production and transportation of high-wax crude oil and high-viscosity crude oil, crude oil flow improvers are commonly used to reduce their viscosity and pour point. Although polymer-based crude oil flow improvers are highly effective in improving crude oil flowability, there are still problems such as high cost and the need for a large amount of solvent dilution when used. In this work, highly dispersed organic modified nano-montmorillonite was prepared by using Na-based montmorillonite and quaternary ammonium salts, and the influencing factors on the viscosity of the crude oil were investigated. The most effective modified nano-montmorillonite (B@MMT) can reduce the viscosity by 96.7% (21 °C) and depress the pour point by 15 °C. Furthermore, it has shown a high improvement in flowability in the other four different sources of crude oil, with viscosity reduction rates of 52.2, 93.4, 79.1 and 67.4%, respectively. B@MMT was characterized by FTIR, SEM, zeta potential and contact angle. Based on DSC and wax crystal structure analysis, the mechanism of the influence of B@MMT on crude oil viscosity and pour point was explored. Finally, the cost of B@MMT was estimated, and the result shows that, compared with the crude oil flow improver in use, B@MMT has considerable commercial competitive advantages.

Anionic Hofmeister Effect Regulated Conductivity in Polyelectrolyte Hydrogels for High-Performance Supercapacitor.

The Hofmeister effect not only affects the stability and solubility of protein colloids but also has specific effects on the polymer molecules. Here, the impact of the Hofmeister effect on the electrochemical properties of polyelectrolyte hydrogels at room temperature and subzero temperature studied for the first time. Polyelectrolyte hydrogels exhibit an anti-polyelectrolyte effect in low concentrations of ammonium salt, while they exhibit an obvious Hofmeister effect in high concentrations of ammonium salt. Kosmotropic ions demonstrate strong interaction with water molecules or polymer chains, resulting in the reduction of conductivity of polyelectrolyte hydrogels. However, chaotropic ions exhibit weak interactions with water molecules or molecular chains, leading to an increase in conductivity. The Hofmeister effect has a more significant effect on the polyzwitterion electrolyte. The conductivity of polyzwitterion hydrogel soaked in chaotropic ion is up to 6.2 mS cm-1 at -40°C. The supercapacitor assembled by polyzwitterion electrolytes maintains a capacitance retention rate of 85% and ≈100% coulomb efficiency after 15 000 cycles at -40°C. This study elucidates the influence of the Hofmeister effect on conductivity in polyelectrolytes and expands the regulatory approach for improving the performance of energy storage devices.