Transport Capability Research Articles

Determining the Permeability of Porous Bioceramic Scaffolds: Significance, Overview of Current Methods and Challenges Ahead

The “architectural suitability” of scaffolds for bone tissue engineering is commonly evaluated by assessing the pore volume and the mean pore size (or pore size distribution, if possible) and comparing these values with the reference ranges of human cancellous bone. However, these two parameters cannot precisely describe the complex architecture of bone scaffolds and just provide a preliminary comparative criterion. Permeability is suggested as a more comprehensive and significant parameter to characterize scaffold architecture and mass transport capability, being also related to bone in-growth and, thus, functional properties. However, assessing the permeability of bioactive ceramics and glass scaffolds is a complex task from both methodological and experimental viewpoints. After providing an overview of the fundamentals about porosity in scaffolds, this review explores the different experimental and numerical approaches used to determine the permeability of porous bioceramics, describing the methodologies used (pump-based, gravity-based, acoustic and computational methods) and highlighting advantages and limitations to overcome (e.g., reliability issues and need for better standardization of the experimental procedures).

Modular Assembly of Photoactive Lipid Nanoparticles on Red Blood Cells toward Enhanced Phototherapy Efficacy.

Photodynamic therapy has been developed as a promising treatment for malignant tumors, which inspires research into photosensitizers. However, the therapeutic efficacy of individual photosensitizers is often hampered by the physiological environment. The assembly of biological materials with synthetic molecules offers a strategy to enhance functionality while improving tolerance to varying physiological conditions. Herein, we present a biohybrid system for enhanced phototherapy efficacy through a simple two-step assembly process. Photoactive lipid nanoparticles were assembled based on synthesized conjugated molecules and lipophilic prodrugs, which were then modularly assembled with red blood cells (RBCs). Driven by hydrophobic and electrostatic interactions, hydrophobic conjugated molecules were efficiently incorporated into the RBCs, while lipophilic prodrugs were simultaneously inserted into the cell membranes. The engineered RBCs harnessed the natural oxygen transport capability, enabling the internal conjugated molecules to effectively produce reactive oxygen species (ROSs) even under oxygen-poor conditions. Meanwhile, the use of ROS-cleavable linkers in prodrugs enhanced drug release for chemotherapy, which is a perfect complement to photodynamic therapy. In vitro and in vivo experiments proved the improved phototherapy efficacy of the biohybrid system. Furthermore, the changes in aggregation directed Förster resonance energy transfer between conjugated molecules and fluorescent drugs provided a mechanism to track drug release from engineered RBCs. Therefore, the modular assembly of biohybrid systems can offer multiple functionalities required for phototherapy, on-demand drug release, and imaging.

Influence of CuO nanoparticles on photosystem II structural stability and functional activity of corn (Zea mays L.) under drought stress

Photoinhibition and photooxidation of photosystem II (PSII) is one of the key damages caused by drought stress. The present study aimed to assess whether or not foliar application of copper oxide nanoparticles (CuO NPs) is effective in promoting PSII stability and activity in corn plants under drought stress. Three-week old plants of corn were subjected to drought stress and varying levels of CuO nano-particles (0, 25, 50, and 100 mM) of the rooting medium. In this study, the effects of foliar application of copper oxide nanoparticles were assessed on growth, plant water status, nutrient uptake and structural stability of photosystem II of drought stressed corn plants. Drought stress impeded overall growth of the corn plants by reducing leaf relative water content, water potential, chlorophyll a content, and accumulation of K+ in plant leaves and roots. Exogenous application of 25 mM CuO NPs significantly enhanced the growth of corn. Exogenous application of CuO NPs improved the dry biomass and length of roots of the corn plants under drought stress. Although the application of nano-particles did not change leaf photosynthetic pigments, relative water content, K+ accumulation, it enhanced the accumulation of K+ in roots. Drought stress did not affect the structural stability of PSII, but it reduced its activity (performance index, PIABS) due to changes in the reaction center density and the biochemical reaction efficiency or electron transport capability. Exogenous application of CuO NPs improved PIABS due to increase in active reaction center density and electron transport efficiency. However, 100 mM CuO NPs application caused PSII damage at the donor end and reduced active reaction center density in the corn plants under both normal and drought stress conditions. The present findings provide a baseline information that foliar application of CuO-nanoparticles in low concentrations can improve the growth of corn by improving accumulation of K+ and increasing PSII activity. Further research is required to explore its effect on cellular redox balance and activities of PSII and PSI, and optimum dose of CuO-nanoparticles for developing formulations for their commercial applications in farmers’ fields.

Perovskite Thin-Film Transistors for Ultra-Low-Voltage Neuromorphic Visions.

Perovskite thin-film transistors (TFTs) simultaneously possessing exceptional carrier transport capabilities, nonvolatile memory effects, and photosensitivity have recently attracted attention in fields of both complementary circuits and neuromorphic computing. Despite continuous performance improvements through additive and composition engineering of the channel materials, the equally crucial dielectric/channel interfaces of perovskite TFTs have remained underexplored. Here, it is demonstrated that engineering the dielectric/channel interface in 2D tin perovskite TFTs not only enhances the performance and operational stability for their utilization in complementary circuits but also enables efficient synaptic behaviors (optical information sensing and storage) under an extremely low operating voltage of -1mV at the same time. The interface-engineered TFT arrays operating at -1mV are then demonstrated as the preprocessing hardware for neuromorphic visions with pattern recognition accuracy of 92.2% and long-term memory capability. Such a low operating voltage provides operational feasibility to the design of large-scale-integrated and wearable/implantable neuromorphic hardware.

Thermoelectric properties of XX- and XY-stacked GeS/GeSe van der Waals heterostructures from DFT and BTP calculations.

This study utilizes density functional theory (DFT) and the Boltzmann transport equation (BTE) to investigate the structural, electronic, and thermoelectric properties of germanium sulfide (GeS) and germanium selenide (GeSe) monolayers, along with their van der Waals (vdW) heterostructures. We analyzed XX-stacked and XY-stacked configurations, where the XX configuration features direct atomic stacking, while the XY configuration exhibits staggered stacking. Our first-principles calculations indicate that the formation of GeS/GeSe heterostructures results in a reduction of bandgaps compared to their bulk and monolayer counterparts, yielding bandgap values of 0.91 eV for the XX configuration and 0.84 eV for the XY configuration. Stability assessments reveal that the XY configuration is more stable, demonstrating a lattice thermal conductivity of 15.21 W/mK compared to 17.95 W/mK for the XX configuration T 300 K. The thermoelectric properties were systematically evaluated across a temperature range of 300-800 K, revealing high Seebeck coefficients of 1.51 mV/K for the XX heterostructure and 1.39 mV/K for the XY heterostructure. reflecting their excellent charge transport capabilities. Notably, the figure of merit (ZT) at 800 K was calculated to be 0.90 for the XX configuration and 1.01 for the XY configuration, underscoring the superior thermoelectric performance of the XY heterostructure. These findings contribute to a comprehensive understanding of 2D GeS/GeSe heterostructures for thermoelectric applications and provide a solid foundation for future research and technological advancements in this domain.

Activity Control of a Synthetic Transporter by Photodynamic Modulation of Membrane Mobility and Incorporation.

Artificial transmembrane transport systems are receiving a great deal of attention for their potential therapeutic application. A major challenge is to switch their activity in response to environmental stimuli, which has been achieved mostly by modulating the binding affinity. We demonstrate here that the activity of a synthetic anion transporter can be controlled through changes in the membrane mobility and incorporation. The transporters─equipped with azobenzene photoswitches─poorly incorporate into the bilayer membrane as their thermally stable (E,E,E)-isomers, but incorporation is triggered by UV irradiation to give the (Z)-containing isomers. The latter isomers, however, are found to have a lower mobility and are therefore the least active transporters. This opposite effect of E-Z isomerization on transport capability offers unique photocontrol as is demonstrated by in situ irradiation studies during the used transport assays. These results help to understand the behavior of artificial transporters in a bilayer and are highly important to future designs, with new modes of biological activity and with the possibility to direct motion, which may be crucial toward achieving active transport.

Robust Control of Chat-PM: A Switched Singular System with Mode-dependent Bounded Nonlinearity

This paper is concerned with the robust control of the composite hybrid aerial-terrestrial precise manipulator (Chat-PM), a quadrotor-based robot with aerial/terrestrial movement and payload transportation capabilities. Given the distinct dynamics between aerial and terrestrial locomotion modes, Chat-PM is modeled as a type of switched singular system. A nonlinear term is contained in the system to model the coupling between translational and rotational movements of Chat-PM, which is proven to be norm-bounded and mode-dependent. Besides, the estimation error of the robotic arm's interaction force/torque is treated as the disturbance of the system. By means of the mixed H2/H∞ approach, numerically testable stability criterion are obtained, based on which the existence conditions for controllers with satisfactory transient and disturbance attenuation performance are provided. Compared to traditional studies assuming the nonlinearity term to be mode-independent, the conservatism in the controller design is reduced. Experimental results are provided to demonstrate the effectiveness of the proposed approach.

Natural Polyphenol‐Reinforced Ion‐Selective Separators for High‐Performance Lithium‐Sulfur Batteries with High Sulfur Loading and Lean Electrolyte

Ion‐selective separators are promising to inhibit soluble intermediates shuttle in practical lithium‐sulfur (Li‐S) batteries. However, designing and fabricating such high‐performance ion‐selective separators using cost‐effective, eco‐friendly, and versatile methods remains a formidable challenge. Here we present ion‐selective separators fabricated via the spontaneous deposition of green tea‐derived polyphenols onto a polypropylene separator, aimed at enhancing the stability of Li‐S batteries. The resulting natural polyphenol‐reinforced ion‐selective (NPRIS24) separators exhibit rapid Li ion transport and high soluble intermediates inhibition capability with an ultralow shuttle rate of 0.67% for Li2S4, 0.19% for Li2S6 and 0.10% for Li2S8. This superior ion‐selectivity arises from the high electronegativity and strong lithiophilic nature of the phenolic compounds. Consequently, we have achieved high‐performance Li‐S batteries that are steadily cyclable under the challenging conditions of an S loading of 5.7 mg cm−2, an electrolyte‐to‐S ratio of 5.1 μL mg−1, and a 50 μm Li foil anode. Furthermore, the NPRIS24 separator enhances the performance of other Li metal batteries utilizing commercial LiFePO4 (5.3 mg cm−2) and LiNi0.5Co0.2Mn0.3O2 (9.9 mg cm−2) cathodes. This work underscores the potential of utilizing natural polyphenols for the design of advanced ion‐selective separators in energy storage systems.

Natural Polyphenol-Reinforced Ion-Selective Separators for High-Performance Lithium-Sulfur Batteries with High Sulfur Loading and Lean Electrolyte.

Ion-selective separators are promising to inhibit soluble intermediates shuttle in practical lithium-sulfur (Li-S) batteries. However, designing and fabricating such high-performance ion-selective separators using cost-effective, eco-friendly, and versatile methods remains a formidable challenge. Here we present ion-selective separators fabricated via the spontaneous deposition of green tea-derived polyphenols onto a polypropylene separator, aimed at enhancing the stability of Li-S batteries. The resulting natural polyphenol-reinforced ion-selective (NPRIS24) separators exhibit rapid Li ion transport and high soluble intermediates inhibition capability with an ultralow shuttle rate of 0.67% for Li2S4, 0.19% for Li2S6 and 0.10% for Li2S8. This superior ion-selectivity arises from the high electronegativity and strong lithiophilic nature of the phenolic compounds. Consequently, we have achieved high-performance Li-S batteries that are steadily cyclable under the challenging conditions of an S loading of 5.7 mg cm-2, an electrolyte-to-S ratio of 5.1 μL mg-1, and a 50 μm Li foil anode. Furthermore, the NPRIS24 separator enhances the performance of other Li metal batteries utilizing commercial LiFePO4 (5.3 mg cm-2) and LiNi0.5Co0.2Mn0.3O2 (9.9 mg cm-2) cathodes. This work underscores the potential of utilizing natural polyphenols for the design of advanced ion-selective separators in energy storage systems.

Exploring circulation dynamics in Han Dynasty China: insights from isotopic analysis of lead glazed pottery

This study investigates lead provenance and circulation patterns in Han Dynasty (202BC-220AD) China through the analysis of lead glazed pottery. Four objects were studied using a combination of typological study, elemental chemistry and lead isotope ratio analysis. The results for each object were compared with databases of ‘lead mining districts’ (lead deposits) and ‘lead usage districts’ (lead-containing artifacts unearthed in different spatial and temporal ranges) to assess the lead sources used for each sample and offers a spatial-temporal range of the use of these lead resources. Three distinct groups of lead and their possible circulating spatial-temporal scales are identified across six samples in this study. A possible change in lead supply networks between the Western Han Dynasty (202BC-9AD) and the Eastern Han Dynasty (25AD-220AD) is proposed. This study also highlights the probable changes in the movement of lead resources from the Western Han Dynasty to the Tang Dynasty (618AD-690AD), suggesting improvements in long-distance transport capabilities, and the development of economic divisions and exchange connections in ancient Chinese society. Our findings contribute to a deeper understanding of the economic and political dynamics during the Han Dynasty and emphasize the significance of lead isotope analysis of glazed pottery in exploring resource movement.

Cryogels Composites: Recent Improvement in Bone Tissue Engineering.

Autogenous bone grafts have long been considered the optimal choice for bone reconstruction due to their excellent biocompatibility and osteogenic properties. However, their limited availability and associated donor site morbidity have led to exploration of alternative bone substitutes. Cryogels, with their interconnected porosity, shape recovery, and enhanced mass transport capabilities, have emerged as a promising polymer-based solution. By incorporating bioactive glasses and nanofillers, cryogel composites offer bioactivity, cost-efficiency, and easy cell integration. This approach not only enhances bone regeneration but also underscores the broader role of nanotechnology in regenerative medicine. This mini-review discusses the advancement of organic-inorganic composites, focusing on biopolymeric cryogels and inorganic elements for reinforcement. We highlight how cryogels can be integrated into minimally invasive procedures, reducing patient distress and complications, and advanced 3D-printing techniques that enable further customization of these materials to mimic bone tissue architecture, offering potential for patient-specific treatments.

Horizontal Transport in Ti3C2Tx MXene for Highly Efficient Osmotic Energy Conversion from Saline‐Alkali Environments

AbstractOsmotic energy from the ocean has been thoroughly studied, but that from saline‐alkali lakes is constrained by the ion‐exchange membranes due to the trade‐off between permeability and selectivity, stemming from the unfavorable structure of nanoconfined channels, pH tolerance, and chemical stability of the membranes. Inspired by the rapid water transport in xylem conduit structures, we propose a horizontal transport MXene (H‐MXene) with ionic sequential transport nanochannels, designed to endure extreme saline‐alkali conditions while enhancing ion selectivity and permeability. The H‐MXene demonstrates superior ion conductivity of 20.67 S m−1 in 1 M NaCl solution and a diffusion current density of 308 A m−2 at a 10‐fold salinity gradient of NaCl solution, significantly outperforming the conventional vertical transport MXene (V‐MXene). Both experimental and simulation studies have confirmed that H‐MXene represents a novel approach to circumventing the permeability‐selectivity trade‐off. Moreover, it exhibits efficient ion transport capabilities, addressing the gap in saline‐alkali osmotic power generation.

Horizontal Transport in Ti3C2Tx MXene for Highly Efficient Osmotic Energy Conversion from Saline-Alkali Environments.

Osmotic energy from the ocean has been thoroughly studied, but that from saline-alkali lakes is constrained by the ion-exchange membranes due to the trade-off between permeability and selectivity, stemming from the unfavorable structure of nanoconfined channels, pH tolerance, and chemical stability of the membranes. Inspired by the rapid water transport in xylem conduit structures, we propose a horizontal transport MXene (H-MXene) with ionic sequential transport nanochannels, designed to endure extreme saline-alkali conditions while enhancing ion selectivity and permeability. The H-MXene demonstrates superior ion conductivity of 20.67 S m-1 in 1 M NaCl solution and a diffusion current density of 308 A m-2 at a 10-fold salinity gradient of NaCl solution, significantly outperforming the conventional vertical transport MXene (V-MXene). Both experimental and simulation studies have confirmed that H-MXene represents a novel approach to circumventing the permeability-selectivity trade-off. Moreover, it exhibits efficient ion transport capabilities, addressing the gap in saline-alkali osmotic power generation.

3D-printed modular platform for path-customizable liquids transport

Spontaneous liquid transport is increasingly being applied in various fields such as microfluidics, fuel cells, phase change heat transfer, water harvesting, etc. However, long-distance spontaneous liquid transport with path-customizable motion trajectories is still challenging. Drawing multi-inspirations from the wedge-shaped structures of iris petals, the continuous structures of bamboo joints, and the microgroove structures of Nepenthes mouth edge, we fabricate a modular, pump-free biomimetic liquid transport platform by 3D printing and surface modification. The platform is composed of sequential wedge notches, and a crescent-shaped groove is designed at the joint of every two connected wedge structures. The platform is characterized by path-customizable liquid transport trajectories and can be used to achieve long-distance liquid transport without the need of external energy fields, and the multi-level nested structures along the depth significantly facilitates the liquid transport. Experimental study and theoretical force analysis show that the crescent-shaped grooves enable the liquid to overcome joint barriers by converting potential energy accumulated at joints into kinetic energy, achieving a maximum velocity of 18 mm/s. Taking advantage of the flexibility of 3D printing and long-distance transport capability, the modular structure of the platform enables customization of the transport distance and trajectory. By assembling 14 bamboo-like wedge-shaped units in series, we realized a transport distance up to 350 mm, which could be further increased by connecting more units. Furthermore, we develop various modular and multifunctional liquid transport platforms for anti-gravity transport, liquid diversion, and customized transport trajectories, which demonstrate that our design strategy could be an available solution for path-customizable liquids transport in fields like bio-sensing, fuel cells, etc.

Enhancing Conductivity of Nickel Oxide to Achieve Scalable Preparation for High-Efficiency Perovskite Solar Modules

NiOx, prepared via the sputtering method, exhibits low conductivity and energy level mismatch with the perovskite layer, thereby limiting further enhancements in the performance of perovskite solar modules (PSMs). Unlike traditional methods that enhance the performance of NiOx through reactive sputtering or directly doping NiOx targets with metal ions, both of which incur high costs and low efficiency, we employ an evaporation method using LiF to achieve efficient and low-cost doping of NiOx. Compared to the pristine NiOx, the incorporation of LiF significantly increases the conductivity of NiOx. Additionally, the incorporation of LiF enhances the quality of the deposited perovskite films, as well as the energy level alignment and symmetry between NiOx and the perovskite, effectively improving the hole extraction and transport capabilities between NiOx and the perovskite. As a result, the PSM (active area of 57.30 cm²) fabricated in air achieves an impressive efficiency of 19.54%. Furthermore, the unencapsulated PSM retains 80% of its initial efficiency after 700 h of continuous illumination, whereas the NiOx-based PSM drops to 80% after only 150 h. This study provides a simple and low-cost method for doping NiOx, which is of great significance for the further industrialization of PSMs.

IPSC-derived blood-brain barrier modeling reveals APOE isoform-dependent interactions with amyloid beta

BackgroundThree common isoforms of the apolipoprotein E (APOE) gene - APOE2, APOE3, and APOE4 - hold varying significance in Alzheimer’s Disease (AD) risk. The APOE4 allele is the strongest known genetic risk factor for late-onset Alzheimer’s Disease (AD), and its expression has been shown to correlate with increased central nervous system (CNS) amyloid deposition and accelerated neurodegeneration. Conversely, APOE2 is associated with reduced AD risk and lower CNS amyloid burden. Recent clinical data have suggested that increased blood-brain barrier (BBB) leakage is commonly observed among AD patients and APOE4 carriers. However, it remains unclear how different APOE isoforms may impact AD-related pathologies at the BBB.MethodsTo explore potential impacts of APOE genotypes on BBB properties and BBB interactions with amyloid beta, we differentiated isogenic human induced pluripotent stem cell (iPSC) lines with different APOE genotypes into both brain microvascular endothelial cell-like cells (BMEC-like cells) and brain pericyte-like cells. We then compared the effect of different APOE isoforms on BBB-related and AD-related phenotypes. Statistical significance was determined via ANOVA with Tukey’s post hoc testing as appropriate.ResultsIsogenic BMEC-like cells with different APOE genotypes had similar trans-endothelial electrical resistance, tight junction integrity and efflux transporter gene expression. However, recombinant APOE4 protein significantly impeded the “brain-to-blood” amyloid beta 1–40 (Aβ40) transport capabilities of BMEC-like cells, suggesting a role in diminished amyloid clearance. Conversely, APOE2 increased amyloid beta 1–42 (Aβ42) transport in the model. Furthermore, we demonstrated that APOE-mediated amyloid transport by BMEC-like cells is dependent on LRP1 and p-glycoprotein pathways, mirroring in vivo findings. Pericyte-like cells exhibited similar APOE secretion levels across genotypes, yet APOE4 pericyte-like cells showed heightened extracellular amyloid deposition, while APOE2 pericyte-like cells displayed the least amyloid deposition, an observation in line with vascular pathologies in AD patients.ConclusionsWhile APOE genotype did not directly impact general BMEC or pericyte properties, APOE4 exacerbated amyloid clearance and deposition at the model BBB. Conversely, APOE2 demonstrated a potentially protective role by increasing amyloid transport and decreasing deposition. Our findings highlight that iPSC-derived BBB models can potentially capture amyloid pathologies at the BBB, motivating further development of such in vitro models in AD modeling and drug development.

Investigations on the complexation and binding mechanism of bovine serum albumin with Ag-doped TiO2 nanoparticles.

It is essential to study the interactions between nanoparticles and proteins to better understand the biological interactions of nanoparticles. In this study, we studied the protein adsorption mode on the surface of Ag-doped TiO2 nanoparticles (NPs) using a model protein, bovine serum albumin (BSA). The mechanism of binding BSA to the Ag-doped TiO2 NPs was studied by applying fluorescence quenching, absorbance measurements, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy techniques. The strong binding between BSA and Ag-doped TiO2 NPs was confirmed by a high value of binding constant (K = 2.65 × 105 L mol-1). We also studied the thermal stability of BSA in the presence of the Ag-doped TiO2 NPs. Thermodynamic parameters indicated that the adsorption of BSA on the Ag-doped TiO2 NPs was a spontaneous, natural and exothermic process. The effect of Ag-doped TiO2 NPs on the transportation function of BSA was also studied using a fluorescence spectroscopic technique. Fluorescence spectroscopic data suggested the existence of a strong interaction between BSA and the surface of the Ag-doped TiO2 NPs, which indicated that the binding affinities of some selected amino acids in BSA changed. This, in turn, clearly confirms that the Ag-doped TiO2 NPs affect the transportation capability of BSA in blood.

Novel fracturing fluid made of low molecular weight polymer and surfactant achieves proppant full suspension and filling entire area of hydraulic fractures

In large-scale hydraulic fracturing of unconventional reservoirs, high viscosity friction reducers (HVFR) which employ high concentration polymers of high molecular weight can improve proppant suspension, but still lack long-distance and long-time proppant transport capability. Herein, for the first time, we report a fracturing fluid made of self- assembled low molecular weight polymer and a surfactant (LMPS). When using only 0.1 wt% of the polymer, LMPS has a viscosity of 29.6 mPa·s (170 s−1, 25 ℃) and can achieve full suspension of 40/70 mesh sand at 80 ℃. LMPS can form robust short molecular chain networks through numerous self-assembling association sites, rather than relying on entanglement. Notably, it achieves a minimum loss tangent as low as 0.1 in the viscoelastic response, demonstrating its strong elastic characteristics. According to the creep-recovery test, the strain recovery rate (87.9 %) of LMPS at 0.2 wt% polymer concentration far exceeds that of the HVFR with a concentration as high as 10.1 %. This indicates that LMPS has a stronger deformation-resisting ability, thereby preventing proppant settling. Taking advantage of LMPS’ superior proppant suspension capability, proppant can move with the slurry to the whole fracture for placement, while the HVFR provides only 48 % height support of the fractures in the form of dunes. A field trial shows that at a polymer concentration of 0.2 wt%, LMPS can stably transport 20/40 mesh quartz sand under a slurry rate of 2.8 m3/min and a proppant concentration of 635 kg/m3 during the fracturing process.

Tough, antimicrobial, recyclable hydrogel with tree-trunk-inspired core‐sheath structure for efficient all-day desalination

Solar-driven interfacial evaporation, an economically friendly freshwater harvesting technology, faces the challenge of achieving efficient all-day desalination. Inspired by the core‐sheath structure of tree trunks, herein, a hydrogel evaporator features internal vertical lamellar sodium alginate (SA) pores supported by aramid fiber (AF) networks and surface covered with a dense layer of copper sulfide (CuS) and was fabricated through freeze-drying-cycling alternating immersion method. The internal vertical SA lamellar structure endows the hydrogel with strong water transport capability, while the high photothermal conversion ability of the surface CuS layer enables rapid water evaporation. Therefore, as 2D evaporators, the evaporation rate in highly concentrated salt solutions (15 wt%) is up to 2.07 kg m-2 h-1 under 1.0 sun. As 3D evaporators, efficient evaporation is achieved throughout the day by compensating evaporation at the sides and top. Under the irradiation of 0.2 and 0.8 suns outdoors, the evaporation rate of the 3D evaporator can reach 7.47 kg m-2 h-1 and 12.60 kg m-2 h-1, respectively, and its total evaporation is 4.72 times higher than that of the 2D evaporator. Notably, the hydrogel evaporator has excellent anti-salt properties, antimicrobial properties, and recyclability. This work provides valuable guidance for designing and developing practical hydrogel evaporators.

Voltametric detection of methylene blue dye in water at green and chemically synthesized Ag/MWCNT modified electrode

Abstract A well-known textile dye, methylene blue (MB) was electrochemically detected by using glassy carbon electrode (GCE), modified with green and chemically synthesized silver nanoparticles (AgNPs) decorating the surface of functionalized multiwalled carbon nanotubes (fMWCNT). The green and chemical methods were used to synthesize AgNPs, which decorated MWCNT forming MWCNT/Agchm and MWCNT/Aggrn nanocomposite. Comprehensive characterization of the nanomaterials was carried out using energy-dispersive x-ray spectroscopy (EDX) detector-equipped scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV), and x-ray diffraction (XRD). Using XRD, particle sizes were found to be 26.81, 10.05, 5.36, 19.26, and 17.48 nm for Agchm, Aggrn, MWCNT, Agchm/MWCNT, and Aggrn/MWCNT, respectively. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV) were employed for the investigation of the electrochemical properties and behaviour of MWCNT, Agchm, Aggrn, Agchm/MWCNT, and Aggrn/MWCNT electrodes, and higher electron transport capabilities and improved electrochemical activity towards MB on Agchm/MWCNT electrode were demonstrated by the results. Electroanalysis of methylene blue at the modified electrodes with square wave technique SWV was successful. At Agchm/MWCNT modified electrode, a low limit of detection (LOD) of 4.684 and limit of quantification (LOQ) of 14.194 pM, for MB, while at Aggrn/MWCNT modified electrode , an LOD and LOQ of 2.935 and 8.895 pM, were recorded respectively. In real sample analysis, the recovery percentage for Agchm/MWCNT ranged from 90 to 98% (n =3), and Aggrn/MWCNT showed a recovery percentage ranging from 97 to 103% (n = 3). Both electrodes’ remarkable recovery rate attest to their dependability and sensitivity in MB detection.