High Stability Research Articles

Unlocking Cr3+-Cr3+ Coupling in Spinel: Ultrabroadband Near-Infrared Emission beyond 900 nm with High Efficiency and Thermal Stability.

Broadband near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) hold promising potential as next-generation compact, portable, and intelligent NIR light sources. Nonetheless, the lack of high-performance broadband NIR phosphors with an emission peak beyond 900 nm has severely hindered the development and widespread application of NIR pc-LEDs. This study presents a strategy for precise control of energy-state coupling in spinel solid solutions composed of MgxZn1-xGa2O4 to tune the NIR emissions of Cr3+ activators. By combining crystal field engineering and heavy doping, the Cr3+-Cr3+ ion pair emission from the 4T2 state is unlocked, giving rise to unusual broadband NIR emission spanning 650 and 1400 nm with an emission maximum of 913 nm and a full width at half-maximum (fwhm) of 213 nm. Under an optimal Mg/Zn ratio of 4:1, the sample achieves record-breaking performance, including high internal and external quantum efficiency (IQE = 83.9% and EQE = 35.7%) and excellent thermal stability (I423K/I298K = 75.8%). Encapsulating the as-obtained phosphors into prototype pc-LEDs yields an overwhelming NIR output power of 124.2 mW at a driving current of 840 mA and a photoelectric conversion efficiency (PCE) of 10.5% at 30 mA, rendering high performance in NIR imaging applications.

Synthesis and Photo/Radiation Chemical Characterization of a New Redox-Stable Pyridine-Triazole Ligand.

Photocatalysis using transition-metal complexes is widely considered the future of effective and affordable clean-air technology. In particular, redox-stable, easily accessible ligands are decisive. Here, we report a straightforward and facile synthesis of a new highly stable 2,6-bis(triazolyl)pyridine ligand, containing a nitrile moiety as a masked anchoring group, using copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction. The reported structure mimics the binding motif of uneasy to synthesize ligands. Pulse radiolysis under oxidizing and reducing conditions provided evidence for the high stability of the formed radical cation and radical anion 2,6-di(1,2,3-triazol-1-yl)-pyridine compound, thus indicating the feasibility of utilizing this as a ligand for redox active metal complexes and the sensitization of metal-oxide semiconductors (e.g., TiO2 nanoparticles or nanotubes).

Biological Activities, Biosorption of Heavy Metals, and Stability of Lipopeptide Biosurfactant Produced by the Alcaligenes aquatilis Bacterium YGD-2906

Background: Biosurfactants are natural products produced by microorganisms. This study examined the antioxidant activity, biosorption of heavy metals, and stability of lipopeptide biosurfactant (BLA 2906) produced by the Alcaligenes aquatilis bacterium YGD-2906. Methods: Biosurfactant production was determined by using four techniques: hemolytic test, emulsion indices, oil spreading test, and drop collapse test. The biosorption capacity of our biosurfactant to chelate the different heavy metals. The antioxidant activity was evaluated by the reducing power, phosphomolybdate tests, and DPPH•, ABTS•+ radical scavenging assays and in the end, the stability of this biosurfactant was studied. objective: Study of the heavy metal biosorption, antioxidant activity, and stability study of lipopeptide biosurfactant BLA 2906 produced by Alcaligenes aquatilis YGD-2906. Results: A negative hemolytic test, emulsion indices of 63.11 % with crude oil, 23.66 mm of oil spreading test, and a positive drop collapse test. The lipopeptide biosurfactant BLA 2906 demonstrated its ability to chelate different heavy metals at pH = 7.2, which gave biosorption capacities of Cu (II), Fe (II), Pb (II), Cd (II), and Zn (II) of 43.34, 43.60, 50.00, 20.08 and 22.48 mg /g of BLA 2906, respectively. The total antioxidant capacity of BLA 2906 presented a value of 0.84 mg Eq Trolox / g DM for the reducing power. On the other hand, the result for the phosphomolybdate test showed a value of 1029.00 ± 3.66 μg / mL to cause a 50 % reduction of the reducing activity of the phosphomolybdenum for the BLA 2906. The result of ABTS+• scavenging activity was 10.46 %. DPPH radical-scavenging effects and BHA at varying concentrations showed that concentrations required to cause 50 % inhibition were 705.48 ± 3.89 μg / ml and 7.61 ± 0.11 μg / ml for this biosurfactant and BHA, respectively. The BLA 2906 showed high stability at different temperatures, pH, and salinity in terms of emulsification activity. Conclusion: The results obtained by the lipopeptide biosurfactant BLA 2906 are attractive to invest in future applications in different fields such as industry, environment and biotechnology.

Shotgun metagenomic analysis of microbiota dynamics during long-term backslopping fermentation of traditional fermented milk in a controlled laboratory environment

Traditional fermented milks are produced through an inoculation process that involves the deliberate introduction of microorganisms that have been adapted and perpetuated across successive generations. However, the changes in the microbiota of traditional fermented milk during long-term inoculation fermentation in a laboratory environment remain unclear. In this study, we collected 5 samples of traditional fermented milk samples from 5 different counties in Tibet (3 kurut products) and Xinjiang (2 tarag products) of China, which served as starter cultures for a 9-mo continuous inoculation fermentation experiment. We analyzed the inter- and intra-population variations in the microbial communities of the collected samples, representing their macrodiversity and microdiversity, using shotgun metagenomic sequencing. Across all samples, we obtained a total of 186 high-quality metagenomic-assembled genomes, including 7 genera and 13 species with a relative abundance of more than 1%. The majority of these genomes were annotated as Lactobacillus helveticus (60.46%), Enterococcus durans (9.52%), and Limosilactobacillus fermentum (6.23%). We observed significant differences in species composition and abundance among the 5 initial inoculants. During the long-term inoculation fermentation, we found an overall increasing trend in species diversity, composition, and abundances of carbohydrate metabolism module-encoding genes in the fermented milk bacterial metagenome, while the fermented milk virome exhibited a relatively narrow range of variation. Lactobacillus helveticus, a dominant species in traditional fermented milk, displayed high stability during the long-term inoculation fermentation. Our study provides valuable insights for the industrial production of traditional fermented milk.

One-step of ionic liquid-assisted stabilization and dispersion: Exfoliated graphene and its applications in stimuli-responsive conductive hydrogels based on chitosan

Conductive hydrogels, as novel flexible biosensors, have demonstrated significant potential in areas such as soft robotics, electronic devices, and wearable technology. Graphene is a promising conductive material, but its dispersibility in aqueous solutions exists difficulties. Here, we discover that untreated graphene, after exfoliation by different ionic liquids, can disperse well in aqueous solutions. We investigate the impact of four ionic liquids with varying alkyl chain lengths ([Bmim]Cl, [Omim]Cl, [Dmim]Cl, [Hmim]Cl) on the dispersibility of grapheme, and a dual physically cross-linked network hydrogel structure is designed using acrylamide (AM), acrylic acid (AA), methyl methacrylate octadecyl ester (SMA), ionic liquid@graphene (ILs@GN), and chitosan (CS). Notably, SMA, CS, AA and AM act as dynamic cross-linking points through hydrophobic interactions and hydrogen bonding, playing a crucial role in energy dissipation. The resulting hydrogel exhibits outstanding stretchability (2250 %), remarkable toughness (1.53 MJ/m3) in tensile deformation performance, high compressive strength (1.13 MPa), rapid electrical responsiveness (response time ∼ 50 ms), high electrical conductivity (12.11 mS/cm), and excellent strain sensing capability (GF = 12.31, strain = 1000 %). These advantages make our composite hydrogel demonstrate high stability in extensive deformations, offering repeatability in pressure and strain and making it a promising candidate for multifunctional sensors and flexible electrodes.

Synthesis of ultrastable silver catalyst supported on alumina nanofibers for carbon monoxide combustion

A catalyst consists of fine aggregates nanoflowers of alumina as support and uniform coating of silver as active component was fabricated to oxidize carbon monoxide. The alumina nanofibers synthesized via a simple electrochemical method. XRD and FE-SEM analysis showed that the thickness of silver deposit was in the range of subnanometer. Elemental mapping also showed a uniform distribution of silver. Also, BET and EDX tests were performed to measure the specific surface area and elemental composition of the catalyst, respectively. Its catalytic activity was measured, and at GHSV equal to 60000 ml/h.g, the end temperature of the oxidizing reaction was 175°C. By increasing the GHSV to 120,000 ml/h.g, the end temperature of the reaction reached 190°C. The thermal stability of the catalyst was also high, as the specific surface area of the catalyst changed from 87m2/g to 51m2/g by increasing the temperature from ambient temperature to 900°C. Due to the high stability of alumina, the structure of the catalyst is always stable. On the other hand, feasibility studies have been given special attention to the advancement of the project. Therefore, for the synthesis of nanocatalyst, available precursors and a simple method have been used, so there will be no problem in the mass production of the catalyst. It is hoped to be able to synthesize nanocatalysts with similar structure and mass production capability for other chemical reactions with this method.

Photocatalytic and fouling resistant MXene/3D-S-COF for efficient oil-water emulsion separation

Three-dimensional sphere covalent organic framework (3D-S-COF) membranes have received increasing attention in the field of oily wastewater and industrial organic matter due to their rich pore structure as well as having many exposed functional group sites. However, the synthesis of conventional imine COF through the Schiff base method, which suffers from the easy hydrolysis under organic solvent conditions. Herein, a novel super-wettable MXene/3D-S-COF composite membrane for oil–water emulsion separation was prepared by depositing MXene nanosheets on oxidized amide COF from the imine COF. The hydroxyl groups of the COF membrane not only improved the water permeability but also formed hydrogen bonds with the MXene layer, which enhanced the interaction and formed the high stability composite membrane. The porous 3D-S-COF and the zigzag MXene layer work synergistically to enable emulsion fluxes up to 240 L·m−2h−1 bar−1 and the separation efficiency is more than 98 %. In addition, the residual mass of the composite membrane remained above 95 % after 10 days of immersion in various solvents, and it also has photocatalytic properties and good resistance to fouling. This study provides a brand new idea for the use of MXene/3D-S-COF based composite membrane for oil–water emulsion separation.

Biochemical Properties of Bioactive Compounds in the Oil from Polish Varieties of Camelina sativa Cultivated in 2019-2022.

Cold-pressed Camelina oil is a traditional oil registered as a traditional food in Poland. Camelina oil has health-promoting properties and high oxidative stability. This may be due to the presence of various bioactive antioxidant compounds such as carotenoids, sterols and polyphenols. Bioactive compounds content in Camelina oil depends mainly on the varieties and on the conditions under which the crop was grown therefore the aim of the research was to analyse antioxidant bioactive compounds in oil from different cultivars of Camelina sativa seeds and to determine their relationship with oil parameters.

Synergistic Machine Learning Accelerated Discovery of Nanoporous Inorganic Crystals as Non-Absorbable Oral Drugs.

Machine learning (ML) has taken drug discovery to new heights, where effective ML training requires vast quantities of high-quality experimental data as input. Non-absorbable oral drugs (NODs) have unique safety advantage for chronic diseases due to their zero systemic exposure, but their empirical discovery is still time-consuming and costly. Here, a synergistic ML method, integrating small data-driven multi-layer unsupervised learning, in silico quantum-mechanical computations, and minimal wet-lab experiments was devised to identify the finest NODs from massive inorganic materials to achieve multi-objective function (high selectivity, large capacity and stability). Based on this method, a NH4-form nanoporous zeolite with MER framework (NH4-MER) was discovered for the treatment of hyperkalemia. In 3 different animal models, NH4-MER showed a superior safety and efficacy profile in reducing blood K+ without Na+ release, which is an unmet clinical need in chronic kidney disease and Gordon's syndrome. Our work provides a synergistic ML method to accelerate the discovery of NODs and other shape-selective materials. This article is protected by copyright. All rights reserved.

Innovative multifunctional nanocapsules with antibacterial, perfume, and UV-initiated coating properties

Polymer nanocapsules containing fragrance were fabricated for antibacterial, pleasing scent and UV-coating applications. Poly (2-methacryloyloxy dodecyl dimethyl ammonium chloride-4-allyloxy-2-hydroxybenzophenone)-block-polymethyl methacrylate-iodide (P(QAC12-BP)-b-PMMA-I) was first synthesized by solution iodine transfer polymerization (solution ITP) for use as a polymerizable surfactant in miniemulsion polymerization where benzalkonium chloride (BKC) was used as a cosurfactant. The nanocapsules were prepared using poly(methyl methacrylate–divinylbenzene) (P(MMA–DVB)) as a shell, whereas mangosteen oil (MO) was used as a fragrance core model for aroma. High colloidal stability nanocapsules with a size of about 213 nm were obtained. The nanocapsule surface contained QAC12 segments of 15.10 µmol/g-capsule (UV measurement), giving the high positive charge (+70 mV). An essential oil encapsulated inside the nanocapsule had a high encapsulation efficiency (>90%). The nanocapsules effectively inhibited bacterial growth because of QAC12 and BKC on their surface. The nanocapsules are able to coat the substrate via UV-activated covalent bonds of the BP segment.

Improvement in crystallization and digestion resistance of debranched amylopectin dextrins using sodium sulfate

In this study, sodium sulfate, a typical kosmotrope salt (100–500 mM), was used to resistant dextrin crystals prepared via enzymatic debranching, and its effects on the crystallization behavior and in vitro digestibility of the dextrin crystals were investigated. Waxy maize starch was enzymatically debranched (50 °C for 24 h) and simultaneously crystallized (50 °C for 2 d) in aqueous solutions containing sodium sulfate (0–500 mM). The yield of dextrin crystals was increased using a sodium sulfate solution (84% at 500 mM sodium sulfate). The dextrin crystals comprise an A-type arrangement of double helices with higher thermal stability than native starch. Based on the DSC, XRD, and in vitro digestibility test, the high thermal stability and crystallinity of the dextrin crystals provide high resistance to digestive enzymes. The addition of sodium sulfate during crystallization increased the crystallinity and thus increased the digestion resistance. According to the in vitro digestibility test, dextrin crystals prepared with 500 mM sodium sulfate contained a resistant fraction of 80.36% in the uncooked state. After cooking (boiling), over half of the dextrin crystals remain resistant to digestive enzymes. This study showed that sodium sulfate, a typical kosmotrope salt, could accelerate the crystallization process of the debranched waxy maize starch chain, increasing yield, thermal stability, crystallinity, and digestion resistance in a short reaction period.

Heat-resistant boron–nitrogen doped lignin-derived adsorbent-catalyst for gaseous aromatic pollutants removal

Lignin-based carbon material can be utilized as carbonaceous adsorbents for the removal of toxic gaseous organic pollutants, while the poor heat-resistance limited its widely application. Here in, B–N co-doped lignin carbon (BN–C) with high thermal stability was synthesized, and the optimized BN-C (1:2) exhibited notably improved heat resistance with the decomposition temperature up to 505 °C, and excellent adsorption capacity for o-dichlorobenzene (o-DCB) (1510.0 mg/g) and toluene (947.3 mg/g), together with good cyclic stability over 10 cycles for o-dichlorobenzene. The existence of abundant hexagonal boron nitride (h-BN) with good thermal conductivity contributed to the superior heat-resistance of BN-C (1:2), and the high specific surface area (1764.5 m2/g), enriched hydroxyl functional groups and improved graphitization degree contributed to its enhanced adsorption performance. More importantly, BN-C (1:2) supported Ru could effectively remove o-DCB and toluene at wide temperature range (50–300 °C). The present work guided the development of heat-resistant lignin-derived adsorbent-catalyst for gaseous aromatic pollutants removal, which benefits both environmental protection and resource utilization.

Study of Serratia phages using virulence tests

One of the main tests in selection of therapeutic phages is studing their virulence. Because of high stability of lysogenic status of bacterial culture, as well as ability in some cases of horizontal transfer of prophages and antibiotic resistance factors, existence of the moderate phages in medical preparations may cause negative results. The Serratia phages were studied with two main tests in the present work: sowing effectiveness and range of lysis action, as well as phage reproductive capacity on the host cells irradiated with UV rays. The results obtained showed that sowing effectiveness of studied phages and range of action are quite high. Out of 14 clones of Serratia phages 11 were characterized with reproductive ability on the host strains inactivated by UV rays. The results of above experimental works and other earlier tests allowed us selecting the components of Serratia phages for the medical-preventive preparation.

Synthesis and Electrocatalytic Performance Study of Sulfur Quantum Dots Modified MoS2.

The electrolysis of water for hydrogen production is currently receiving significant attention due to its advantageous features such as non-toxicity, safety, and environmental friendliness. This is especially crucial considering the urgent need for clean energy. However, the current method of electrolyzing water to produce hydrogen largely relies on expensive metal catalysts, significantly increasing the costs associated with its development. Molybdenum disulfide (MoS2) is considered the most promising alternative to platinum for electrocatalyzing the hydrogen evolution reaction (HER) due to its outstanding catalytic efficiency and robust stability. However, the practical application of this material is hindered by its low conductivity and limited exposure of active sites. MoS2/SQDs composite materials were synthesized using a hydrothermal technique to deposit SQDs onto MoS2. These composite materials were subsequently employed as catalysts for the HER. Research findings indicate that incorporating SQDs can enhance electron transfer rates and increase the active surface area of MoS2, which is crucial for achieving outstanding catalytic performance in the HER. The MoS2/SQDs electrocatalyst exhibits outstanding performance in the HER when tested in a 0.5 M H2SO4 solution. It achieves a remarkably low overpotential of 204 mV and a Tafel slope of 65.82 mV dec-1 at a current density of 10 mA cm-2. Moreover, during continuous operation for 24 h, the initial current density experiences only a 17% reduction, indicating high stability. This study aims to develop an efficient and cost-effective electrocatalyst for water electrolysis. Additionally, it proposes a novel design strategy that uses SQDs as co-catalysts to enhance charge transfer in nanocomposites.

High-accuracy optical vector network analyzer for optical notch and bandpass responses

A high-accuracy optical vector network analyzer (OVNA) based on optical carrier-suppressed double sideband (CS-DSB) modulation is proposed and experimentally demonstrated. The ±1st-order sideband signals are generated by CS-DSB modulation and then pass through the symmetric optical device under test (DUT). The band-stop or band-pass responses can be realized by detecting and processing the double frequency of the driven RF signal. Compared with the conventional symmetrical DSB-based OVNA, the measurement accuracy is improved by eliminating the errors caused by the even-order sidebands, and the complexity is reduced as the proposed method with only one step measurement can avoid the complex postprocessing. In addition, the optical carrier is aligned to the center frequency of the DUT by employing the Pound–Drever–Hall (PDH) technique, which provides stable measurement. At the same time, the limitation that the band-pass responses cannot be measured by the traditional single-sideband (SSB)-based OVNA is overcome. Additionally, accurate magnitude and phase responses of the DUT near the optical carrier can be also achieved since the proposed OVNA is optical filter-immune. The proposed method is theoretically analyzed and verified by experiment. A Fabry–Perot (FP) interferometer serves as the symmetric DUT; the band-stop responses in a frequency range of 6 GHz are obtained with a resolution of 1.2 MHz; and the band-pass responses with the range from 0 to 13 GHz offsetting the optical carrier are also obtained. The measurement time can reach up to 30 min with high stability. The proposed OVNA offers enhanced accuracy and a stable approach for applications in photonic systems and other innovations.

High cycling stability of MnO2 cathode for aqueous Mg-ion batteries enabled by Fe doping

MnO2 has been widely investigated as a promising cathode material for aqueous magnesium-ion batteries, which, however, suffers from the severe capacity fading during charge/discharge cycling. In present work, we report that the doping of Fe in α-MnO2 enlarges the lattice and alleviates the Jahn–Teller distortions and thus accelerates the Mg2+ diffusion and strengthens the structural stability. Consequently, the capacity retention remarkably increases from 44.3 % to 85.2 % after 1000 cycles by Fe doping. Furthermore, it is found for the first time that Fe doping enables the co-insertion of H+ and Mg2+ in the tunnels of α-MnO2, which improves remarkably the specific capacity from 131.9 to 205.9 mA h g−1 at 0.1 A g−1.

Ultrasensitive, Highly Stable, and Stretchable Strain Sensor Using Gated Liquid Metal Channel

AbstractDeveloping stretchable strain sensors with high sensitivity and stability is crucial for various applications such as prosthetic hands, human health monitoring, and human‐machine interactions. However, achieving these qualities simultaneously remains challenging. Here, an inherently stretchable strain sensor is presented that integrates ultrahigh sensitivity and robust stability, enabling stretch, press, or bend sensing capabilities. This sensor employs a softer elastomeric channel filled with liquid metal (LM) as the conductive path. A stiffer elastomer convex integrated into the channel serves as a strain‐manipulated gate, controlling opening gap of electrical current flow path. During deformation, the softer elastomer undergoes cross sectional reduction due to the Poisson effect, while the stiffer convex gate retains its geometry. This heterogeneous deformation behavior leads to significant contraction or closure of the LM channel, resulting in increased resistance and a remarkable enhancement in sensitivity by more than two orders of magnitude. The all‐soft design maintains exceptional stability even under extended or repetitive substantial deformations. With the ability to monitor subtle and large human body movements, detect grip actions of soft grippers reliably, and monitor the gradual and extended growth process of plants, this sensor holds significant potential for advancements in flexible electronics.

Redesigning Solvation Structure toward Passivation-Free Magnesium Metal Batteries.

Simple magnesium (Mg) salt solutions are widely considered as promising electrolytes for next-generation rechargeable Mg metal batteries (RMBs) owing to the direct Mg2+ storage mechanism. However, the passivation layer formed on Mg metal anodes in these electrolytes is considered the key challenge that limits its applicability. Numerous complex halogenide additives have been introduced to etch away the passivation layer, nevertheless, at the expense of the electrolyte's anodic stability and cathodes' cyclability. To overcome this dilemma, here, we design an electrolyte with a weakly coordinated solvation structure which enables passivation-free Mg deposition while maintaining a high anodic stability and cathodic compatibility. In detail, we successfully introduce a hexa-fluoroisopropyloxy (HFIP-) anion into the solvation structure of Mg2+, the weakly [Mg-HFIP]+ contact ion pair facilitates Mg2+ transportation across interfaces. As a consequence, our electrolyte shows outstanding compatibility with the RMBs. The Mg||PDI-EDA and Mg||Mo6S8 full cells use this electrolyte demonstrating a decent capacity retention of ∼80% over 400 cycles and 500 cycles, respectively. This represents a leap in cyclability over simple electrolytes in RMBs while the rest can barely cycle. This work offers an electrolyte system compatible with RMBs and brings deeper understanding of modifying the solvation structure toward practical electrolytes.

A comparative study of alkylammonium halide interface modification for high efficiency and ion migration stability perovskite solar cells

Constructing 2D/3D perovskite heterostructures with organic molecules is key to improving the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). However, a comprehensive understanding of the inhibitory relationship between the 2D perovskite layer and ion migration at the interface is still lacking. In this study, we use different alkyl ammonium iodides to build 2D/3D perovskite heterostructures. The research results show that both the chain length of alkyl and amino group count in alkyl ammonium iodide can significantly affect the crystal structure orientation of the 2D perovskite layer. A Dion-Jacobson (DJ) 2D/3D structure treated with ODADI shows superior defect passivation and carrier extraction, leading to PSCs with a 24.51 % PCE. Furthermore, the perovskite based on ODA cations eliminates the influence of Van der Waals interaction in perovskite based on BA or OA cations, which improves the stability of the lattice structure, and significantly inhibits ion migration. Therefore, after a maximum power point stability test of 1500 h, devices retain approximately 88 % of their initial PCE. This work offers fresh insights into optimizing interfaces in 2D/3D PSCs by selecting suitable organic molecules.

Effect of long-time annealing at high temperature on the microstructure and mechanical properties of different types of SiC fibers

SiC fibers play a crucial role in ceramic-matrix composites due to their excellent high-temperature resistance. To analyze the high temperature stability of different types of SiC fibers, this work investigated three typical SiC fibers (KD-II, KD-S, KD-SA) after being annealed at 1600 °C and 1800 °C for 1 h ∼ 200 h, respectively. For annealing at 1600 °C, the decomposition of the SiCxOy phase and grain growth were the main reasons for strength degradation in KD-II and KD-S fibers, while the KD-SA fiber maintained good thermal stability due to its large grain size. For long-time annealing at 1800 °C, obvious Si sublimation in the three fibers, leading to appearance of skin-core structure, resulted in obvious strength decline. This phenomenon was more pronounced over 1800 °C. These results in this work could be helpful guidance for the preparation of higher performance SiC fibers and SiCf/SiC composites.