Stable Surface Research Articles

Assessing decadal soil redistribution rates using 239+240Pu across diverse lithologies in Southeast Alaska

AbstractQuantifying soil redistribution rates, including both erosion and deposition, is critical for understanding erosion processes, landscape evolution, land management strategies, and the carbon cycle. In the Northeast Pacific coastal temperate rainforest, the interaction of perhumid climate and dense coniferous forest tends to form Spodosols which are soils characterized by a subsurface accumulation of organic matter and iron and aluminum oxides, across a range of contrasting lithologies. Deep Spodosols are frequently found on steep backslopes (up to 60%) of colluvial deposits, where shallower soils would typically be expected. We hypothesized that deep Spodosols in Southeast Alaska indicate slope stability, exhibiting negligible soil redistribution rates and stable surfaces regardless of the lithology. Our objective was to quantify soil redistribution rates for Spodosols formed on steep slopes across a range of lithologies in hilly and mountainous areas of Juneau, AK. We used 239+240Pu isotopes to quantify soil erosion and deposition rates in Spodosols formed on colluvial deposits from tonalite, slate, metavolcanic rock, and phyllite. 239+240Pu measurements revealed negligible soil redistribution rates for all studied pedons, ranging from erosion rates of 0.51 t/ha/year to deposition rates up to 0.43 t/ha/year. No difference was detected between the hill and mountain landforms, further supporting the idea that Spodosols could indicate slope stability over decadal timescales across the region. Understanding the resilience of Spodosols to erosion processes in varied lithologies and landforms on steep slopes is paramount for making informed decisions regarding sustainable land use, landslide risk mitigation, and effective carbon sequestration strategies.

Flexible, transparent, and durable slippery liquid‐infused porous surface achieved by void‐centered PVDF‐co‐HFP membrane for self‐cleaning antifog coating

AbstractBioinspired smart surfaces, such as slippery liquid‐infused porous surfaces (SLIPS), have garnered significant attention due to their efficacy in self‐cleaning, antifouling, and antibacterial applications. Despite their advantages, SLIPS exhibit limitations such as compromised transparency, insufficient stability, and limited slippery performance, which have hindered their widespread practical use. To address these challenges, this article proposes a rational design utilizing a void‐centered poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF) membrane for slippery liquid‐infused porous surfaces with exceptional flexibility, transparency, durability, and superior slippery performance. These advancements promise to enhance high‐performance, self‐cleaning, and antifogging coatings. The membranes, featuring large‐area, thickness‐customizable void‐centered PVDF, are fabricated through a two‐step process involving phase separation and selective etching. The utilization of PVDF polymer, which has a refractive index similar to that of silicon‐based lubricant oil, enhances transparency, while macrovoids positioned at the membrane's center, acting as oil reservoirs, improve the stability and performance of the SLIPS surfaces. Experimental findings demonstrate remarkable transparency of up to 93% in the visible light range and a lubricant oil uptake of 2.32 at a porosity of 70%. Moreover, the developed SLIPS exhibit outstanding durability, maintaining slippery performance with sliding angles of <10° following exposure to either 400 consecutive droplets or aging for up to 40 days. This study significantly contributes to the development of future SLIPS, particularly for applications such as antifogging coatings on vehicle glass and solar panels, and self‐cleaning surfaces.

Enhanced performance of amine and thiol chemically modified graphene oxide for effective removal of Hg(II), Pb(II), and Cr(VI) from aqueous solution

This study describes a novel adsorbent with a multidentate ligand that was facilely fabricated by covalently bonding 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole on graphene oxide (AHMT-PRGO). The AHMT-PRGO nano-adsorbent was used for the effective removal of Hg(II), Pb(II), and Cr(VI) from wastewater. The AHMT-PRGO nano-adsorbent was synthesized by a nucleophilic substitution reaction between GO acyl chloride and AHMT chelating ligand in the presence of tetrabutyl-ammonium bromide as a catalyst. The successful modifications were confirmed via several spectroscopic and electron microscopy instrumentations including UV–Vis, FTIR, Raman, XRD, XPS, SEM, and TEM. The maximum adsorption capacities of Hg(II), Cr(VI), and Pb(II) on the AHMT-PRGO nano-adsorbent were 370.0, 136.2, and 109.6 mg/g, respectively, exceeding those of most previously reported adsorbents. Additionally, the equilibrium contact times for Hg(II), Pb(II), and Cr(VI) were 60, 30, and 400 min, respectively. In a mixture of nine heavy metal ions containing 250 ppm of each ion, the AHMT-PRGO nano-adsorbent exhibited high selectivity for Hg(II) ions. Furthermore, the AHMT-PRGO nano-adsorbent showed high stability over five adsorption–desorption cycles. Additionally, the AHMT-PRGO nano-adsorbent was successfully applied to remove heavy metal ions from real water samples. The novelty of AHMT-PRGO lies in the combination of a multidentate ligand for strong and selective binding with the high surface area and stability offered by covalently bonded graphene oxide. This combination offers potential advantages over traditional adsorbents in terms of adsorption capacity, selectivity, and reusability.

Surface dissipation and foliar penetration of acetamiprid on tea leaves in the presence or absence of adjuvants

This study is to investigate the surface dissipation and foliar penetration of acetamiprid following application to live tea plants in the presence and absence of two adjuvants (Alligare 90® and Peptoil®). SERS mapping protocol with a self-assembled AuNP mirror as substrates was utilized for in situ and real time pesticide analysis. The surface dissipation analysis showed that acetamiprid with Alligare 90® had the lowest dissipation rate (34%) compared to acetamiprid alone (60%) or with Peptoil® (44%), indicating the addition of Alligare 90® was more effective in reducing the surface dissipation of acetamiprid than Peptoil®. The study also investigated the foliar penetration of acetamiprid into tea leaves with and without adjuvants using SERS and LC-MS/MS. The study concludes that the two adjuvants tested can enhance spreadability, surface stability, and foliar penetration of acetamiprid applied on tea leaves. The information will facilitate the development and application of efficient and safe pesticide formulations.

Recent advances on hydrogen generation based on inorganic metal oxide nano-catalyst using water electrolysis approach

Abstract Today world is looking for a cheap, environment friendly and efficient substitute of fossil fuel. Because due to large consumption of the fossil fuels on daily basis in whole world, emission of hazardous gases have produced lethal effects on human being. In this scenario hydrogen energy has emerged in form of clean, renewable and more efficient energy. Now the key challenge is that efficient production of the green hydrogen at commercial scale to meet demand of hydrogen. The electrolysis of water is the best pathway to achieve efficient hydrogen production. For this purpose the synthesis and improvement of low cast, active as well as stable catalysts or electrolysis is prerequisite for hydrogen production by electro-catalytic method for splitting of water. Main focus of this review is that, how we can perform the electrolysis of water by various techniques using novel methods especially electro-catalysts in term of activity, efficiency, large surface area, porosity, and stability. This will be performed by the method of two-half cell reaction one is the Hydrogen Evolution Reaction (HER) other one Oxygen Evolution Reaction (OER), where reaction proceeded in both medium acidic as well as alkaline phases. Particular attention is given to produce green clean hydrogen production from usable water and its physical and chemical storages for further uses for the support of human sustainability. Basically the recent strategy is to prepare, design and development of nanoscale materials/composite with non-noble metals and with also nanostructured with noble-metals will be discussed in this approach. The increased efficiency and utility have been the focal points of the use of diverse materials from different classes. To increase the electro-catalytic efficiency in OER and HER, we will discuss about new analyses methods and insights into studying the chemical compositions, shapes, surface area, porosity, and synergy of catalysts and the active sites of nanostructured electro-catalysts. This review will further provide the picture of current state of developments as well as recent progress for mechanized efficient production of clean hydrogen (i.e., HER) from water by electrocatalytic method using various nanoscale materials in a broad scale.

Mechanical and Corrosion Properties of Super Austenitic Stainless Steel Joint for Double‐Sided Synchronous TIP TIG Arc Butt Welding

Super austenitic stainless steel 254SMO (254SMO SASS) plates are joined by double‐sided double‐arc synchronous TIP TIG butt welding (DSSTTABW) using ER NiCrMo3 wire, and the micro‐structure, mechanical and corrosion properties of 254SMO SASS joints are investigated subsequently. Results show that solidification grain boundary and solidification sub‐grain boundary can be observed in fusion zone. A small amount of σ phase precipitates in the weld, while χ phase is found in the transition zone, but no solidification crack occurs in weld and heat affected zone (HAZ). 254SMO SASS joint has higher micro‐hardness and lower tensile strength and elongation compared to base metal. During transverse tensile process, 254SMO SASS joints fail in the weld zone in a ductile mode. Electrochemical corrosion performance tests indicate that 254SMO SASS joint achieve equivalent pitting corrosion resistance and similar passive mechanism to base metal in 3.5 wt% NaCl solution. The passivation film on the surface of both joint and base metal display as n‐p semi‐conductive character, but the film stability of 254SMO joint surface is slightly poorer compared to base material. The surface passivation film of 254SMO joint primarily consists of oxides of Fe, Cr, and Mo before potentiodynamic polarization, while hydroxides of Fe and Cr are also observed after polarization.

Rationalizing Acidic Oxygen Evolution Reaction over IrO2: Essential Role of Hydronium Cation.

The development of active, stable, and more affordable electrocatalysts for acidic oxygen evolution reaction (OER) is of great importance for the practical application of electrolyzers and the advancement of renewable energy conversion technologies. Currently, IrO2 is the only catalyst with high stability and activity, but a high cost. Further optimization of the catalyst is limited by the lack of understanding of catalytic behaviors at the acid-IrO2 interface. Here, in strong interaction with the experiment, we develop an explicit model based on grand-canonical density function theory (GC-DFT) calculations to describe acidic OER over IrO2. Compared to the explicit models reported previously, hydronium cations (H3O+) are introduced at the electrochemical interface in the current model. As a result, a variation in stable IrO2 surface configuration under the OER operating condition from previously proposed complete *O-coverage to a mixture coverage of *OH and *O is revealed, which is well supported by in situ Raman measurements. In addition, the accuracy of predicted overpotential is increased in comparison with the experimentally measured. More importantly, an alteration of the potential limiting step from previously identified *O → *OOH to *OH → *O is observed, which opens new opportunities to advance the IrO2-based catalysts for acidic OER.

Polyvinylidene fluoride-based loose nanofiltration membrane with graphene oxide intercalation for efficient small organic molecules desalination

Graphene oxide (GO) loose nanofiltration (LNF) membranes show immense potential for the desalination of small organic molecules. However, it remains a significant challenge to compare the performance of GO LNF membranes prepared via different doping methods and study the mechanisms that influence the separation abilities of the membranes. In this study, LNF membranes prepared via three GO doping methods were examined for flux, retention rate, and the separation performance of small organic molecules and inorganic salts. The membranes coated with dopamine (DA) and GO, and subsequently formed polydopamine (PDA)–GO intercalation, showed the best results. A novel LNF membrane material (PVDF/PDA–GO–TFN; PVDF: polyvinylidene fluoride, TFN: thin-film nanocomposite) was developed to enhance the separation performance of small organic molecules and inorganic salts while improving membrane surface stabilization and anti-fouling performance and reducing the “trade-off” effect. The optimal conditions for PDA–GO intercalation and the best combination for interfacial polymerization (IP) were also determined. The intercalation structure was identified via scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, atomic force microscopy, and Fourier-transform infrared spectroscopy. Furthermore, the separation mechanism of the membrane was determined to be based on the Donnan and steric hindrance effects, according to the correlation analysis of the membrane surface electrical properties (zeta potential), hydrophilicity (contact angle), and pore properties. The PVDF/PDA–GO–TFN LNF membrane displayed a maximum water permeance of 10.45 L/(m2·h·bar), with an 88 % rejection of PEG2000 and a 6.83 % rejection of Na2SO4. Moreover, the membrane exhibited excellent anti-fouling performance and long-term stability, with a mean flux recovery rate of 99.06 % after four cycles of filtration and backwashing tests using small organic molecules and inorganic salt solutions. The inorganic salt retention rate was analyzed using SPSS software, and the results indicated excellent membrane stability. In summary, the preparation of PVDF/PDA–GO–TFN membrane materials provides a novel approach for fabricating LNF membranes that can effectively separate small organic molecules and inorganic salts.

Energetic, electronic structure and work function of the (0001), (10 [formula omitted] 0), and (11[formula omitted] 0) BaAl2O4 surfaces; A first-principles study

In this study, the GGA-PBE method was applied to explore the electronic structure and properties of the BaAl2O4 surfaces. We found that the most stable surfaces are non-polar surfaces containing Ba and O atoms in their outermost layers. From an energetic point of view, the surface energy of these surfaces is arranged as follows; γ(101‾0)<γ(0001)<γ(112‾0). The electronic structure of each surface is discussed in detail through PDOS curves and particular interest has been devoted to the origin of surface states. On the other hand, our results showed that the work function value of BaAl2O4 strongly depends on the nature of its surface termination. These results revealed that the BaO-terminated (101‾0) and (0001) surfaces have work function values of 0.95 eV and 0.8 eV and negative electron affinities (NEA) of −0.3eV and −0.56eV, respectively. Based on these results, we suggest that BaAl2O4 may be a good candidate for use in thermionic converters and electron-emission devices.

Visualization and standardized quantification of surface charge density for triboelectric materials

Triboelectric nanogenerator (TENG) operates on the principle of utilizing contact electrification and electrostatic induction. However, visualization and standardized quantification of surface charges for triboelectric materials remain challenging. Here, we report a surface charge visualization and standardized quantification method using electrostatic surface potential measured by Kevin probe and the iterative regularization strategy. Moreover, a tuning strategy on surface charge is demonstrated based on the corona discharge with a three-electrode design. The long-term stability and dissipation mechanisms of the injected negative or positive charges demonstrate high dependence on deep carrier traps in triboelectric materials. Typically, we achieved a 70-fold enhancement on the output voltage (~135.7 V) for the identical polytetrafluoroethylene (PTFE) based TENG (neg-PTFE/PTFE or posi-PTFE/PTFE triboelectric pair) with stable surface charge density (5% decay after 140 days). The charged PTFE was demonstrated as a robot e-skins for non-contact perception of object geometrics. This work provides valuable tools for surface charge visualization and quantification, giving a new strategy for a deeper understanding of contact electrification.

A comparative study for ferro particles cloaking and wetting characteristics

Ferro hydrophobic particles possess essential properties for controlling the behavior of suspended substances in water. By adjusting the concentration of these particles, the magnetic force within the fluid carrier can be modified, leading to the emergence of distinct flow structures and patterns on the water's surface. This study examines the cloaking phenomenon exhibited by different ferroparticle conditions, employing both experimental and numerical approaches. Under the magnetic influence, hydrophilic particles can attain cloaking velocities of up to 35 mm/s, while hydrophobic particles remain unaffected by the magnetic force, remaining suspended on the water's surface. Hydrophobization of ferroparticles not only decreases their water-cloaking ability but also alters their magnetic properties. The inherent hydrophobic nature of these particles enhances water surface stability, rendering them valuable in various applications, including biomedical and self-cleaning technologies. This research holds particular significance for manipulating suspended particles in water, particularly in biomedical applications like drug delivery and tissue engineering, as well as for advancing self-cleaning technologies.

Vertebrates from the Late Miocene of Salinas Grandes de Hidalgo (central Argentina). New faunal data: biochronological and paleoenvironmental considerations

ABSTRACT Salinas Grandes de Hidalgo (La Pampa Province) is a relevant locality of the Cerro Azul Formation in central Argentina because of its abundant and diverse vertebrate remains, including representatives of Reptilia, Aves and mostly Mammalia. Concerning previous records, the present faunal list adds one Argyrolagidae marsupial, one Ctenomyidae and two Caviidae rodents, as well as the first detailed analysis and description of glyptodonts from the Cerro Azul Formation in La Pampa Province. New geological information is added about the two fossiliferous outcrops included in Salinas Grandes de Hidalgo area. The classically studied outcrop located in the saline lake and the nearby one in the so-called ex-Autódromo, both herein correlated based on lithostratigraphy, particularly by the presence of paleosols in the intermediate section of the sedimentary succession. These sandy silts deposits in the base of the outcrops indicate the development of poorly confined flows and intervals of surface stabilisation by paedogenesis. We offer a biochronological interpretation based on a recently published U-Pb detrital zircons dating (5.9 ± 0.4 Ma) and the presence of significant taxa such as octodontoid rodents recovered from the dated levels and below it. From a paleoenvironmental viewpoint, we infer variations from woodlands to open environments.

Multimodal training protocols on unstable rather than stable surfaces better improve dynamic balance ability in older adults

BackgroundThere has been growing interest in using unstable devices in training protocols. This study aimed to assess the effectiveness of two multimodal exercise interventions (i.e., on stable and unstable surfaces) on dynamic balance control and lower limb strength in older adults.MethodsSixty-two older adults were randomly assigned to two intervention groups (N = 20, stable group; N = 19, unstable group), and to a control group (N = 18). In this single-blinded randomized controlled study, the two intervention groups underwent a 12-week training program twice a week for 45 min, consisting of strength and balance exercises. The stable (ST) group performed the training program over stable surfaces, while the unstable (UNST) group over unstable surfaces. Dynamic balance was assessed by computing the center of pressure (CoP) trajectory while a driven movable platform induced an unexpected perturbation of the base of support. Specifically, we considered the following CoP-related parameters within a 2.5-s temporal window from the beginning of the perturbation: displacement (Area95), mean velocity (Unit Path), anterior–posterior first peak (FP), post perturbation variability (PPV), and maximal oscillations (ΔCoPMax). The dominant quadriceps strength was measured through an isometric maximal voluntary contraction on an instrumented chair.ResultsFour out of five CoP-related parameters (i.e., Area95, Unit Path, ΔCoPMax, and PPV) significantly improved in the UNST group from a minimum of 14.28% (d = 0.44) to a maximum of 52.82% (d = 0.58). The ST group significantly improved only in two (i.e., ΔCoPMax, and PPV) out of five CoP-related parameters with an enhancement of 12.48% (d = 0.68) and 19.10% (d = 1.06). Both intervention groups increased the maximal isometric quadriceps strength (UNST:17.27%, d = 0.69; ST:22.29%, d = 0.98). The control group did not show changes in any of the parameters considered.ConclusionsStable surfaces promoted faster increments of muscular strength. Unstable surfaces were more effective in enhancing dynamic balance efficiency. These findings suggested the employment of multimodal training on unstable rather than stable surfaces to potentially lower the incidence of falls in older adults.Trial registrationNCT 05769361, retrospectively registered 13 March 2023, https://clinicaltrials.gov/study/NCT05769361?lat=45.3661864&lng=11.8209139&locStr=Padova,%20Italy&distance=50&page=11&rank=107.

Biocompatible Preparation of Beta-Lactoglobulin/Chondroitin Sulfate Carrier Nanoparticles and Modification of Their Colloidal and Hydropathic Properties by Tween 80.

The electrostatic complexation of the protein beta-lactoglobulin (β-LG) with the anionic polysaccharide chondroitin sulfate (CS) and the subsequent stabilization by thermal treatment were studied to achieve the well-defined nanoparticles (NPs). The formation of the well-defined NPs was obtained at pH 4 with a hydrodynamic radius from 60 to 80 nm. NP aggregation was observed at pH 1.5 because of the loss of the anionic charge of chondroitin sulfate on the surface of the NPs. After thermal treatment, the NPs exhibited stability against a pH increase to pH 7 while a stronger aggregation at pH 1.5 was observed. Core-shell structures were found at pH 7 after thermal treatment, indicating a possible mechanism of partial disintegration. The addition of Tween 80 (T80) before thermal treatment led to the formation of T80 self-assemblies inside the NPs. This caused an increase in the hydrophobicity of the inner and outer surfaces of the NPs as it was observed by fluorescence spectroscopy. The ζ-potential of the complexes and NPs was about -20 mV while the presence of T80 did not affect it. FTIR spectra verified changes of the secondary structure of β-LG in its complexes with CS and T80. The thermally treated NPs exhibited high surface and overall hydrophobicity and stability in high salinity and biocompatible solutions. The thermally treated NPs showed colloidal and physicochemical stability for 1 month, which were enhanced by the addition of T80. Due to the nature of the precursors and their colloidal properties, the NPs are highly promising for applications as biocompatible drug delivery nanocarriers while T80 acts as an agent to modify their properties.

Atomistic structures and stabilities of MgAl2O4 surfaces under processing conditions: A first-principles thermodynamics study

Surfaces, in contacting ambient environments, are of particular importance for controlling sintering, thin-film growth, and catalytic activity of oxides. Magnesium aluminate spinel (MgAl2O4), an essential oxide for both functional and structural ceramics, has attracted considerable attentions across diverse scientific fields. Nonetheless, a central challenge in rationally manipulating the properties of MgAl2O4 lies in the atomistic understanding of its surface structures under processing conditions. This study presents comprehensive first-principles calculations of MgAl2O4 (110) and (111) polar surfaces with/without off-stoichiometries. We predict from a thermodynamic model the dependence of surface stabilities on critical processing parameters, namely the oxygen partial pressure (PO2) and temperature (T). The findings indicate that at typical sintering temperatures, the non-stoichiometric (110) surface transits from Al/Mg-rich to O-rich with increasing PO2. In contrast, the non-stoichiometric (111) surface stably terminates in a Mg-rich configuration at low PO2, gradually shifting to Al-rich and then to Mg/O-rich as PO2 increases. The correlation between surface off-stoichiometry and stability is elucidated through electronic structure analysis. The investigation offers fundamental insights into surface structures and physicochemical behavior of MgAl2O4, thereby facilitating the rational processing control of complex oxides for applications in catalysis and electronics.

Long-Term Prevention of Biofilm Formation by Polycatechol-Based Supramolecular Assemblies with Low Molecular Weight Polymers on Surfaces.

Achievement of a stable surface coating with long-term resistance to biofilm formation remains a challenge. Catechol-based polymerization chemistry and surface deposition are used as tools for surface modification of diverse materials. However, the control of surface deposition of the coating, surface coverage, coating properties, and long-term protection against biofilm formation remain to be solved. We report a new approach based on supramolecular assembly to generate long-acting antibiofilm coating. Here, we utilized catechol chemistry in combination with low molecular weight amphiphilic polymers for the generation of such coatings. Screening studies with diverse low molecular weight (LMW) polymers and different catechols are utilized to identify lead compositions, which resulted in a thick coating with high surface coverage, smoothness, and antibiofilm activity. We have identified that small supramolecular assemblies (∼10 nm) formed from a combination of polydopamine and LMW poly(N-vinyl caprolactam) (PVCL) resulted in relatively thick coating (∼300 nm) with excellent surface coverage in comparison to other polymers and catechol combinations. The coating properties, such as thickness (10-300 nm) and surface hydrophilicity (with water contact angle: 20-60°), are readily controlled. The optimal coating composition showed excellent antibiofilm properties with long-term (>28 days) antibiofilm activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) strains. We further utilized the combination of optimal binary coating with silver to generate a coating with sustained release of silver ions, resulting in killing both adhered and planktonic bacteria and preventing long-term surface bacterial colonization. The new coating method utilizing LMW polymers opens a new avenue for the development of a novel class of thick, long-acting antibiofilm coatings.

Enhanced surface stability of K0.27MnO2·0.54 H2O cathode materials with LiF/LixPFyOz coating for potassium-ion batteries

Manganese based oxides have significant potential as cathode materials for potassium ion batteries (PIB). Unfortunately, the practical application of manganese-based oxides is hindered by severe electrode surface erosion from electrolyte decomposition products and material expansion and collapse during potassium ion intercalation. Consequently, the surface modification strategy is adopted herein to uniformly cover the surface of K0.27MnO2·0.54 H2O (KMO) microspheres with LiF/LixPFyOz coating to effectively protect the electrode surface and significantly inhibit the collapse of the material crystal structure. Additionally, the coating exhibits excellent electron/ion conductivity, enhancing the diffusion efficiency of potassium ions within the electrode material. The existence of LiF/LixPFyOz coating is confirmed by characterization measurements. The LiF/LixPFyOz-coated KMO microspheres (sample LLO@KMO-2) exhibit outstanding cyclic stability (66.3 % capacity retention at 50 mA g−1) and high discharge capacity (100.2 mAh g−1 at 50 mA g−1), demonstrating their excellent cycle stability. The modification strategy of LiPF6-electrolyte-solvothermal coating provides an innovative surface modification method for potassium ion batteries, showcasing its potential for application in future high-performance battery technologies.

Functional cellulose interfacial layer on zinc metal for enhanced reversibility in aqueous zinc ion batteries

Aqueous zinc ion batteries have emerged as promising energy storage devices due to their high safety, cost-effectiveness, and environmental friendliness. However, the practical implementation of zinc ion batteries faces significant challenges associated with the poor surface stability of Zn metal anode, including dendrite growth, side reactions, and poor cycling stability. Herein, an eco-friendly cellulose layer is applied to the Zn metal anode by a scalable coating method for Zn/electrolyte interfacial engineering. The cellulose coating has multiple functions: physical passivation, reducing the resistive native oxide, enhancing wettability between the Zn metal and electrolyte, and facilitating the insertion and extraction of zinc ions during charge–discharge cycles at both room temperature and low temperature (−10 ℃). The cellulose-coated Zn metal anode (ZCL) also inhibits the formation of zinc dendrites, thereby reducing the risk of short circuits and capacity loss. As a result, the ZCL||ZCL symmetric cell achieved 1000 electrochemical cycles at 2 mA cm−2, which is more than eight times longer compared to that of a bare Zn symmetric cell. The electrochemical performance of the ZCL||MnO2 full cell was also found to be superior to that using the bare Zn anode electrode.

Highly adhesive bioinspired membrane for efficient oil/water separation by optimization of synergistic effects of hierarchical structure and superhydrophobic modification

Superwetting membranes have good prospective for treatment of oil-containing wastewaters. However, development of highly adhesive superhydrophobic membranes with efficient oil-water separation performance remains a great challenge that needs to be addressed urgently. Herein, highly adhesive membrane surface with hierarchical structure were fabricated by in-situ TEOS hydrolysis and fluorinated modification. The interface bonding force between polyvinylidene fluoride (PVDF) and silica nanoparticles (SiO2 NPs) was increased through the dopamine self-polymerization and adhesion. The hierarchical structure was obtained by simultaneously adjusting TEOS and ammonia contents. The three-dimensional hierarchical membrane structure which is similar to that of a rose petal was shown by SEM analysis. The obtained membrane showed a water contact angle of 158 ± 2°, while the oil contact angle approaches 0°. In-situ grown multi-scale SiO2 NPs, perfluorooctyltriethoxysilane (FAS) brushes and dopamine can form a stable hierarchical surface which sustained superhydrophobicity/superoleophilicity when immersed in aqueous solutions at different pH values. Meanwhile, FAS brushes can serve as steric obstacles to efficiently repel water droplets during oil/water separation. The fabricated membrane possesses a high permeation flux and excellent separation properties (> 98%). In addition, this highly adhesive coating modification and hierarchical design can be widely applied on the surfaces of different materials, giving an attractive potential application prospect, such as oil/water separation, antifouling surface, and superwetting materials.

Hydrogen-bonded micelle assembly directed conjugated microporous polymers for nanospherical carbon frameworks towards dual-ion capacitors

Well-orchestrated carbon nanostructure with superb stable framework and high surface accessibility is crucial for zinc-ion hybrid capacitors (ZIHCs). Herein, a hydrogen-bonded micelle self-assembly strategy is proposed for morphology-controllable synthesis of conjugated microporous polymers (CMPs) derived carbon to boost zinc ion storage capability. In the strategy, F127 micellar assembly through intermolecular hydrogen bonds serves as structure-directed agents, directing CMPs’ oligomers grow into nanospherical assembly. The nanospherical carbon frameworks derived from CMPs (CNS-2) have shown maximized surface accessibility due to their plentiful tunable porosity and hierarchical porous structure with abundant mesoporous interconnected channels, and superb stability originating from CMPs’ robust framework, thus the CNS-2-based ZIHCs exhibit ultrahigh energy density of 163 Wh kg−1 and ultralong lifespan with 93 % capacity retention after 200, 000 cycles at 20 A g−1. Charged ion storage efficiency also lies in dual-ion alternate uptake of Zn2+ and CF3SO3− as well as chemical redox of Zn2+ with carbonyl/pyridine motifs forming O–Zn–N bonds. Maximized surface accessibility and dual-ion storage mechanism ensure excellent electrochemical performance. Thus, the hydrogen-bond-guide micelle self-assembly strategy has provided a facile way to design nanoarchitectures of CMPs derived carbon for advanced cathodes of ZIHCs.