Preparing super-hydrophobic surfaces with additive manufacturing (AM) and multi-step processes improves corrosion resistance of Al alloys. But the incorporation of dissimilar metals accelerates ...matrix corrosion, additive polymers cannot offer a long-term structural stability, and multi-step methods are complicated and costly. Hereon, stable micro-craters and nano-terraces on AA5052 sheet with enhanced water repellence and durable corrosion resistance are fabricated via low-cost subtractive manufacturing (SM) strategy. After fluoridation process, as-fabricated hierarchical structures possess highlighted self-cleaning and anti-adhesion capabilities. The following electrochemical test shows that the resultant surface effectively acts as a barrier against seawater infiltration suggesting superior anti-corrosion capacity. Meanwhile, the bacterial colony count test shows that the surface also possesses excellent resistance to microbiological adhesion. Such economic, efficient and environmental SM process is of great potential in fabricating multifunctional Al alloys with durable anti-corrosion, super-hydrophobic and bacteriostatic behaviors.
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•One-step electron discharge machining of stable hierarchical micro-nano structures is achieved.•The machined surface shows enhanced water-repellent, self-cleaning and anti-adhesion behaviors.•The surface acts as a durable barrier against seawater corrosion and bacteria adhesion.•Anti-corrosion mechanisms of various wetting states are systematically investigated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•A mechanically robust SLIPS with unique ‘corn-like’ structures was successfully acquired by a facile spraying method.•The SHC substrate for SLIPS could maintain superhydrophobicity ...after 200 harsh rubbing friction cycles.•Covalent Ti-O-Si bond and hydrogen bonds among polymers and fillers contributed to enhanced interfacial interactions.•The SLIPS exhibited outstanding mechanical durability, hot water repellence and chemical stability.
Poor mechanical stability and unstable oil layer of slippery liquid infused porous surface (SLIPS) are urgent issues to be tackled for its long-serving life. Herein, a pre-oil-infused mechanically robust hybrid organic/inorganic superhydrophobic coating (SHC) for SLIPS with prolonged longevity was acquired through concerted elaborate design of both micro-nano structures and chemical interactions. Abundant deposition of TiO2 on many stacked attapulgite (APT) nanorods because of covalent bond Ti-O-Si and hydrogen bond contributed to unique biomimetic ‘corn-like’ structures in SHC. The hydroxyl groups on TiO2 surface could also interact with crosslinked polymers PES (polyethersulfone) and PVDF-HFP (poly-vinylidene fluoride-co-hexafluoropropylene) via hydrogen bonds. Because of these strengthened mutual interfacial interactions, these ‘corn-like’ structures are thereby aggregated tightly together to form affluent and vigorous hierarchical nestle-like structures in SHC which not only exhibited robust superhydrophobicity but also provided sufficient capillary length to stabilize oil. The superhydrophobic substrate for SLIPS could withstand 200 cycles harsh Taber rubbing test (Loading = 250 kPa) and still maintained superhydrophobicity. The as-prepared SLIPS demonstrated outstanding 85 ℃ hot water repellence, high shear force stability (4000 rpm/min) and strong acid/alkali resistance owing to excellent oil-locking ability. This study represented a milestone for designing sturdy SLIPS for potential engineering applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•A 3D-printed biomimetic superhydrophobic surface with petal-like microstructures is proposed.•Parameters of microstructure array are optimized to achieve high bearing capacity.•Sharp ...edge effect combining with the arc curve effect is responsible for the super repellence property.•Applications of the optimized petal-like microstructured surface are studied.
Recently, bioinspired mushroom or reentrant mushroom microstructures have attracted intersts of researchers for their amazing water superrepellence property. However, basic principles of exquisite microstructures design for improving water repellence are still lacking. This paper reports a novel 3D-printed biomimetic superhydrophobic surface with petal-like microstructures inspired by the droplet pinning effect of nepenthes peristome. Then, parameters such as petal number, petal proportion and spacing distance are studied and optimized to improve water repellence, which is evaluated according to droplet bearing capacity. The results show that when the petal number is 4, the spacing distance is 100 μm, and the petal proportion is 50%, the petal-like structured surface achieves its maximum droplet bearing capacity. Comparing with the common mushroom microstructures, the maximum increase rate in bearing capacity is 58.3% for the optimized petal-like microstructures. Corresponding mechanism analysis attributes such superrepellence property to the sharp edge effect and the arch curve effect. Furthermore, the excellent water repellence enables the petal-like microstructured surface to be used for water droplets manipulation, oil-water separation, and captured-air drag reduction.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•PDMS-based coatings for deicing were prepared with wide-ranging properties.•Shear stresses developed on elastomeric surfaces allow to decrease ice adhesion strength.•Impact of the ...elasticity on ice adhesion is more noticeable under shear forces.•Impact of the hydrophobicity on ice adhesion is more noticeable under tensile forces.•Proper balance between surface and bulk properties leads to super low ice-adhesion.
Ice adhesion to rigid materials is reduced with low energy surfaces of high receding contact angles. However, their adhesion strength values are above the threshold value to be considered as icephobic materials. Surface deformability is a promising route to further reduce ice adhesion.
In this work, we prepared elastomer surfaces with a wide range of elastic moduli and hydrophobicity degree and we measured their ice adhesion strength. Moreover, we also explored the deicing performance of oil-infused elastomeric surfaces. The ice adhesion was characterized by two detachment modes: tensile and shear.
The variety of elastomeric surfaces allowed us to simultaneously analyze the ice adhesion dependence with deformability and contact angle hysteresis. We found that the impact of these properties depends on the detachment mode, being deformability more important in shear mode and hydrophobicity more relevant in tensile mode. In addition, oil infusion further reduces ice adhesion due to the interfacial slippage. From an optimal balance between deformability and hydrophobicity, we were able to identify surfaces with super-low ice adhesion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•A simple method to functionalize CFRP surface by using picosecond laser direct writing and fluoroalkylsilane immersion is proposed.•The functionalized CFRP surface possesses ...excellent water-repellence, self-cleaning and anti-icing properties.•The non-wetting CFRP surface shows remarkable tolerance towards low/high temperature exposure, falling sand abrasion and aqueous solutions invasion.
Carbon fiber reinforced polymer (CFRP) composites are widely used in various industry fields due to their high strength and stiffness. However, their intrinsic hydrophilicity makes the surface easily be wetted by water, which sometimes limits their practical applications. In this paper, we present a simple method to functionalize CFRP surface by using picosecond laser direct writing and fluoroalkylsilane immersion, through which micro/nanostructures and low surface energy are created on CFRP surface. The functionalized surface possesses static water contact angle >150° and rolling-off angle <10°, and impinged water droplet can easily rebound from the surface, showing excellent water-repellence. The non-wetting surface shows remarkable tolerance towards low/high temperature exposure, falling sand abrasion and aqueous solutions invasion. The superhydrophobicity impart CFRP surface Lotus-like self-cleaning property. Additionally, the functionalized CFRP surface shows outstanding anti-icing capacity compared with the original surface. Our results offer insights into the design of functional CFRP surface and might improve the application prospects of CFRP in some complex conditions like dusty, rainy and cold environments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Soil water-content (SWC) variability in forest ecosystems is affected by complex interactions between climate, topography, forest structure and soil factors. However, detailed studies taking into ...account the combined effects of these factors are scarce. This study's main aims were to examine the control that throughfall exerts on local spatial variation of near-surface soil water-content and to combine this information with forest structure and soil characteristics, in order to analyze all their effects together. Two stands located in the Vallcebre Research Catchments (NE Spain) were studied: one dominated by Quercus pubescens and the other by Pinus sylvestris. Throughfall and the related shallow SWC were monitored in each plot in 20 selected locations. The main characteristics of the nearest tree and soil parameters were also measured. The results indicated that mean SWC increment at the rainfall event scale showed a strong linear relationship with mean throughfall amount in both forest plots. The % of locations with SWC increments increased in a similar way to throughfall amount in both forest plots. The analyses considering all the effects together indicated again that throughfall had a significant positive effect in both forest plots, while soil litter depth showed a significant negative effect for the oak plot but lower statistical significance for the pine plot, showing a comparable –although more erratic– influence of the organic forest floor for this plot. These results, together with lower responses of SWC to throughfall than expected in rainfall events characterized by low preceding soil water-condition and high rainfall intensity, suggest that litter layer is playing an important role in controlling the soil water-content dynamics. The biometric characteristics of the nearest trees showed significant but very weak relationships with soil water-content increment, suggesting that stemflow and throughfall may act at lower distances from tree trunk than those presented in our study.
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•Soil water is affected by climate, topography, forest and soil factors.•Throughfall and related soil water were monitored in two forests at the plot scale.•Soil parameters and tree biometric were also measured.•Soil water responses were affected by throughfall depth.•Litter thickness showed a significant negative effect.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The impregnability of Portuguese maritime pine (Pinus pinaster Ait.) subjected to microwave (MW) drying was tested, and the hydrophobicity, anti-swelling efficiency (ASE), and water repellence ...efficiency (WRE) were evaluated. Small wood heartwood samples of Portuguese maritime pine and two distinct MW treatment settings were employed. The levels of ASE and WRE of the wood elements were evaluated throughout four cycles of drying in an oven and soaking in water. Because of MW applied energy, the wood pine samples were satisfactorily impregnated with the preservative product. Regarding the absolutely dry densities of the samples, very subtle reductions were measured, and they were statistically equivalent to the average density of the non-MW-treated group. Slight improvements were identified in the WRE values of wood samples dried in the microwave. In terms of ASE, both MW-treated groups had a statistically significant increase. The MW treatment decreased the volumetric swelling of the maritime pine wood specimens. Hence, this study raises new insights and previously unexplored paths that can contribute to the expansion and greater application of MW technology in maritime pine and other species.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A simple method to fabricate water‐repellent low‐hysteresis surfaces on various substrate materials based on impregnation with silicone oil is demonstrated. The thickness of the lubrication film has ...negligible influence on the roll‐off velocity which is determined by the film viscosity. As possible application thermocapillary transport of water droplets along such surfaces is shown. Corresponding experiments indicate that it is the motion relative to the lubricating film and not the film motion itself that dominates droplet transport.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Landscape sensitivity is a concept referring to the likelihood that changes in land use may affect in an irreversible way physical and chemical soil properties of the concerned landscape. The ...objective of this study is to quantitatively assess the sensitivity of the southern Alpine soil landscape regarding land use change-induced perturbations. Alpine soil landscapes can be considered as particularly sensitive to land use changes because their effects tend to be enhanced by frequent extreme climatic and topographic conditions as well as intense geomorphologic activity. In detail, the following soil key properties for soil vulnerability were analysed: (i) soil texture, (ii) bulk density, (iii) soil organic carbon (SOC), (iv) saturated hydraulic conductivity (Ksat), (v) aggregate stability and (vi) soil water repellency (SWR). The study area is characterized by a steep, east-west oriented valley, strongly anthropized in the last centuries followed by a progressive abandonment. This area is particularly suitable due to constant lithological conditions, extreme topographic and climatic conditions as well as historic land use changes. The analysis of land use change effects on soil properties were performed through a linear mixed model approach due to the nested structure of the data. Our results show a generally high stability of the assessed soils in terms of aggregate stability and noteworthy thick soils. The former is remarkable, since aggregate stability, which is commonly used for detecting land use-induced changes in soil erosion susceptibility, was always comparably high irrespective of land use. The stability of the soils is mainly related to a high amount of soil organic matter favouring the formation of stable soil aggregates, decreasing soil erodibility and hence, reducing soil loss by erosion. However, the most sensitive soil property to land use change was SWR that is partly influenced by the amount of soil organic carbon and probably by the quality and composition of SOM.
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•Soil of the Onsernone valley shows high aggregate stability irrespective of land use.•High aggregate stability is caused by high amounts of SOC.•Land use changes affect SOC but do not impact aggregate stability.•Pastures and abandoned terraces are most susceptible to Hortonian surface runoff.•Soil water repellence was the most sensitive parameter to land use changes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Multifarious electron transport layers (ETLs), especially fullerene derivatives, have been applied in organic–inorganic hybrid perovskite (OIHP) devices owing to their superior optoelectronic ...properties. However, a PCBM Lewis acid molecule can only passivate the iodine-rich defect sites, which cannot solve the problem of uncoordinated Pb2+ and water oxygen erosion due to the high volatility of halide I– and the hydrophilicity of organic cation MA+. Herein, we introduce a Lewis base, TBA-Azo with an electron-donating Azo moiety, and hydrophobic long alkyl chains into the PCBM layer to form a multifunctional bulk-mixed electron transport layer (MBE). PCBM of MBE can combine with iodine-rich trap sites at the surface and grain boundaries of perovskite. TBA-Azo molecules of MBE can passivate uncoordinated Pb2+ by forming Lewis adducts and isolate water/oxygen at the perovskite surface with hydrophobic alkyl chains. It results in a decrease of trap densities with 1 order of magnitude, effectively inhibiting both bimolecular and trap-induced recombination and thus elongating the carrier lifetime. The passivation of MBE can effectively improve the open-circuit voltage from 1.05 to 1.10 V. Furthermore, three long carbon chain structures of TBA-Azo in MBE can improve the water-resistant ability of OIHP devices, which can maintain 90% of the original PCE after 500 h at the humidity of 50 ± 10%. We believe that the MBE with multifunctional defect passivation provides a strategy for simultaneously achieving high-performance and high-stability OIHP optoelectronic devices.
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IJS, KILJ, NUK, PNG, UL, UM
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