Solution Impregnation Research Articles

Response Surface Optimisation of Carbon Dioxide Adsorption Onto Palm Shell Activated Carbon Functionalised With Natural Amino Acids

ABSTRACTAmino acids have shown promising results for carbon dioxide (CO2) capture when functionalised on solid materials; however, the functionalisation often relies on commercial synthetic amino acids. This study investigated the optimal CO2 adsorption performance of amino acid–functionalised material synthesised from palm shell–based activated carbon and natural amino acids, specifically egg white (EW) solution, in a continuous adsorption column. The process conditions of the column were optimised using response surface methodology. Four parameters, namely, the gas flow rate, adsorption temperature, CO2 concentration and EW concentration in the impregnation solution, were identified as significantly affecting CO2 adsorption performance. Good agreements were obtained between the predicted and experimental data, with the coefficients of determination ranging from 0.9639 to 0.9784. A maximum CO2 adsorption capacity of 1.1793 mmol/g was achieved under optimal process conditions: a gas flow rate of 200 mL/min, an adsorption temperature of 25°C, a CO2 concentration of 25 vol.%, and an EW concentration of 15 wt.%. The validation results further confirmed the reliability of the developed model equation in predicting the maximum CO2 adsorption capacity at a fixed 15 vol.% CO2 concentration, with low estimation error. The comparable results obtained using EW waste in this study represent a significant finding in the potential for waste valorisation, aligning with Sustainable Development Goal (SDG) 12 of the United Nations Sustainable Development Goals, as well as contributing to climate action as outlined in SDG 13.

Construction and Properties of Wood-Based Tannin-Iron-Complexed Photothermal Material Populus tomentosa Carr.@Fe-GA for Solar Seawater Desalination System.

Desalinating seawater is a crucial method for addressing the shortage of freshwater resources. High-efficiency, low-cost, and environmentally friendly desalination technologies are key issues that urgently need to be addressed. This work used Populus tomentosa Carr. as a matrix material and prepared Populus tomentosa Carr.@Fe-GA through a complexation reaction to enhance the water evaporation rate and photothermal conversion efficiency of seawater desalination. The concentration of the impregnation solution was further refined, and the bonding mechanism along with the thermal stability of the composite photothermal material was investigated, including an assessment of their photothermal conversion efficiency. The research results indicate that the evaporation rate of water in a 3.5% NaCl solution for Populus tomentosa Carr.@Fe-GA under light intensity conditions of one sun reached 1.72 kg·m-2·h-1, which was an increase of 44.5% compared to untreated Populus tomentosa Carr. It achieved a photothermal conversion efficiency of 95.1%, an improvement of 53.6% over untreated Populus tomentosa Carr., and maintained stability and high evaporation performance (95.4%) even after prolonged rinsing. This work realizes the functional utilization of seawater desalination with Populus tomentosa Carr. and offers a novel approach for the development and use of wood-derived photothermal material.

ECOLOGICAL INNOVATION: THERMOSETTING RESINS AND WATER HYACINTH FIBER IN HIGH-PERFORMANCE BIO-COMPOSITE MATERIALS FOR SUSTAINABLE WASTE MANAGEMENT

<p style="text-align:justify; margin-bottom:11px"><span style="font-size:11pt"><span style="line-height:200%"><span style="font-family:Calibri,"sans-serif""><span lang="EN-US" style="font-size:12.0pt"><span style="line-height:200%"><span style="font-family:"Times New Roman","serif"">Fibrous plants are renewable resources that are abundant in nature. Economically and ecologically, it is especially advantageous to create high-performance composites using inexpensive natural fibres like water hyacinth (Eichhornea crassipes). As a composite matrix, remarkable thermosetting resins like polyester are frequently utilized because polymer composites have excellent dimensional stability, thermal stability, and mechanical qualities. For this investigation, hot curing and solution impregnation procedures were used to create several composites from water hyacinth fibre and polymer. This study's objective is to ascertain how the textures alter when PVC and bio composite components are included. This research is being done to find out what changes polymer materials with fiber-reinforced nanoparticles make. This study uses the water hyacinth (Eichornia crassipers) as a bio-composite material. This type of water hyacinth is usually only seen when the rivers are overflowing. The crystallinity index of water hyacinth fibre composite is 54.82%. The outside of the hyacinth composite is examined under a transmission electron microscope. Hyacinth fibre composite heat degradation is measured using the thermo gravimetric research technique. Additionally the result of this study is to find mechanical, chemical resistance, and morphological properties.</span></span></span></span></span></span></p>

Response surface optimization design of coal-derived activated carbon with high capacitance performance using decreased amount of KOH activated agent

ABSTRACT Coal-derived activated carbon (CAC) is considered as an important direction for high-economic utilization and sustainable development of coal resources. However, this process is limited due to the overall promotion of environmental protection. In this paper, CAC was prepared by H2O activation combined with KOH solution impregnation re-activation of Taixi anthracite. The addition of a small amount of KOH (less than 60 wt% of CACI) significantly promoted the pore formation of CAC, and in addition, a high CAC yield (about 56%) was also obtained. The effects of impregnation conditions of KOH on the specific capacitance of CACII were analyzed by response surface optimization, and the optimal preparation parameters (12.5 mol/L, 82°C and 8.3 h) were obtained. The specific capacitance of CACII prepared under this optimal condition is 334.2 F/g because it has a large specific surface area of 1909.92 m2/g and a defect degree greater than 1. KOH activation improves the wettability of CACII by introducing hydroxy groups. The assembled CACII//CACII symmetrical device also has a higher specific capacitance (224.3 F/g at 0.5 A/g) than the commercial YP-50F. At the same time, it also has a high energy density of 31.15 Wh/kg at 500 W/kg. The physical-chemical multi-stage activation method can significantly reduce the consumption of corrosive chemical reagents in the preparation of CAC, which greatly relieves the pressure of equipment and environment, and lays the foundation for the industrial production of CAC.

Single-Atom Based Metal-Organic Frameworks for Efficient C-S Cross-Coupling.

Single-atom-based Metal-Organic Frameworks (MOFs) hold great promising candidates for heterogeneous catalysis, demonstrating outstanding catalytic activity and exceptional product selectivity. This is attributed to their optimal atom utilization, high surface energy, and the presence of unsaturated coordination environments. Here in, we have developed a nickel single-atom catalyst (SAC) featuring Ni single atoms covalently attached to defect-engineered Zr-oxide clusters within the stable UiO-66 (Universitetet i Oslo) framework, synthesized via a straightforward solution impregnation method (denoted as UiO-66/Ni now onwards). The resulting UiO-66/Ni catalyst, with a uniform distribution of nickel single atoms, exhibits remarkable stability and demonstrates exceptional performance in C-S coupling reactions of various aryl thiols and aryl halides, yielding desired products with outstanding catalytic activity and selectivity, regardless of electron-donating or withdrawing substituents at room temperature and maintains robust stability even after six cycles. Advanced density functional theory calculations have been exploited to clarify the mechanism of C-S cross-coupling for examining the influence of substituents on the aromatic ring of aryl thiols through free energy profiles. The collaborative action of nickel single atoms and the defects of UiO-66 during the oxidative addition and reductive elimination steps facilitated the formation of energetically favorable C-S cross-coupling products. This study offers valuable insights for the development of enhanced single atom-based hybrid catalytic systems for heterogeneous coupling reactions.

Preparation and Characterization of Nanocellulose/Sulfonated Poly(Ether Imide) Composite Membrane and Its Application as Proton Exchange Membrane

ABSTRACTThe TEMPO‐oxidized cellulose nanofibril (CNF) membrane is combined with sulfonated poly(ether imide) (SPEI) using the solution impregnation method to enhance its proton exchange membrane properties. SPEI solutions with different sulfonation levels, SPEI1, SPEI2, SPEI4, and SPEI5, are prepared by adjusting the acetyl sulfate to PEI mole ratios from 1:1 to 2:1, 3:1, 4:1, and 5:1, respectively. The CNF membranes are immersed in each SPEI solution for 24 h and hot‐pressed at 100°C for 1 h to form composite membranes. The chemical structure, morphology, wettability, and membrane characteristics are analyzed. The wettability of SPEI on the CNF surface varies with sulfonation degree, and it affects the morphology of each CNF‐SPEI membrane. Consequently, proton conductivity and ion exchange capacity (IEC) increase, while methanol permeability decreases with increasing sulfonation levels. The CNF‐SPEI5 membrane exhibits the highest proton conductivity of 4.23 mS.cm−1 and the lowest methanol permeability at 6.67 × 10−7 cm2.s−1. Additionally, the CNF‐SPEI4 membrane achieves maximum tensile strength and flexibility at 4.91 ± 0.09 MPa and 15.05% ± 0.24%, respectively. While its proton conductivity still faces challenges, the CNF/SPEI membrane demonstrates better methanol permeability suppression than Nafion 117 (1.31 × 10−6 cm2.s−1) and superior dimensional stability compared with the pristine CNF membrane.

Preparation of an Fe3O4 Nanoparticle/Carbonized Hemp Fiber Composite with Superior Microwave Absorption Performance.

The increasing concern over the negative impact of electromagnetic radiation and interference on humans has led to a growing interest in microwave-absorbing materials that are cost-effective, have a wide frequency range, and have high efficiency. In this paper, an Fe3O4 nanoparticle/carbonized hemp fiber composite was successfully prepared using hemp fibers as the primary material and template. By carefully regulating the concentration of the iron nitrate impregnation solution, accurate loading of Fe3O4 nanoparticles onto the carbonized hemp fiber was achieved. Due to its unique porous structure, the balance between impedance matching, and electromagnetic loss, the prepared Fe3O4 nanoparticle/carbonized hemp fiber composite exhibits light weight, high absorption strength, and broadband absorption characteristics. The broadest absorption bandwidth of 6.1 GHz can be achieved, covering the entire Ku-band, and the minimum refection loss is as low as -49.7 dB. More interestingly, the Fe3O4 nanoparticle/carbonized hemp fiber composite exhibits attractive microwave absorption performance in both the X-band and Ku-band even with a wide range of Fe3O4 nanoparticle loading. Furthermore, simulations of the radar cross section (RCS) have confirmed that the Fe3O4 nanoparticle/carbonized hemp fiber composite is effective in attenuating electromagnetic waves in a real environment. This work presents an economical and efficient method for the development of porous carbon-based absorbents.

Electrochemical Responses of Solution-Impregnated Sulfur/Mesoporous Carbon Composites in Liquid Li-S and Solid-State Li-S Batteries

Lithium sulfur solid-state batteries (Li-S SSBs) have received great attention as next-generation sustainable energy storage devices due to their high energy density, low cost and potential safety. However, start-of-the-art Li SSBs have still faced a few serious of hinders such as distinct high interfacial impedance, insufficient sulfur utilization, lower sulfur mass loading, mismatch triple phase interfaces and also uncertain electrochemical mechanism between liquid and solid-state lithium sulfur batteries. Here, to address these concerns, we employed the encapsulation of sulfur into high conductivemesoporous carbon (MC) by combined solution impregnation and melt-diffusion techniques (IM) to prepare S@MC, and looked into their electrochemical responses in liquid (LiTFSI+LiNO3) and sulfide solid-state (LI6PS5Cl, LPSCl) electrolyte systems. The separately assembled liquid and solid-state Li-S cells exhibited initial discharge capacities of 1438 mAh g-1 and 1411 mAh g-1 at 0.1 C, and capacity retentions of 85.6% (at 0.5 C after 300 cycles) and 48.2% (at 0.5 C after 200 cycles), respectively. In order to enhance the long-term capacity retention of the Li-S SSB prepared by dry mixing of S and LPSCl, we tailored interfaces and introduced ploysulfido-intermediate compounds between S and LPSCl, and thus increasing intimate ionic contact through a weak polar solvent by wet mixing. The solid-state Li-S cells exhibited an initial discharge capacity of 1621 mAh g-1 at 0.1 C with capacity retention of 97.12% (0.1 C initial 5 cycles) and 58.53% (0.5 C after 200 cycles). This work evidently revealed that two step solid-liquid-solid and one step solid-solid charge transfer conversions followed for liquid and sulfide solid state electrolytes, respectively. The solution-impregnated S@MC-2-65%+LPSCl sulfur composite prepared by wet mixing could be potential candidate for high performance Li-S SSBs.

Does the active surface area determine the activity of silica supported nickel catalysts in CO2 methanation reaction?

Two series of silica supported catalysts with comparable nickel contents varying from 2.5 to 20 wt.% were prepared by wet impregnation method in the absence and presence of citric acid in the impregnation solution. Temperature-programmed reduction, X-ray diffraction and electron microscopy studies indicated changes of reducibility of nickel oxide species in the corresponding catalysts and formation of nickel nanoparticles of different size and morphology. A gradual increase in the performance of catalysts in the CO2 methanation reaction was observed with increasing Ni loading. The application of a modified impregnation method led to a reduction in the size of the nickel crystallites, which increased the active surface area of the catalysts, improving their activity and selectivity towards methane at low temperatures, as well as their stability at high temperatures. It was shown that the high active surface area of silica-supported nickel catalysts, due to the presence of small crystallites, is a key factor in increasing their activity. However, other catalyst properties may also play an important role. Hydrogen temperature-programmed desorption and in-situ DRIFTS adsorption/desorption of CO, CO2 and CO2 hydrogenation reaction studies indicated that modification of the method of catalyst synthesis led to changes in the surface properties of the catalysts, affecting the way CO2 and H2 activation and the transformation of resulted intermediate species to the final reaction products.

Chitozan-zeolite Composite Fertilizer Formulations for Enhancing Nutrient Use Efficiency

The experiment was carried out in the Department of Soil Science and Agricultural Chemistry at the College of Agriculture, Vellayani, Kerala, from January to May 2024. Slow release fertilizer formulations (SRF) containing all the major (N, P,K), secondary (Ca, Mg, S) and micronutrients (Zn, B) were prepared using compatible fertilizer materials(urea, diammonium phosphate, muriate of potash, phosphogypsum, magnesium sulphate, zinc sulphate and borax), carrier materials (zeolite and chitosan) which are mixed in five ratios (1:1,1:2,1:3,2:1,3:1) and prepared by two methods namely solid impregnation and solute impregnation. Ten formulations were prepared with different combinations of fertilizer mix, carrier materials and impregnation methods. These formulations were prepared to meet the specific nutrient needs of solanaceous crops (75:40:25 N:P:K kgha-1) and the soil nutrient status. The formulations were characterized for their physical (hygroscopicity, moisture content and stability) and electro-chemical properties (pH, EC) and observed that they are non hygroscopic, non caking and are highly stable. The moisture content of formulations ranged from 2.57 % to 3.92 %, pH 6.30 to 6.81 and EC 10.06 to 16.29 dS m-1. The nutrient content in these formulations were 10.21 to 12.02 % nitrogen, 3.82 to 4.63 % phosphorus, 2.65 to 5.28 % potassium, 5.58 to 6.58 % calcium, 2.46 to 3.08% magnesium, 2.58 to 3.46% sulphur, 1.06 to 1.23% zinc and 0.15 to 0.24% boron. The highest nutrient content was obtained in formulation containing fertilizer mix + C-Z (1:1) prepared by solid impregnation method.

Polylactide Composites Reinforced with Pre-Impregnated Natural Fibre and Continuous Cellulose Yarns for 3D Printing Applications.

Achieving high-performance 3D printing composite filaments requires addressing challenges related to fibre wetting and uniform fibre/polymer distribution. This study evaluates the effectiveness of solution (solvent-based) and emulsion (water-based) impregnation techniques to enhance fibre wetting in bleached flax yarns by polylactide (PLA). For the first time, continuous viscose yarn composites were also produced using both impregnation techniques. All the composites were carefully characterised throughout each stage of production. Initially, single yarns were impregnated and consolidated to optimise formulations and processing parameters. Solution impregnation resulted in the highest tensile strength (356 MPa) for PLA/bleached flax filaments, while emulsion impregnation yielded the highest tensile strength for PLA/viscose filaments (255 MPa) due to better fibre wetting and fibre distribution. Impregnated single yarns were then combined, with additional polymer added to produce filaments compatible with standard material extrusion 3D printers. Despite a reduction in the mechanical performance of the 3D-printed composites due to additional polymer impregnation, relatively high tensile and bending strengths were achieved, and the Charpy impact strength (>127 kJ/m2) for the viscose-based composite exceeded the reported values for bio-derived fibre reinforced composites. The robust mechanical performance of these filaments offers new opportunities for the large-scale additive manufacturing of structural components from bio-derived and renewable resources.

Influencing Factors on the Wet Impregnation of Additive‐Manufactured Catalyst Support Structures

AbstractThe wet impregnation of additive manufactured aluminum oxide cylinders with platinum is investigated. The influence of five parameters on the penetration depth and the platinum loading is evaluated. A smaller penetration depth is obtained by increasing pH, sodium chloride concentration in the impregnation solution, decreasing impregnation solution volume, heating rate during subsequent calcination, and no vacuum during prewetting before the impregnation. A pH range of 2 to 4, a low chloride concentration, a small liquid volume, and no vacuum drawing lead to high platinum uptake. This investigation is crucial in understanding and optimizing the wet impregnation process, providing practical guidance for future research with more complex structures.

Enhancing shelf-life and nutritional value of broccoli florets through vacuum impregnation with calcium chloride and ascorbic acid.

The present investigation aimed to enhance the postharvest shelf-life of broccoli using vacuum impregnation (VI). Broccoli florets were impregnated with physiologically active chemicals, i.e. calcium chloride and ascorbic acid. Post-impregnation broccoli florets were packed in three different packaging materials (poly(ethylene terephthalate) punnets, low-density polyethylene pouches and shrink-wrap film) and stored at two temperatures (5 and 25 °C). The effects of impregnation solutions, packaging materials and storage temperature on physicochemical attributes (weight loss, total soluble solids, ascorbic acid, total chlorophylls and carotenoid content), antioxidant and phenolic contents, and shelf life were studied. The changes in the chemical structure post-impregnation and during storage were investigated using Fourier transform infrared (FTIR) spectroscopy. Results showed that impregnated broccoli florets exhibited significantly (P < 0.05) higher levels of biochemical attributes immediately after impregnation. During storage, the physicochemical and antioxidant properties of broccoli florets declined for all the samples. However, the reduction in these properties was significantly (P < 0.05) lower in impregnated florets as compared to untreated control samples. Principal component analysis and FTIR results also indicated a clear difference in the impregnated and control samples. The shelf-life of broccoli florets stored at 25 °C was assessed as 4 and 3 days for impregnated and control samples, respectively; whereas the samples stored at 5 °C had a shelf-life of 12 days for impregnated samples and 5 days for the control samples. The findings of the study elucidate the potential of VI in enhancing the initial quality and shelf-life of broccoli. The deterioration during storage is primarily due to physiological weight loss, a natural loss of water and volatile compounds that occur following harvest due to transpiration and respiration. Excessive transpiration can lead to dehydration, which reduces the quality and shelf-life of the product. © 2024 Society of Chemical Industry.

Surface Alkali-Modified Nano-CeO2 for Atmospherically Catalytic Polycondensation of CO2 and Diol

The polycondensation of carbon dioxide and diols under atmospheric pressure has significant appeal, thus making the study of catalysts in this process very important. Here, a series of CeO2-X catalysts (X = 9/11/13) with surface modification by basic sites was synthesized via simple impregnation in KOH solution. The structure and morphology of the CeO2-X catalysts remained unchanged after KOH treatment. However, the specific surface area of modified catalysts showed a slight decrease compared with the unmodified samples due to the notable enhancement of basic sites on the surface, resulting in improvement of CO2 adsorption capacity. Furthermore, the catalytic performance of the resultant CeO2-X catalysts was evaluated by solvent-free polymerization of 1,6-hexanediol (HDO) and CO2 at atmospheric pressure (0.1 MPa) using a well-designed reaction apparatus. As a result, the modified catalysts exhibited better performance for CO2 activation due to the existence of abundant basic sites on the surfaces, while CeO2-11 possessed the most favorable catalytic activity and displayed an enhancement of approximately 50% in production compared with that of unmodified CeO2.

Preparation and NH3 adsorption behavior of porous magnesium oxychloride cement-based SrCl2

In addressing challenges in Selective Catalytic Reduction (SCR) systems in vehicles, the development of novel SrCl2 composite materials with high ammonia adsorption and structural stability is crucial. In this context, we employed the porous magnesium oxychloride cement (PMOC) as a carrier material, successfully fabricating a mesoporous PMOC-SrCl2 material via solution impregnation technology. Simultaneously, we employed various characterization techniques such as XRD, full-pore analysis, TG, SEM, TEM, and EDS to examine the material. We conducted static adsorption assessments on numerous candidate materials at 0.1Mpa and 293.15 K. The synthesized C3 series material (Mass ratio of SrCl2 to PMOC = 10:3), solution impregnated for 1 h, exhibited exceptional ammonia adsorption capacity (up to 38.01 mmol·g−1). Through model fitting of experimental data, we discovered that the adsorption process of this material closely aligns with the pseudo-second-order kinetic model and the Langmuir model. Over an adsorption time span of 180 min, the adsorption rate of the composite material increased by 129 % compared to pure SrCl2. In the cycle performance testing phase, we observed that the material exhibited no significant degradation in performance after undergoing 10 cycles of adsorption/desorption. This structurally stable, cost-effective, and readily accessible high-efficiency ammonia adsorption material undoubtedly possesses immense potential to solve the application challenges of ammonia adsorption materials within automotive selective catalytic reduction systems.

Facile and Environmentally Friendly Synthesis of Ga2O3/MFI Catalysts for Propane Dehydrogenation.

A GaOx-based catalyst is recognized as a promising catalyst for dehydrogenation of light alkanes. Conventionally, impregnation and calcination are necessary processes for the loading of GaOx. However, the incomplete impregnation of gallium salt solution would generate wastewater, and the calcination for the dissociation of gallium salt would release harmful gases, such as SOx, NOx, and HCl. Meanwhile, the high temperature results in an excessive energy cost and undesired GaOx particle aggregation. Here, we report a facile and environmentally friendly method for the synthesis of GaOx-based catalysts. The gallium salt solution was replaced directly with liquid gallium (LG). Through a simple physical mixing method at room temperature, uniform GaOx nanoparticles with diameters of around 3.5 nm were loaded onto the surface of silicalite-1 (S-1). With the optimal GaOx/MFI catalyst, the propane conversion and propylene selectivity reached 22.9 and 90.1%, respectively, in the propane dehydrogenation reaction. The work offers a clean and economical strategy utilizing liquid metal (LM) as an impregnation solution for the preparation of GaOx-based catalysts.

On the physical-mechanical and tribotechnical properties of antifriction carbon fiber based on a modified thermosetting matrix

The physical-mechanical and tribological properties of anti-friction carbon fiber plastic UGET based on low-modulus carbon fabric “Ural T-15R” have been studied in order to increase the magnitude of the ultimate deformation and reduce the elastic modulus through the use of a modified thermosetting matrix ET-4 instead of the traditionally used ET-2.Modes of polymerization and of heat treatment of epoxy binders were selected considering the results of the experiments. Prototypes of prepregs were obtained by solution impregnation on the UPST-1000M line and then processed into PCM by hot pressing. Laboratory samples were made and physical and mechanical tests were carried out to determine the ultimate strength under compression, shear and bending stress under destruction, as well as Charpy impact strength. Steel 20Kh13 and oxidized titanium alloy PT-3V were used as counter body rollers to determine carbon fiber tribosets.It was shown that carbon fiber samples based on chemically modified binder ET-4 with two-stage polymerization and heat treatment mode in the range of 90°C to 180°C both have better physical-mechanical and tribotechnical properties, in contrast with the analogue with a three-stage mode and carbon fiber carbon heat at friction over 20Kh13 steel and oxidized titanium alloy PT-3V.

Aramid nanofiber-modified carbon paper to enhance adaptability and performance of proton exchange membrane fuel cells

This study developed a novel method to enhance the comprehensive performance of carbon paper (CP) by using aramid nanofibers (ANF) modified phenol formaldehyde resin (PF). The effect of ANF modification ratios (0 wt%, 0.6 wt%, 1.2 wt%, 1.8 wt%, 2.4 wt%) on ANF dispersion in PF impregnation solution, PF thermal stability, and PF carbon matrix structure were investigated. Compared to unmodified PF, ANF-modified PF matrix carbon exhibited increasingly regular and ordered structures, with the ID/IG value decreasing from 2.16 to 2.02. Furthermore, with ANF modification ratio increasing, the tensile strength, flexural strength, porosity and gas permeability of CP exhibited a pattern of initial increase followed by a decrease, and when increasing to 1.8 %, reaching the optimal values of 14.28 MPa, 531.61 MPa, 85.94 %, and 2520 L·m−2·s−1, respectively. The limiting power density of proton exchange membrane fuel cells (PEMFCs) assembled with 1.8 wt% ANF-modified CP gradually increased with different assembly torques of 2, 4 and 6 N·m, reaching maximum values of 0.86, 0.98, and 1.1 W·cm−2, respectively. Therefore, the novel ANF modification method of CP provides new insights into enhancing PEMFCs assembly adaptability, potentially addressing issues related to low mechanical stability and poor pore structure affecting PEMFCs performance.

Vascular Graft Impregnation with a Fosfomycin/Oritavancin Combination to Prevent Early Infection.

Background/Objectives: Vascular graft infections (VGIs) represent a life-threatening complication, occurring in 0.2-6% of patients following aortic prosthetic placements. Historically, the primary focus for reducing VGIs has been on prevention. Currently, antimicrobial grafts are not available on the market. This study aimed to evaluate the efficacy of combining two antibiotics, fosfomycin and oritavancin, impregnated into the commercially available GelweaveTM vascular graft as a prophylactic alternative against the most commonly implicated bacteria responsible for VGI. Methods: The antimicrobial activity of fosfomycin and oritavancin was assessed using the broth microdilution method, and a synergistic effect was demonstrated using the checkerboard assay against Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococcus faecium. The antibiotics were impregnated into the commercial vascular graft through immersion, and the antimicrobial efficacy of the fosfomycin/oritavancin-impregnated graft was assessed over a period of 7 days. Results: Eradication of all microorganisms tested was achieved using impregnation solutions with concentrations of 40 mg/mL of fosfomycin and 256 µg/mL of oritavancin. Conclusions: Impregnation with the combination of fosfomycin/oritavancin proved to be a promising approach to prevent VGIs. Vascular grafts with impregnated antibiotics are not yet available on the market, and this work represents an important step toward the development of a new class of antimicrobial vascular grafts.

NiCo2S4 nanoparticles encapsulated within hollow mesoporous carbon spheres enabling rapid and stable sodium storage

Poor rate capability and cycling performance significantly impair the utilization of NiCo2S4 as an anode material in sodium-ion batteries. Herein, hollow mesoporous carbon spheres (HMCSs) are synthesized using a hard-template method. NiCo2S4 nanoparticles with sizes ranging from 15 to 43 nm are grown in-situ within HMCSs (NiCo2S4@HMCS) by melt adsorption, solution impregnation, and gas-phase sulfurization. Specifically, NiCo2S4 nanoparticles are uniformly distributed on the inner walls of HMCSs and within the mesoporous channels of spherical shells. In half-cells, NiCo2S4@HMCS exhibits reversible capacities of 482 mAh g−1 after 340 cycles at 1.0 A g−1, 340 mAh g−1 after 600 cycles at 5.0 A g−1, and 271 mAh g−1 after 700 cycles at 10.0 A g−1. In NiCo2S4@HMCS//Na3V2(PO4)3 full-cells, NiCo2S4@HMCS maintain reversible capacities of 203 mAh g−1 after 1200 cycles at 1.0 A g−1 and 122 mAh g−1 after 2000 cycles at 5.0 A g−1. The unique nano-encapsulated structure prevents the detachment of NiCo2S4 from HMCSs, maintaining electrochemical activity and stability of NiCo2S4. Additionally, the nano-encapsulated structure also facilitates electrolyte penetration and enhances the electronic conductivity of NiCo2S4. These effects synergistically result in rapid and stable sodium storage performance.