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Sand is one of the most fundamental construction materials that is of significant importance and widely used for making concrete, plasters, and mortars, and also for filling under floor and basements. Sand-derived functional materials, for instance superhydrophobic sand, which can be used to prepare liquid marble, separate oil-water mixtures, and transport liquids, have recently been a highly topical and promising research field. However, such materials are mainly prepared using valuable surface modification agents via complicated procedures that are difficult for mass-production, which restricted their true applications. Here, we developed a simple, low-cost, and efficient method for the development of sand-based hierarchical micro/nanostructured composite materials with diverse applications. Briefly, micro/nanostructured superhydrophobic sand was synthesized by one-step in situ growth of a network layer of silicone nanofilaments on the surface of sand microparticles, using only one cheap chemical of small molecules of silanes. The as-prepared superhydrophobic sand displays excellent performance in waterproofing, water storage, soil moisturizing, and oil-water separation. Furthermore, sand-supported micro/nanocomposite catalysts were obtained through covalent attachment of polyamines on the surface of silicone nanofilaments. Such composites, packed in a glass column, were used as a simple flow reactor for Knoevenagel condensation reactions. Quantitative amounts of pure products without further purification can be obtained in such a simple way that just allowing the reactants solution flows through the composite catalysts driven by gravity. These results pave the way toward the development of sand-based multifunctional materials with great potential for industrial use, given their versatile functions and excellent performances but easy-to-fabricate, low-cost preparation procedure.

Soil-plant interactions and root water uptake are important factors of the soil-plant-atmosphere continuum. Characterizing root water uptake dynamics in different forest stands can help to predict water stress due to climate change. Governing factors that define tree root water uptake are environmental conditions, soil hydraulic properties, species-specific rooting patterns as well as intra- and interspecific competition. As spatial-temporal patterns of root water uptake cannot be measured directly, simplified assumptions are often either based upon homogenous soil conditions or on a static root water uptake profile. This study combines high-resolution in-situ measurements of water stable isotopes of xylem and soil moisture with a set of 1D soil hydrological and transport models of the vadose zone (Hydrus 1D) to investigate dynamics in root water uptake patterns of two competing tree species in three different forest stands. We measured in-situ water isotopic signature in different soil depths as well as in spruce and beech xylem continuously for two vegetation periods (2021-2022) including two artificial tracer experiments, a wet period in 2021 and a drought period in 2022. Three stands were compared: i) pure beech, ii) pure spruce and iii) mixed beech and spruce, measuring sap flux, leaf water potential, soil moisture, matric potential, throughfall and stemflow. In order to address different factors of soil heterogeneity, the vadose zone is represented by a set of models covering the range of measured soil conditions. Each model is calibrated against soil water content as well as isotope measurements and subsequently related to sap flux measurements. This allows for separating effects of soil heterogeneity and to analyze the interplay of a) stand specific factors, particularly different rooting distributions, interception, and throughfall patterns, and b) soil specific factors, particularly different hydraulic conductivity and plant available water fractions under changing environmental conditions. Results show that this interplay between soil and stand specific factors is crucial under dry conditions, while soil specific factors are of minor importance under wet conditions. This contribution will present and discuss results from this data-driven modelling study and provide information about how well processes are represented in these kind of models.

A vast majority of studies investigating the source depths in the soil of root water uptake with the help of water stable isotopes implicitly assumes that the isotopic signatures of root water uptake and xylem water are identical. In this study we show that this basic assumption is not necessarily valid, since water transport between the root tips and an observed point above the root zone is not instantaneous. However, to our knowledge no study has yet tried to explicitly assess the distribution of water transport velocities within the xylem. With a dye tracer experiment we could visualize how the transport of water through the xylem happens at a wide range of velocities which are distributed unequally throughout the xylem. In an additional virtual experiment we could show that, due to the unequal distribution of transport velocities throughout the xylem, different sampling approaches of water stable isotopes might effectively lead to xylem water samples with different underlying age distributions.

Performance of engineered surfaces can be enhanced by making them hydrophobic or superhydrophobic via coating them with low-surface-energy micro- and nanopatterns. However, the wetting phenomena of particularly irregular shape and spacing (super)hydrophobic patterns such as polysiloxane coatings are not yet fully understood from a microscopic perspective. Here, we show a new method to collect 3D confocal images from irregular polysiloxane micro- and nanorods from a single rod resolution to discuss their wetting response over long liquid/solid interaction times and quantify the length and diameter of these rods. To collect such 3D confocal images, fluorescent dye containing water droplets were left on our superhydrophobic and hydrophobic polysiloxane coated surfaces. Then their liquid/solid interfaces were imaged at different staining scenarios: (i) using different fluorescent dyes, (ii) when the droplets were in contact with surfaces, or (iii) after the droplets were taken away from the surface at the end of staining. Using such staining strategies, we could resolve the micro- and nanorods from root to top and determine their length and diameter, which were then found to be in good agreement with those obtained from their electron microscopy images. 3D confocal images in this paper, for the first time, present the long-time existence of more than one wetting state under the same droplet in contact with surfaces, as well as external and internal three-phase contact lines shifting and pinning. In the end, these findings were used to explain the time-dependent wetting kinetics of our surfaces. We believe that the proposed imaging strategy here will, in the future, be used to study many other irregular patterned (super)antiwetting surfaces to describe their wetting theory, which is today impossible due to the complicated surface geometry of these irregular patterns.

The intensity and frequency of droughts events are projected to increase in future with expected adverse effects for forests. Thus, information on the dynamics of tree water uptake from different soil layers during and after drought is crucial. We applied an in situ water isotopologue monitoring system to determine the oxygen isotope composition in soil and xylem water of European beech with a 2-h resolution together with measurements of soil water content, transpiration and tree water deficit. Using a Bayesian isotope mixing model, we inferred the relative and absolute contribution of water from four different soil layers to tree water use. Beech took up more than 50% of its water from the uppermost 5 cm soil layer at the beginning of the 2018 drought, but then reduced absolute water uptake from the drying topsoil by 84%. The trees were not able to quantitatively compensate for restricted topsoil water availability by additional uptake from deeper soil layers, which is related to the fine root depth distribution. Absolute water uptake from the topsoil was restored to pre-drought levels within 3 wk after rewetting. These uptake patterns help to explain both the drought sensitivity of beech and its high recovery potential after drought release.

(Super)antiwetting shielding around engineering materials and protecting them against harsh environmental conditions have been achieved via growing various geometry polysiloxane (or silicone) patterns around them by using a droplet-assisted growth method, where the polymerization takes place inside of the water droplets acting as reaction vessels. The size and distribution of these reaction vessels are the main factors in making different geometry silicone patterns; however, very little is known about the fate of these droplets throughout the polymerization. Here, we propose keeping the relative humidity (% RH) inside the reactor stable throughout the polymerization as a new coating parameter to force the size of the reaction vessel water droplets to be the same for building simply shaped silicone rods with controlled geometry and distribution. In this manner, we grew simple geometry cylindric microrods on surfaces and could tune their length, diameter, inter-rod spacing, and thus the (super)hydrophobicity. Here, we also demonstrate that with changes in the amplitude and stability of the % RH, it is possible to fabricate different (super)hydrophobic nanograsses, conical silicone microrods, and isotropic silicone nanofilaments. The proposed new way of tuning initial and in situ reaction vessel droplet size can be used as a single factor to formulate different geometry silicone patterns with tunable dimensions, leading to different roughness and hydrophobicity. To a certain extent, the droplet size-assisted silicone shaping in this work provides a new way to control the length, diameter, morphology, inter-rod spacing, and thus the (super)hydrophobicity of the silicone patterns, especially those in the shape of simple cylindrical microrods. This control over silicone architecting will help to prepare new (super)hydrophobic coatings with more controlled morphology and thus wettability; on the contrary, it will support surface scientists modeling the connection between surface geometry and (super)antiwetting of such irregular pillared surfaces that remain elusive.

Flood marks are rarely utilized in hazard assessment, mainly because of a lack of data availability and accessibility and mistrust in their reliability. Challenging these common assumptions, we present an approach for evaluation and practical utilization of flood marks by the example of the Kinzig River, a Rhine tributary from the Black Forest with a history of severe floods. We combined written documents describing flood marks with field mapping at three study sites and collected information relating to 89 marks – about 50 % of them still preserved – which refer to ≥15 large floods between 1824 and 1991. The inclusion of a detailed historical-mark survey enabled an assessment of changes through time for each flood mark: they extend from small (±15 cm) imprecisions in mark heights to considerable uncertainties in position, height, and displayed date for some modified marks. Plausibility checks with further data nevertheless demonstrated good overall consistency. We then juxtaposed these marks with the current, modeled flood hazard maps. A wide agreement is apparent, in that the large majority of marks are situated at probable heights and within the modeled flooding area associated with extreme floods. For the few exceptions, we see plausible and historically sound reasons in changed local hydraulic conditions by flood protection walls, exceptional processes during a massive ice jam, and possibly also a local underestimation of hazard along Kinzig River tributaries. Overall, this study highlights (1) the broad availability of flood mark data, both on a larger spatial scale and with regard to already vanished marks, and (2) the significance of the marks, verified by further data, and also demonstrates (3) the possibility of a straightforward inclusion in hazard assessment. We thus encourage the systematic collection, maintenance, and integration of flood marks as responsible risk management, not least regarding their value in the wider context of risk awareness and memory.

Fiber reinforced polymer composites (FRPC) have gain rapid interest as light-weight and corrosion-resistant materials for various applications in marine infrastructure. Despite their advantages, FRPCs are still susceptible to other environmental factors present in the marine environment and manufactured mostly from non-renewable materials. This greatly affects the overall economic and environmental sustainability of such components. To determine the long-term suitability of various FRPCs for use in marine environments, this paper provides a holistic comparison of the performance of 16 FRPCs (four fiber types: glass, carbon, natural, basalt; and four polymer resins: epoxy, polyester, vinylester, thermoplastic) not only from a technical, but also from an economic, environmental and resource perspective. The resulting ranking not only assesses each material’s long-term potential, but also provides a detailed overview of individual strengths and weaknesses. Although ranked the lowest of all materials, the partial renewability of the natural fiber composites makes them an interesting material in the longer term. Therefore, we use the framework to evaluate a number of approaches aimed at improving the overall performance of these composites.

A new facility has been developed which allows for a stable and reproducible production of ambient-like model aerosols (PALMA) in the laboratory. The set-up consists of multiple aerosol generators, a custom-made flow tube homogeniser, isokinetic sampling probes, and a system to control aerosol temperature and humidity. Model aerosols containing elemental carbon, secondary organic matter from the ozonolysis of α-pinene, inorganic salts such as ammonium sulfate and ammonium nitrate, mineral dust particles, and water were generated under different environmental conditions and at different number and mass concentrations. The aerosol physical and chemical properties were characterised with an array of experimental methods, including scanning mobility particle sizing, ion chromatography, total reflection X-ray fluorescence spectroscopy and thermo-optical analysis. The facility is very versatile and can find applications in the calibration and performance characterisation of aerosol instruments monitoring ambient air. In this study, we performed, as proof of concept, an intercomparison of three different commercial PM (particulate matter) monitors (TEOM 1405, DustTrak DRX 8533 and Fidas Frog) with the gravimetric reference method under three simulated environmental scenarios. The results are presented and compared to previous field studies. We believe that the laboratory-based method for simulating ambient aerosols presented here could provide in the future a useful alternative to time-consuming and expensive field campaigns, which are often required for instrument certification and calibration.

Flood marks are rarely utilized in hazard assessment, mainly because of a lack of data availability and accessibility and mistrust in their reliability. Challenging these common assumptions, we present an approach for evaluation and practical utilization of flood marks by the example of the Kinzig River, a Rhine tributary from the Black Forest with a history of severe floods. We combined written documents describing flood marks with field mapping at three study sites and collected information relating to 89 marks – about 50 % of them still preserved – which refer to ≥15 large floods between 1824 and 1991. The inclusion of a detailed historical-mark survey enabled an assessment of changes through time for each flood mark: they extend from small (±15 cm) imprecisions in mark heights to considerable uncertainties in position, height, and displayed date for some modified marks. Plausibility checks with further data nevertheless demonstrated good overall consistency. We then juxtaposed these marks with the current, modeled flood hazard maps. A wide agreement is apparent, in that the large majority of marks are situated at probable heights and within the modeled flooding area associated with extreme floods. For the few exceptions, we see plausible and historically sound reasons in changed local hydraulic conditions by flood protection walls, exceptional processes during a massive ice jam, and possibly also a local underestimation of hazard along Kinzig River tributaries. Overall, this study highlights (1) the broad availability of flood mark data, both on a larger spatial scale and with regard to already vanished marks, and (2) the significance of the marks, verified by further data, and also demonstrates (3) the possibility of a straightforward inclusion in hazard assessment. We thus encourage the systematic collection, maintenance, and integration of flood marks as responsible risk management, not least regarding their value in the wider context of risk awareness and memory.

The amyloid-β peptide is correlated with Alzheimer's disease and is assumed to cause toxicity by its interaction with the neuron membrane. A custom-made microscope objective based on the supercritical angle technique was developed by our group, which allows investigation of interfacial events by performing surface-sensitive and low-invasive spectroscopy. Applied to Raman spectroscopy, this technique was used to collect information about the structure of polypeptides that interact with a supported lipid bilayer. Notably, the conformation used by amyloid-β(1-40) and amyloid-β(1-42) when interacting directly with or next to the supported lipid bilayer was characterized. We observed two distinct secondary structures, α-helix and β-sheet, which were exhibited by the peptide. These two structures were detected simultaneously. The propensity of the peptide to fold into these structures seemed dependent on both their number of amino acids and their proximity with the supported lipid bilayer. The α-helix structure was observed for amyloid-β(1-42) fragments that were closer to the lipid bilayer. Peptides that were located further away from the bilayer favored the β-sheet structure. Amyloid-β(1-40) was less prone to adopt the α-helix secondary structure.

The ecological impacts of climate change encompass significant consequences on the interactions of soil-plant-atmosphere-continuum and flux dynamics and will thus affect forest ecosystems. Much work needs to be done to understand the distribution of ecosystem specific flow pathways and the characteristic timescales of water movement. Understanding the linkages and interactions between water use strategies, water storage and competition effects can thereby provide valuable knowledge about drought resilience of different tree stands. We assessed water fluxes and their water stable isotopy at high temporal and spatial resolution to evaluate ecohydrological processes and competition effects on water use strategies in a mixed forest in south-west Germany. Measurements in pure and mixed tree stands with two temperate tree species, European beech (Fagus sylvatica, n=18) and Norway spruce (Picea abies, n=18), include sap flow, stem water content, in-situ water isotopy, radial stem growth and climate conditions. Furthermore, a terrestrial lidar scan provided tree anatomical characteristics. Our central hypothesis is that species identity and water competition between tree species is a major driver for ecohydrological flux dynamics. Thus, we aim to gain a comprehensive knowledge of water use strategies of the two dominating tree species and their competitive balance.First results from the wet summer of 2021 indicated that, spruce trees showed lower sap flux densities in mixed stands compared to pure stands. Inversely, beech trees in mixture with spruce had higher sap flux densities than in pure stands. Although we only observed small species-specific differences in stem water content, a competitive impact could be shown on spruce trees by a reduced leaf area density in mixed stand trees. Dynamics in water isotopy of beech trees provided further insight in water use strategies between different stands. Future work will focus on exploring ecohydrological feedback processes and water transit times with high temporal resolution in situ isotope and sap flow measurements and labelling campaigns.

At the catchment scale, incoming precipitation is typically partitioned into runoff and evapotranspiration. Most transit time modeling approaches focus on the runoff part of the water balance and are consequently evaluated with respect to water ages in streamflow. Nevertheless, most modeling approaches also include a more or less detailed representation of evapotranspiration. In order to evaluate whether a modeling approach appropriately captures evapotranspiration and its water ages, it is important to understand what processes are required to be considered in the models. While evaporation from the soil and canopy surfaces is relatively easy to observe, transpiration involves root water uptake from a range of depths below the soil surface and water transport within plants. In addition, experimental data to evaluate transit time models are sampled in different organs and locations of plants.We will present the results of studies dealing with the transit times of root water uptake (between precipitation and water uptake) and with transit times internally in trees (between water uptake at the root tips and transpiration at the leaves) in temperate forests. A novel in-situ measurement technique enabled us to measure stable water isotopes in the soil and within tree stem xylem with unprecedented temporal resolution and thereby enabled us to refine our understanding of plant water uptake and tree internal water transport. Based on our experimental observations, we developed a new approach to model water transport and hence water transit time internally in trees.

The diversity of fused filament fabrication (FFF) filaments continues to grow rapidly as the popularity of FFF-3D desktop printers for the use as home fabrication devices has been greatly increased in the past decade. Potential harmful emissions and associated health risks when operating indoors have induced many emission studies. However, the lack of standardization of measurements impeded an objectifiable comparison of research findings. Therefore, we designed a chamber-based standard method, i.e., the strand printing method (SPM), which provides a standardized printing procedure and quantifies systematically the particle emission released from individual FFF-3D filaments under controlled conditions. Forty-four marketable filament products were tested. The total number of emitted particles (TP) varied by approximately four orders of magnitude (10

Despite great scientific and industrial interest in waterproof cellulosic paper, its real world application is hindered by complicated and costly fabrication processes, limitations in scale-up production, and use of organic solvents. Furthermore, simultaneously achieving nonwetting properties and printability on paper surfaces still remains a technical and chemical challenge. Herein, we demonstrate a nonsolvent strategy for scalable and fast fabrication of waterproofing paper through in situ surface engineering with polysilsesquioxane nanorods (PSNRs). Excellent superhydrophobicity is attained on the functionalized paper surface with a water contact angle greater than 160°. Notably, the engineered paper features outstanding printability and writability, as well as greatly enhanced strength and integrity upon prolonged exposure to water (tensile strength ≈ 9.0 MPa). Additionally, the PSNRs concurrently armor paper-based printed items and artwork with waterproofing, self-cleaning, and antimicrobial functionalities without compromising their appearance, readability, and mechanical properties. We also demonstrate that the engineered paper holds the additional advantages of easy processing, low cost, and mechanochemical robustness, which makes it particularly promising for real world applications.

Main text This report presents the results of CCQM-K150, a key comparison between nine National Measurement Institutes (NMIs) which tested the capability of the NMIs to measure particle number concentration (in the range of 100 to 20 000 cm-3) using condensation particle counters (CPCs), and particle charge concentration (in the range of 0.15 to 3 fC cm-3) using aerosol electrometers (AEs). Measurements of aerosol particle number concentration are needed to demonstrate compliance to vehicle emission legislation and are becoming increasingly important in other areas such as ambient air and workplace monitoring. The measurements are typically carried out using condensation particle counters, which are calibrated using either reference CPCs or reference AEs. An analogous report is available for the CCQM-P189 comparison. CCQM-P189 was identical to and used the same experimental data as CCQM-K150 with one exception: data from TROPOS, which is not an NMI or Designated Institute (DI), were only included in CCQM-P189. CCQM-K150 was an amount-of-substance Track C comparison. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text This report presents the results of CCQM-P189, a pilot comparison between 10 laboratories which tested the participants’ capability to measure particle number concentration (in the range of 100 to 20 000 cm-3) using condensation particle counters (CPCs), and particle charge concentration (in the range of 0.15 to 3 fC cm-3) using aerosol electrometers (AEs). Measurements of aerosol particle number concentration are needed to demonstrate compliance to vehicle emission legislation and are becoming increasingly important in other areas such as ambient air and workplace monitoring. The measurements are typically carried out using condensation particle counters, which are calibrated using either reference CPCs or reference AEs. An analogous report is available for the CCQM-K150 comparison. CCQM-K150 was identical to, and used the same experimental data as CCQM-P189 with one exception: data from TROPOS, which is not a National Measurement Institute (NMI) or Designated Institute (DI), were only included in CCQM-P189. CCQM-P189 was an amount-of-substance Track C comparison. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Passive icephobic surfaces can provide a cost and energy efficient solution to many icing problems that are currently handled with expensive active strategies. Water-repellent surface treatments are promising candidates for this goal, but commonly studied systems, such as superhydrophobic surfaces and Slippery Liquid Infused Porous Surfaces (SLIPS), still face challenges in the stability and durability of their properties in icing environments. In this work, environmental icing conditions are simulated using an Icing Wind Tunnel, and ice adhesion is evaluated with a Centrifugal Adhesion Test. We show that superhydrophobic coral-like Silicone Nanofilament (SNF) coatings exhibit extremely low ice adhesion, to the point of spontaneous ice detachment, and good durability against successive icing cycles. Moreover, SNFs-based SLIPS show stably low ice adhesion for the whole duration of the icing test. Stability of surface properties in a cold environment is further investigated with water wettability at sub-zero surface temperature, highlighting the effect of surface chemistry on superhydrophobicity under icing conditions.

Performance of engineered surfaces can be enhanced by making them hydrophobic or superhydrophobic via coating them with low-surface-energy micro-and nano-patterns. However, the wetting phenomena of particularly irregular shape and spacing (super)hydrophobic patterns such as polysiloxane coatings are not yet fully understood from a microscopic perspective. Here, we show a new method to collect 3D confocal images from irregular polysiloxane micro-and nanorods from a single rod resolution to discuss their wetting response over long liquid/solid interaction times and quantify the length and diameter of these rods. To collect such 3D confocal images, fluorescent dye containing water droplets were left on our superhydrophobic and hydrophobic polysiloxane coated surfaces. Then their liquid/solid interfaces were imaged at different staining scenarios: (i) using different fluorescent dyes, (ii) when the droplets were in contact with surfaces, or (iii) after the droplets were taken away from the surface at the end of staining. Using such staining strategies, we could resolve the micro-and nanorods from root to top and determine their length and diameter, which were then found to be in good agreement with those obtained from their electron microscopy images. 3D confocal images in this paper, for the first time, present the long-time existence of more than one wetting state under the same droplet in contact with surfaces, as well as external and internal three-phase contact lines shifting and pinning. In the end, these findings were used to explain the time-dependent wetting kinetics of our surfaces. We believe that the proposed imaging strategy here will, in the future, be used to study many other irregular patterned (super)antiwetting surfaces to describe their wetting theory, which is today impossible due to the complicated surface geometry of these irregular patterns.

Tree water uptake processes and ecohydrological travel times have gained more attention in recent ecohydrological studies. In situ measurement techniques for stable water isotopes offer great potential to investigate these processes but have not been applied much to tree xylem and soils so far. Here, we used in situ probes for stable water isotope measurements to monitor the isotopic signatures of soil and tree xylem water before and after two deuterium-labeled irrigation experiments. To show the potential of the method, we tested our measurement approach with 20-year-old trees of three different species (Pinus pinea, Alnus incana and Quercus suber). They were planted in large pots with homogeneous soil in order to have semi-controlled experimental conditions. Additional destructive sampling of soil and plant material allowed for a comparison between destructive (cryogenic vacuum extraction and direct water vapor equilibration) and in situ isotope measurements. Furthermore, isotope-tracer-based ecohydrological travel times were compared to travel times derived from sap flow measurements. The time to first arrival of the isotope tracer signals at 15 cm stem hight were ca. 17 h for all tree species and matched well with sap-flow-based travel times. However, at 150 cm stem height tracer-based travel times differed between tree species and ranged between 2.4 and 3.3 d. Sap-flow-based travel times at 150 cm stem hight were ca. 1.3 d longer than tracer-based travel times. The isotope signature of destructive and in situ isotope measurements differed notably, which suggests that the two types of techniques sampled water from different pools. In situ measurements of soil and xylem water were much more consistent between the three tree pots (on average standard deviations were smaller by 8.4 ‰ for δ2H and by 1.6 ‰ for δ18O for the in situ measurements) and also among the measurements from the same tree pot in comparison to the destructive methods (on average standard deviations were smaller by 7.8 ‰ and 1.6 ‰ for δ2H and δ18O, respectively). Our study demonstrates the potential of semi-controlled large-scale pot experiments and very frequent in situ isotope measurements for monitoring tree water uptake and ecohydrological travel times. It also shows that differences in sampling techniques or sensor types need to be considered when comparing results of different studies and within one study using different methods.

Summary Conventional polyolefin separators suffer from poor wettability to liquid electrolytes (LEs). Although some modified separators exhibit improved wettability, they are hydrophilic, causing inevitable moisture uptake. Trace water could result in poor performance and safety hazard of Li metal batteries. Here, we report a design idea of superLEphilic/superhydrophobic and thermostable separators by modifying the Celgard separator using silicone nanofilaments. The separator features low moisture uptake (∼0%), fast LE diffusion (454 ms), and high LE uptake (287.8%), LE retention rate, and Li+ conductivity. Consequently, the Li/LiFePO4 cells show high cycling stability (96.05% after 350 cycles), good rate performance (125 mA h g−1 at 5.0 C), low resistance, and stable open circuit voltage at 160°C. Moreover, the separator could improve performance of the other Li metal batteries with high-voltage cathodes and the LiFePO4/graphite pouch cells. This work provides an avenue for designing advanced separators by using bioinspired superwetting surfaces., Graphical Abstract, Highlights • A superLEphilic/superhydrophobic separator is first reported for Li metal batteries • The separator has low moisture uptake and could improve performance of Li/Li cells • The separator features fast LE diffusion, high LE uptake, and Li+ conductivity • The separator could enhance performance of high-voltage Li metal batteries, Chemistry; Electrochemistry; Nanoelectrochemistry; Materials Science; Energy Materials

Nanostructured materials have shown extraordinary promise for high surface area applications. Here we report the design of polystyrene (PS)-silicone nanofilaments (SNFs) composites, which can be flexibly grown on various substrates. The high surface area achieved by the SNFs is further extended by grafting with polystyrene. By changing the polymerization conditions and post treatment methods, the morphology of grafted PS is easily tuned into three types: leaf-shaped, bead-shaped and well-wrapped. The tuneable morphology of PS is optimized for oil-water separation and photocatalytic reactions and exhibited improved performances.

Many novel icephobic coatings have been shown to exhibit low adhesion strength to ice grown at null or low velocity. Of these, few have been shown to also exhibit low adhesion strength to ice grown by impacting high velocity supercooled water droplets. Even fewer of these have been shown to exhibit low adhesion strength to ice grown over a range of environmental conditions. Those that have shown such behavior have been held back by their susceptibility to certain bands of UV-exposure. Here, icephobic coatings made from Silicone Nanofilament (SNF) networks grown on anodic metal oxide surfaces are presented. They show low ice adhesion strength for a range of impact icing conditions and exhibit good durability against the tested conditions. Additionally, their nano-porous structure provides enhanced lubricant retention when infused with oil. The described coatings are a promising candidate for supporting hybrid ice protection systems on aircraft, thereby reducing the energy needed for anti−/de-icing.

We developed a setup for a fully automated, high frequency in-situ monitoring system of the stable water isotopes Deuterium and 18O in soil water and tree xylem. The setup was tested for 12 weeks within an isotopic labelling experiment during a large artificial sprinkling experiment including three mature European beech (Fagus sylvatica) trees. Our setup allowed for one measurement every 12–20 minutes, enabling us to obtain about seven measurements per day for each of our 15 in-situ probes in the soil and tree xylem. While the labelling induced an abrupt step pulse in the soil water isotopic signature, it took seven to ten days until the isotopic signatures at the trees' stem bases reached their peak label concentrations and it took about 14 days until the isotopic signatures at 8 m stem height levelled off around the same values. During the experiment, we observed the effects of several rain events and dry periods on the xylem water isotopic signatures, which fluctuated between the measured isotopic signatures observed in the upper and lower soil horizons. In order to explain our observations, we combined an already existing root water uptake (RWU) model with a newly developed approach to simulate the propagation of isotopic signatures from the root tips to the stem base and further up along the stem. The key to a proper simulation of the observed short term dynamics of xylem water isotopes, was accounting for sap flow velocities and the flow path length distribution within the root and stem xylem. Our modelling framework allowed us to identify parameter values that relate to root depth, horizontal root distribution and wilting point. The insights gained from this study can help to improve the representation of stable water isotopes in trees within ecohydrological models and the prediction of transit time distribution and water age of transpiration fluxes.

Quantitative chemical analysis of airborne particulate matter (PM) is vital for the understanding of health effects in indoor and outdoor environments, as well as for enforcing EU air quality regulations. Typically, airborne particles are sampled over long time periods on filters, followed by lab-based analysis, e.g., with inductively coupled plasma mass spectrometry (ICP-MS). During the EURAMET EMPIR AEROMET project, cascade impactor aerosol sampling is combined for the first time with on-site total reflection X-ray fluorescence (TXRF) spectroscopy to develop a tool for quantifying particle element compositions within short time intervals and even on-site. This makes variations of aerosol chemistry observable with time resolution only a few hours and with good size resolution in the PM10 range. The study investigates the proof of principles of this methodological approach. Acrylic discs and silicon wafers are shown to be suitable impactor carriers with sufficiently smooth and clean surfaces, and a non-destructive elemental mass concentration measurement with a lower limit of detection around 10 pg/m3 could be achieved. We demonstrate the traceability of field TXRF measurements to a radiometrically calibrated TXRF reference, and the results from both analytical methods correspond satisfactorily.

Superhydrophobic surfaces possess susceptibility towards mechanical and chemical damages as well as oil fouling, which limits their widespread use in practical applications. Here, we demonstrate a straightforward approach to fabricate tunable bulk material with robust and renewable superhydrophobicity by in-situ loading of interconnected surface-wrinkled microparticles. The bulk material shows mechanochemically robust superhydrophobicity across its whole 3D volume, features renewable superhydrophobicity after extremely chemical corrosion, and could regenerate its water repellency after oil contamination. The bulk material also features ultrahigh efficiency (~98%) in oil-water mixtures separation, due to its selective oil absorption capability from water. Notably, the mechanical performances, microstructures and density of the bulk material can be adjusted on demand by simply changing the amount of loaded microparticles. Compared to the pristine commercial melamine-formaldehyde based porous substrate (MFPS), the achieved bulk material shows up to ~230 folds increase in Young’s modulus, ~145 folds increase in flexure stress and ~25 folds increase in tensile stress. This strategy features great potential for designing lightweight structural materials with robust waterproof functionality as well as materials with efficient oil recovery capability from wastewater.