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Super-hydrophobic and liquid-repellent surfaces can be characterized experimentally in tensile adhesion experiments with the force (FAdh) required to detach a droplet from such surfaces, but analytical expressions that relate FAdh to the surface energy, w, are still missing. In this work, we derive analytical expressions for FAdh between droplets of radius r and super-hydrophobic surfaces on which the contact angle is greater than 150°. By applying the general condition for the onset of instability in different mechanical configurations, we find FAdh = −πwr and FAdh ≈ −(4/5)πwr, for the fixed-force and fixed-grip configurations, respectively, as well as other expressions that depend on the ratio of the spring constant of a generic force measuring apparatus to the surface tension of the liquid composing the droplet. These expressions open the possibility of retrieving w or, equivalently, the receding contact angle, by measuring FAdh on these systems. [ABSTRACT FROM AUTHOR]

The wettability of SiO2 surfaces, crucial for understanding the phase transition processes of water, remains a topic of significant controversy in the literature due to uncertainties in experiments. Molecular dynamics (MD) simulations offer a promising avenue for elucidating these complexities, yet studies specifically addressing water contact angles on hydrophilic and hydrophobic SiO2 surfaces at sub-ambient temperatures are notably absent. In this study, we experimentally measured water contact angles of hydrophilic and hydrophobic SiO2 surfaces at ambient temperature and employed MD to investigate water contact angles on Q3, Q3/Q4, and Q4 SiO2 surfaces across temperatures ranging from 220 to 300 K. We investigated the effects of the distribution of hydroxyl groups, droplet size, and hydroxyl density and found that the hydroxyl density had the largest impact on contact angle. Moreover, hydrogen bond analysis uncovered enhanced water affinities of Q3 and Q3/Q4 SiO2 surfaces at lower temperatures, and the spreading rate of precursor films reduced with decreasing temperature. This comprehensive study sheds light on the intricate interaction between surface properties and water behavior, promoting our understanding of the wettability of SiO2 surfaces. [ABSTRACT FROM AUTHOR]

In 2012, the molecular structure of a new, broad class of ice-binding proteins, classified as "domain of unknown function" (DUF) 3494, was described for the first time. These proteins have a common tertiary structure and are characterized by a very wide spectrum of antifreeze activity (from weakly active to hyperactive). The ice-binding surface (IBS) region of these molecules differs significantly in its structure from the IBS of previously known antifreeze proteins (AFPs), showing a complete lack of regularity and high hydrophilicity. The presence of a regular, repeating structural motif in the IBS region of hitherto known AFP molecules, combined with the hydrophobic nature of this surface, promotes the formation of an ice-like ordering of the solvation water layer and, as a result, facilitates the process of transformation of this water layer into ice. It is, therefore, surprising that the newly discovered DUF3494 class of proteins clearly breaks out of this characteristic. In this paper, using molecular dynamics simulations, we analyze the solvation water structure of the IBS region of both DUF3494 family molecules and AFPs. As we show, although the IBS of DUF3494 molecules does not form an ice-like water structure in the solvation layer, this is compensated by the formation of the equivalent of "anchored clathrate water," in the form of a relatively large number of water molecules bound to the surface of the protein molecule and providing potential binding sites for it to the ice surface. [ABSTRACT FROM AUTHOR]

Thermophoresis, or thermodiffusion, is becoming a more popular method for investigating the interactions between proteins and ligands due to its high sensitivity to the interactions between solutes and water. Despite its growing use, the intricate mechanisms behind thermodiffusion remain unclear. This gap in knowledge stems from the complexities of thermodiffusion in solvents that have specific interactions as well as the intricate nature of systems that include many components with both non-ionic and ionic groups. To deepen our understanding, we reduce complexity by conducting systematic studies on aqueous salt solutions. In this work, we focused on how guanidinium salt solutions behave in a temperature gradient, using thermal diffusion forced Rayleigh scattering experiments at temperatures ranging from 15 to 35 °C. We looked at the thermodiffusive behavior of four guanidinium salts (thiocyanate, iodide, chloride, and carbonate) in solutions with concentrations ranging from 1 to 3 mol/kg. The guanidinium cation is disk-shaped and is characterized by flat hydrophobic surfaces and three amine groups, which enable directional hydrogen bonding along the edges. We compare our results to the behavior of salts with spherical cations, such as sodium, potassium, and lithium. Our discussions are framed around how different salts are solvated, specifically in the context of the Hofmeister series, which ranks ions based on their effects on the solvation of proteins. [ABSTRACT FROM AUTHOR]

A pillared-layered metal–organic framework (MOF) {[Zn2(atpt)2(bpBTD)]·solv}n (1), where H2atpt = 2-aminoterephthalic acid and bpBTD = bis(pyridin-4-yl)benzothiadiazole, showing a pcu net topology with double interpenetration was successfully constructed. Thermally activated 1 possessed free voids of 15.3% and repeatedly exhibited two-step CO2 adsorption isotherms over three runs, with uptakes of 138.8 cm3 g−1 STP at 195 K and P/P0 = 1. Through a ligand replacement exfoliation approach, metal–organic framework (MOF) nanosheets {[Zn2(atpt)2(4-picoline)2]}n (1-ns) with a 2D sql net topology were obtained by immersing 1 in 4-picoline. Characterization of 1-ns was achieved using energy-dispersive X-ray spectroscopy (EDS), infrared (IR) spectroscopy, X-ray powder diffraction (XRPD) patterns, and elemental analyses (EA) as well as scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Photoluminescence spectra showed that 1 and 1-ns both emitted blue-light fluorescence in H2O. In addition, measurements of water contact angles indicated that 1 is highly hydrophilic, while 1-ns shows poor hydrophilicity compared with 1. The double-sided hydrophobic surfaces of 1-ns allowed oil (dichloromethane) but not water to pass through, making it a good candidate for oil/water separation. Electrochemical measurement revealed that the 2D metal–organic nanosheet 1-ns modified glassy carbon electrode (1-ns/GCE) possessed much better electron transfer ability than the 3D pillared-layer framework 1 modified glassy carbon electrode (1/GCE), and thus improves the electrochemical performance and sensitivity. [ABSTRACT FROM AUTHOR]

Excessive vascularization during tracheal in-stent restenosis (TISR) is a significant but frequently overlooked issue. We developed an anti-inflammatory coupled anti-angiogenic airway stent (PAGL) incorporating anlotinib hydrochloride and silver nanoparticles using advanced electrospinning technology. PAGL exhibited hydrophobic surface properties, exceptional mechanical strength, and appropriate drug-release kinetics. Moreover, it demonstrated a remarkable eradication effect against methicillin-resistant Staphylococcus aureus. It also displayed anti-proliferative and anti-angiogenic properties on human umbilical vein endothelial cells and lung fibroblasts. PAGL was implanted into the tracheae of New Zealand rabbits to evaluate its efficacy in inhibiting bacterial infection, suppressing the inflammatory response, reducing angiogenesis, and attenuating excessive fibroblast activation. RNA sequencing analysis revealed a significant downregulation of genes associated with fibrosis, intimal hyperplasia, and cell migration following PAGL treatment. This study provides insight into the development of airway stents that target angiogenesis and inflammation to address problems associated with TISR effectively and have the potential for clinical translation. [ABSTRACT FROM AUTHOR]

Condensation is a vital process integral to numerous industrial applications. Enhancing condensation efficiency through dropwise condensation on hydrophobic surfaces is well-documented. However, no surfaces have been able to repel liquids with extremely low surface tension, such as fluorinated solvents, during condensation, as they nucleate and completely wet even the most hydrophobic interfaces. Here, we introduce a surface functionalization methodology that enables dropwise condensation of fluorinated refrigerants. This approach, compatible with various substrates, combines low contact angle hysteresis Parylene-C with low surface energy silane (P-HFDS) using a highly scalable atmospheric vapor phase deposition technique. Our experimental results demonstrate that the omniphobic P-HFDS coating facilitates dropwise condensation of both natural refrigerants (water, ethanol, hexane, pentane) and synthetic low-global-warming-potential refrigerants (HCFO R1233zd(E) and HFO R1336mzz(Z)) with surface tension as low as 14.6 mN m−1 at 25°C. The P-HFDS coating improves condensation heat transfer coefficients by 274%, 347%, 636%, and 688% for ethanol, hexane, pentane, and R1233zd(E), respectively, compared to filmwise condensation on uncoated metal surfaces. Additionally, the coating demonstrates long-term durability, sustaining steady dropwise condensation for 170 days without apparent degradation. This work pioneers stable dropwise condensation of multiple refrigerants on a structure-less surface, offering a durable, substrate-independent, and scalable solution for low surface energy coatings. Achieving long-term sustainable dropwise condensation of low-surface-tension refrigerants has been a decades-long challenge. The authors introduce a coating that facilitates dropwise condensation of fluorinated refrigerants, significantly improving heat transfer and showcasing durability across various substrates. [ABSTRACT FROM AUTHOR]

In maximally Ca2+-activated demembranated fibres from the mammalian skeletal muscle, the depression of the force by lowering the temperature below the physiological level (~35 °C) is explained by the reduction of force in the myosin motor. Instead, cooling is reported to not affect the force per motor in Ca2+-activated cardiac trabeculae from the rat ventricle. Here, the mechanism of the cardiac performance depression by cooling is reinvestigated with fast sarcomere-level mechanics. We determine the changes in the half-sarcomere compliance of maximally Ca2+-activated demembranated rat trabeculae in the range of temperatures of 10–30 °C and analyse the data in terms of a simplified mechanical model of the half-sarcomere to extract the contribution of myofilaments and myosin motors. We find that the changes in the ensemble force are due to changes in the force per motor, while the fraction of actin-attached motors remains constant independent of temperature. The results demonstrate that in the cardiac myosin, as in the skeletal muscle myosin, the force-generating transition is endothermic. The underlying large heat absorption indicates the interaction of extended hydrophobic surfaces within the myosin motor, like those suggested by the crystallographic model of the working stroke. [ABSTRACT FROM AUTHOR]

Hernia repair is the most common surgical operation applied worldwide. Mesh prostheses are used to support weakened or damaged tissue to decrease the risk of hernia recurrence. However, the patches currently used in clinic applications have significant short-term and long-term risks. This study aimed to design, produce, and characterize a three-layered semi-resorbable composite hernia mesh using the electrospinning technique, where the upper layer (parietal side) was made of non-resorbable polypropylene (PP-Cl) fibers, the partially resorbable middle layer was made of PP-Cl and polycaprolactone (PCL) fibers, and the fully resorbable lower layer (visceral side) was made of H. perforatum oil-loaded polyethylene glycol (PEG) fibers. The extracellular matrix-like fibrous structure of the patches provided low density and high porosity, minimizing the risk of long-term foreign body reactions, and the hydrophilic/hydrophobic character of the surfaces and the detected swelling rates supported biocompatibility. The patches exhibited mechanical properties comparable to commercially available products. Controlled release of therapeutic oil could be achieved from the oil-integrated patches due to the dissolution of PEG in the acute process. In vitro cell culture studies with the L929 mouse fibroblast cell line revealed that the meshes do not have a cytotoxic nor a biomaterial-induced necrotic effect that will induce apoptosis of the cells. The visceral side of the meshes exhibited non-adherence of cell-like structures to the surface due to the dissolution of PEG. The composite hernia patches were concluded to reduce the risk of adhering to internal organs in the hernia area, have the potential to be used in in vivo biomedical applications, and will support the search for an ideal hernia mesh that can be used in the treatment of abdominal hernias. [ABSTRACT FROM AUTHOR]

Gypsum (CaSO4·2H2O) plays a critical role in numerous natural and industrial processes. Nevertheless, the underlying mechanisms governing the formation of gypsum crystals on surfaces with diverse chemical properties remain poorly understood due to a lack of sufficient temporal-spatial resolution. Herein, we use in situ microscopy to investigate the real-time gypsum nucleation on self-assembled monolayers (SAMs) terminated with −CH3, −hybrid (a combination of NH2 and COOH), −COOH, −SO3, −NH3, and −OH functional groups. We report that the rate of gypsum formation is regulated by the surface functional groups and hydrophobicity, in the order of −CH3 > −hybrid > −COOH > −SO3 ≈ − NH3 > − OH. Results based on classical nucleation theory and molecular dynamics simulations reveal that nucleation pathways for hydrophilic surfaces involve surface-induced nucleation, with ion adsorption sites (i.e., functional groups) serving as anchors to facilitate the growth of vertically oriented clusters. Conversely, hydrophobic surfaces involve bulk nucleation with ions near the surface that coalesce into larger horizontal clusters. These findings provide new insights into the spatial and temporal characteristics of gypsum formation on various surfaces and highlight the significance of surface functional groups and hydrophobicity in governing gypsum formation mechanisms, while also acknowledging the possibility of alternative nucleation pathways due to the limitations of experimental techniques. This work demonstrates different gypsum nucleation pathways on hydrophilic and hydrophobic surfaces through in situ microscopy and molecular dynamics simulations. [ABSTRACT FROM AUTHOR]

Copyright of Gold (1001-1277) is the property of Gold Magazine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Design of TiO2 photocatalyst and mesoporous silica composites were carried out for application to water purification. Two different types of precursors (titanium ammonium oxalate and ammonium hexafluorotitanate) for anchoring of TiO2 on mesoporous silica were adopted for comparative studies to show the roles of chemical constituents in both precursors. In the utilization of ammonium hexafluorotitanate, hydrophobic nature on the surface of mesoporous silica as well as the high crystallinity and visible light absorption performance of TiO2 were achieved by the co-existence of fluorine and nitrogen during the decomposition of precursors to TiO2 at elevated temperature. Based on these fascinating functions of composite photocatalyst, good photocatalytic activity was realized in the degradation of phenol in water under UV light (λ > 290 nm) irradiation. This composite photocatalyst also exhibited photocatalytic activity even under visible light (λ > 420 nm) irradiation. [ABSTRACT FROM AUTHOR]

To improve the wound dressing characteristics of bacterial cellulose-based materials and address the issue of asymmetric wound dressing with one hydrophilic side and another hydrophobic side, this study developed a new concept for the fabrication of an asymmetric wettable and antibacterial wound dressing by selective drop coating of stearic acid-modified ZnO, chitosan, and AgNPs to form a dot pattern on both surfaces of a bacterial cellulose–alginate composite (BA-ZnS/Ch/Ag). The coated surface was hydrophobic, with a WCA of 150° due to the formation of a low surface energy zinc stearate (C17H35COO)2Zn) monolayer on the ZnO particles and a high degree of hierarchical roughness. The asymmetric wettable BA-ZnS/Ch/Ag wound dressing maintained good water absorptivity (swelling rate 417%) and natural breathability (water vapor transmission rate 792 g.m−2 day−1) of the superhydrophilic bacterial cellulose-alginate composite that consisted of dense outer surfaces and porous inner layers and simultaneously possessed the superhydrophobic property of the coating area that can reduce the risk of infection from external fluids and improve the blood repellency and anti-adhesion properties. The BA-ZnS/Ch/Ag wound dressing showed good antibacterial activity against S. aureus and E. coli and non-toxicity to human keratinocyte immortal cells (HaCaT), making it suitable for clinical applications. [ABSTRACT FROM AUTHOR]

Fabrics with directional water transport performance have attracted considerable attention in daily life. They are in high demand, owing to their ability to transport sweat away from the skin to improve personal comfort. However, the fabrication of such materials has still remained a critical task. This article reports a nonwoven with the directional water transport function, achieved using a synergistic combination of a microstructure and a wettability gradient. The three-step fabrication strategy involves needling bonding of Y cross-section polyamide fiber webs with two needling densities (30 and 190 needle/cm2), followed by single-sided spraying of polydopamine–silicon carbide powder–polyethyleneimine dispersion and a fluoride-free hydrophobic agent. Using fiber webs with different needling densities endows the nonwoven fabric with a differential capillary effect, enhancing the directional water transport property. The unique microstructure achieves the directional water transport property by improving permeability at lower needling densities and hindering transport through a denser needling density in the reverse direction. At the same time, the wetting gradient effect promotes water transfer from the hydrophobic surface to the hydrophilic surface. The successful preparation of these interesting directional water transport materials offers new insights into the role of fibrous materials, the needling density of nonwovens, and the development of highly comfortable moisture-wicking textiles. [ABSTRACT FROM AUTHOR]

Engineering the microenvironment of electrode surface is one of the effective means to tune the reaction pathways in CO2RR. In this work, we prepared copper nanofibers with conductive polypyrrole coating by polymerization of pyrrole using polyvinyl pyrrolidone (PVP) as template. As a result, the obtained copper nanofibers Cu/Cu2+1O/SHNC, exhibited a superhydrophobic surface, which demonstrated very high selectivity for ethanol with a Faraday efficiency (FE) of 66.5 % at −1.1 V vs reversible hydrogen electrode (RHE) in flow cell. However, the catalyst Cu/Cu2+1O/NC, which was prepared under the same conditions but without PVP, possessed a hydrophobic surface and exhibited high selectivity towards ethylene at the given potentials. The mechanism for switch of reaction pathways from ethylene to ethanol in CO2RR was studied. Incorporating pyrrolidone groups into the polymer coating results in the formation of a superhydrophobic surface. This surface weakens the hydrogen bonding interaction between interfacial water molecules and facilitates the transfer of CO2, thereby enhancing the local CO2/H2O ratio. The high coverage of *CO promotes the coupling of *CO and *CHO to form C2 intermediates, and reduces the reaction energy for the formation of *CHCHOH (ethanol path) at the interface. This ensures that the reaction pathway is directed towards ethanol. [ABSTRACT FROM AUTHOR]

Vertical egg distributions are needed knowledge for understanding exposure to physical forcing, predation pressure, and modelling initial transport from the spawning areas. Egg density and size are the biotic factors determining vertical distributions while the ambient salinity and turbulent mixing are the physical factors contributing to their vertical distributions. Egg buoyancies and densities of Atlantic cod (Gadus morhua) have been extensively studied, while limited information on haddock (Melanogrammus aeglefinus) egg density is available. This is the first comprehensive study on haddock egg densities in Norwegian waters. Eggs were collected from pairs of spawning fish caught at the coast of western Norway and inserted into a density gradient column where density was measured. The haddock eggs were neutrally buoyant at salinities ranging from 28.5 to 31. The density changed during egg development, and the results from the measurements were used to model the vertical distribution of the eggs. The simulations showed that the changes in buoyancy substantially affected vertical distributions. A comparison to previously published data on cod eggs showed that haddock eggs are considerably more buoyant than the cod eggs and are—particularly during calm wind conditions—confined to the surface layer to a larger extent than the cod eggs. The more buoyant attribute of the haddock eggs, together with the lipophilic surface of the egg membrane, is suggested to make haddock eggs more vulnerable to buoyant pollutants, like hydrocarbons. [ABSTRACT FROM AUTHOR]

Copyright of Progress in Photovoltaics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Brachytherapy (BT) is routinely used in the treatment of various cancers. Current BT relies on the placement of large sources of radioactivity at the tumor site, requiring applicators that may cause local traumas and lesions. Further, they suffer from inflexibility in where they can be placed and some sources reside permanently in the body, causing potential long-term discomfort. These issues can be circumvented through injectable sources, prepared as biodegradable materials containing radionuclides that form solid seeds after administration. The level of radioactivity contained in such seeds must be sufficient to achieve substantial local irradiation. In this report, we investigate two different strategies for biodegradable BT seeds. Results: The first strategy entails injectable seeds based on 103Pd-labeled palladium-gold alloy nanoparticles ([103Pd]PdAuNPs). These were prepared by combining [103Pd]PdH2Cl4 and AuHCl4, followed by lipophilic surface coating and dispersed in lactose octaisobutyrate and ethanol (LOIB:EtOH), in overall radiochemical yield (RCY) of 83%. With the second strategy, [103Pd]Pd-SSIB was prepared by conjugating the [16]aneS4 chelator with lipophilic sucrose septaisobutyrate (SSIB) followed by complexation with [103Pd]PdH2Cl4 (RCY = 99%) and mixed with LOIB:EtOH. [103Pd]Pd-SSIB was likewise formulated as injectable liquid forming seeds by mixing with LOIB. Both formulations reached activities of 1.0–1.5 GBq/mL and negligible release of radioactivity after injection of 100 µL (100–150 MBq) into aqueous buffer or mouse serum of less than 1% over one month. Conclusion: Both strategies for forming injectable BT seeds containing high 103Pd activity resulted in high radiolabeling yields, high activity per seed, and high activity retention. We consider both strategies suitable for BT, with the preferable strategy using a [16]aneS4 chelator due to its higher biodegradability. [ABSTRACT FROM AUTHOR]

The organophosphate (OP)‐hydrolyzing enzyme phosphotriesterase (PTE, variant L7ep‐3a) immobilized within a partially oxidized mesoporous silicon nanoparticle cage is synthesized and the catalytic performance of the enzyme@nanoparticle construct for hydrolysis of a simulant, dimethyl p‐nitrophenyl phosphate (DMNP), and the live nerve agent VX is benchmarked against the free enzyme. In a neutral aqueous buffer, the optimized construct shows a ≈2‐fold increase in the rate of DMNP turnover relative to the free enzyme. Enzyme@nanoparticles with more hydrophobic surface chemistry in the interior of the pores show lower catalytic activity, suggesting the importance of hydration of the pore interior on performance. The enzyme@nanoparticle construct is readily separated from the neutralized agent; the nanoparticle is found to retain DMNP hydrolysis activity through seven decontamination/recovery cycles. The nanoparticle cage stabilizes the enzyme against thermal denaturing and enzymatic (trypsin) degradation conditions relative to free enzyme. When incorporated into a topical gel formulation, the PTE‐loaded nanoparticles show high activity toward the nerve agent VX in an ex vivo rabbit skin model. In vitro acetylcholinesterase (AChE) assays in human blood show that the enzyme@nanoparticle construct decontaminates VX, preserving the biological function of AChE when exposed to an otherwise incapacitating dose. [ABSTRACT FROM AUTHOR]

The article "Coating thickness prediction for a viscous film on a rough plate" in the Journal of Fluid Mechanics presents a predictive model for determining liquid film thickness on a rough plate using a homogenization approach. The model considers slip and interface permeability terms that vary with the solid fraction of the rough surface, validated by experimental measurements showing decreased slip and permeability with increasing solid fraction. The study highlights the significance of solid fraction in determining slip and permeability values for rough surfaces, exploring the relationship between coating thickness, coating velocity, slip length, and interface permeability. Additionally, the document includes a list of related scientific articles covering topics such as fluid dynamics, porous media, surface interactions, and scientific computing algorithms, offering valuable insights into fluid-solid interactions across different contexts. [Extracted from the article]

In this paper, laser surface texturing (LST) has been used to create the circular and diamond shape texturing pattern on martensitic steel of grade SS410 to alter the various mechanical, surface, and tribological properties. The mechanical and surface characterizations have done on various shape-textured surfaces on SS410. Moreover, the slurry jet erosion test has performed on textured surfaces using a slurry erosion test rig. The hardness value of the various textured shape surface is higher than the others because mechanism of material removal for pattern is melting and evaporation, after applying an intense heat sudden cooling takes place. This might be altering the microstructure and enhances the hardness of the textured steel. The hardness value was the highest for circular-inward-textured case (HV0.3≈206) among all texturing. The tensile and flexural yield strength has marginally increased after texturing. The value of percentage elongation has marginally decreased after texturing. The modulus values for all the textured samples have enhanced as compared to untextured sample. Moreover, the modulus value of diamond-in textured samples are observed to be the highest i.e., ≈265GPa. The contact angles for all shapes of texturing patterns have greater values than untextured samples. All the textured surfaces show the hydrophobic and untextured surface as hydrophilic behavior. The outward textured surface has greater contact angle value (≈110°) as compared to others. The erosion resistance for the untextured samples have lesser among all textured samples, and the circular-in pattern has the highest erosion resistance. Because the erosion resistance is primarily depend on the hardness of the material, the plowing, microcutting lips, crater, and carbide pull-out type of wear mechanism has been identified using a scanning electron microscope. [ABSTRACT FROM AUTHOR]

The article "Dynamic hysteresis of an oscillatory contact line" in the Journal of Fluid Mechanics delves into the concept of dynamic hysteresis in oscillatory wetting, revealing a phase delay between contact angle changes and contact line speed. The research demonstrates that dynamic hysteresis can be adjusted by altering surface properties and is connected to static hysteresis. The study suggests new methods for forecasting dynamic hysteresis and stresses the significance of comprehending contact line dynamics in changing conditions. Additionally, the text examines the assessment of contact line friction coefficient in the context of dynamic hysteresis, presenting calculations for mechanical work and highlighting differences in dynamic hysteresis and friction coefficients on various surfaces. The study also addresses the limitations of current models and suggests improvements to enhance predictive accuracy for dynamic wetting behaviors. [Extracted from the article]

Micro- and nanorobots excel in navigating the intricate and often inaccessible areas of the human body, offering immense potential for applications such as disease diagnosis, precision drug delivery, detoxification, and minimally invasive surgery. Despite their promise, practical deployment faces hurdles, including achieving stable propulsion in complex in vivo biological environments, real-time imaging and localization through deep tissue, and precise remote control for targeted therapy and ensuring high therapeutic efficacy. To overcome these obstacles, we introduce a hydrogel-based, imaging-guided, bioresorbable acoustic microrobot (BAM) designed to navigate the human body with high stability. Constructed using two-photon polymerization, a BAM comprises magnetic nanoparticles and therapeutic agents integrated into its hydrogel matrix for precision control and drug delivery. The microrobot features an optimized surface chemistry with a hydrophobic inner layer to substantially enhance microbubble retention in biofluids with multiday functionality and a hydrophilic outer layer to minimize aggregation and promote timely degradation. The dual-opening bubble-trapping cavity design enables a BAM to maintain consistent and efficient acoustic propulsion across a range of biological fluids. Under focused ultrasound stimulation, the entrapped microbubbles oscillate and enhance the contrast for real-time ultrasound imaging, facilitating precise tracking and control of BAM movement through wireless magnetic navigation. Moreover, the hydrolysis-driven biodegradability of BAMs ensures its safe dissolution after treatment, posing no risk of long-term residual harm. Thorough in vitro and in vivo experimental evidence demonstrates the promising capabilities of BAMs in biomedical applications. This approach shows promise for advancing minimally invasive medical interventions and targeted therapeutic delivery. Editor's summary: Microrobots offer several opportunities in medicine for the diagnosis and treatment of various complications. However, there are several challenges related to their efficacy and ability to be detected in real time when deployed within the body. Han et al. have now developed bioresorbable acoustic microrobots that can be propelled acoustically and magnetically to tissues of interest and used for real-time ultrasound imaging and delivery of therapeutics. The gas-filled acoustic microrobots were used in vivo in a murine bladder tumor model and demonstrated the potential to support real-time imaging and delivery of anticancer drugs to the diseased tissue, resulting in the reduction in tumor size. —Amos Matsiko [ABSTRACT FROM AUTHOR]

In printed electronics, achieving precise deposition of conductive materials on challenging substrates like Teflon is critical. This study delves into dispense printing, a technique that offers precision and versatility for creating electronic patterns. The deposition of high‐viscosity silver flake inks on both hydrophobic surfaces is investigated, such as Teflon, and hydrophilic ones, highlighting the significant interplay between ink viscosity and substrate wettability. This interaction is key to controlling ink spreading, drying behavior, and, ultimately, printing success. Research explores the relationships between critical parameters such as nozzle height, dispense pressure, and print speed, aiming to enhance the quality and functionality of printed electronics. The printing process is analyzed through its distinct phases: extrusion from the nozzle, spreading on the substrate, and line shrinking during drying. This methodological approach allows one to pinpoint how each parameter specifically influences the printing outcome, particularly on challenging substrates like Teflon. By advancing the understanding of these dynamics, the study offers valuable theoretical insights and practical advancements for fabricating high‐quality, flexible electronics across diverse substrates. The findings underscore dispense printing's potential to meet the growing demand for flexible electronics. [ABSTRACT FROM AUTHOR]

The variable heavy chain fragments derived from camelid antibodies, called VHHs or nanobodies, have recently shown promise as high-affinity reagents. They offer higher stability compared to conventional antibodies and fragments thereof. Furthermore, their smaller size (~15–20 kDa) allows better targeting of molecules localized inside the cell and in crowded environments, like tissues and protein aggregates. Despite these advantages, nanobody clones screened using phage display can suffer from poor soluble expression, which we hypothesized is due to the presence of hydrophobic hotspots on their surface. In this work, we propose a novel, computationally guided workflow for screening and production of nanobody binders for optimized expression. After an initial round of phage display screens against our target (K-Ras), we modeled the lead candidates to generate spatial aggregation propensity (SAP) maps to highlight the hydrophobic hotspots with single amino acid resolution, which were subsequently used to guide mutagenesis of the binders for soluble expression. We followed two approaches to perform point hydrophilic mutations: (i) performing point hydrophilic mutations in the hydrophobic hotspots; (ii) combining point mutation resulting from a round of random mutagenesis that show favorable SAP scores. Both approaches led to a remarkable increase in soluble expression, which allowed production and characterization of their binding to their target (K-Ras) on soluble ELISA and biolayer interferometry. We observed that the latter approach resulted in clones with stronger binding affinity compared to the former approach. Our results emphasize the need to perform a round of random mutagenesis to identify point mutations, which can then be used in an in silico guided pipeline to identify the right combination of mutations for high soluble expression. [ABSTRACT FROM AUTHOR]

The development of hydrophobicity on polymer surfaces in mass production is one of the most critical challenges in the plastic industry. This paper deals with a novel combined hot embossing process in which femtosecond laser ablation is utilized to texture the embossing stamps. By controlling the process temperature and axial forces, the laser textures were transferred to polymer surfaces, successfully resulting in hydrophobicity. Four different polymers, including ABS, PP, PA, and PC, along with two different laser textures, namely ball and pyramid, were tested. The laser and hot embossing parameters under which the textures were transferred to the polymers are introduced. The critical micro- and nano-features of the transferred textures that resulted in high hydrophobic contact angles are also discussed. The results indicate that PP and ABS have higher contact angles, respectively, while under the given parameters, PA and PC did not exhibit hydrophobic surfaces. [ABSTRACT FROM AUTHOR]

The two‐dimensional (2‐D) Janus and amphiphilic molybdenum disulfide (MoS2) nanosheet with opposite optical activities on each side (amphichiral) is synthesized by modifying sandwich‐like bulk MoS2 with tannic acid and cholesterol through biphasic emulsion method. This new type of amphichiral Janus MoS2 nanosheet consists of a hydrophilic and positive optical activity tannic acid side as well as a hydrophobic and negative optical activity cholesterol side thereby characterized by circular dichroism. Surface‐directed orientational differentiation assemblies are performed for the as‐synthesized 2D material and are characterized by contact angle, infrared spectroscopy, X‐ray photoelectron, and circular dichroism spectroscopies. The amphiphilic nature of the materials is demonstrated by the pre‐organization of the nanosheets on either hydrophobic or hydrophilic surfaces, providing unprecedented properties of circular dichroism signal enhancement and wettability. Selective detachment of the surface organic groups (cholesterol and tannic acid fragments) is realized by matrix‐assisted laser desorption/ionisation ‐ time‐of‐flight (MALDI‐TOF) mass spectrometry, and the dual substrate release in tissue is detected by ex vivo mass spectrometry imaging. [ABSTRACT FROM AUTHOR]

Luminescent solar concentrators (LSCs) are highly valued in transparent photovoltaics for their versatility and adaptability as effective large‐area sunlight collectors. However, constructing LSCs as efficient, long‐term stable, and easily malleable power‐generating units still remains a challenge. Herein, high photostability, high photoluminescence quantum yield (ΦPL), and Stokes‐shifted emission are achieved in tetra(t‐butyl)rubrene/off‐stoichiometry thiol‐ene (TBRb/OSTE) hybrids by incorporating TBRb molecules into OSTE polymers. To demonstrate their potentials in LSCs, a luminescent solar concentrator integrated photovoltaics (LSCIPV) is created using a one‐step synthesis that combines the preparation of TBRb/OSTE hybrids, coupling with the silicon solar cell, and the encapsulation of both components. The LSCIPV demonstrates remarkable flexibility and the integration of an ethylene tetrafluoroethylene film contributes to a hydrophobic surface and antireflection effect, resulting in an external photon efficiency (ηext) of 4.9% and a power conversion efficiency of 1.04% for the 100 cm2 device. The LSCIPV exhibits good photostability over 800 h of UV light exposure. Monte Carlo ray‐tracing simulations indicate that an optimized TBRb‐based LSCIPV can potentially achieve an ηext of 1.3%, even for a large device with an area of 1 m2. [ABSTRACT FROM AUTHOR]

In recent years, the interest in structured hydrophobic surfaces has considerably grown, finding applications in many industrial fields, including aerospace, automotive, and biomedical. Three‐dimensional (3D) printing technology is a simple, rapid, and economic process to fabricate structured surfaces based on neat polymers and composite materials, allowing working with a wide variety of plastic materials. The manufactured surfaces show a roughness depending on the printing design and the printing resolution: this characteristic is ideal to achieve superhydrophobic properties. Furthermore, patterned surface structures can be printed by fused filament fabrication (FFF), so increasing the hydrophobic character of the samples; indeed, micro‐ and nanosurface structures are required to make a hydrophobic surface. In this study, 3D micropatterned textures of pillars were printed by FFF using polylactide (PLA) and polypropylene (PP) as polymer filaments and PLA/carbon nanotubes (PLA/CNTs) and PP/carbon fibers (PP/CF) as composite filaments. Morphologies of printed specimens were analyzed by optical microscopy and scanning electron microscopy. Good correspondence was found between pillar dimensions and edge‐edge pillars distance of computer aided design (CAD) and composites 3D‐printed samples. Their wettability was evaluated by static contact angle (CA) measurements. Results clearly show a significant increase of water CA values up to 50% in all micropatterned samples with respect to flat surfaces. This improvement was achieved by surface microstructuring without the use of nanoparticles and/or chemical treatment. [ABSTRACT FROM AUTHOR]

The unexpected presence of microbubbles in microfluidic systems typically results in performance degradation owing to their ability to obstruct fluidic pathways, causing pressure fluctuations or shear force variations. To develop or enhance undesired bubble-removal strategies, a solid understanding of the fundamental physics governing the bubble-removal processes is essential. In this context, the present study aims to thoroughly investigate the detachment dynamics of different-sized bubbles, ranging in volume from 3 to 75 μL, from a hydrophobic surface fully submerged in a liquid pool while being subjected to direct current electrowetting (DC EW) actuation. From systematic experimental data on the temporal variations in the base radius of retracting bubbles of different volumes subjected to varying DC EW actuations, empirical relationships between detachment process characteristics (e.g., threshold voltage for bubble detachment and detaching time) and physical factors (e.g., bubble volume and applied voltage) can be determined. These relationships are compared with predictions derived from scaling analysis. The findings will provide valuable insight into the elimination of unwanted bubbles in microfluidic systems for biomedical applications and the rapid removal of bubbles to improve heat transfer rates in pool boiling for thermal management applications, including heat exchangers and cooling systems. [ABSTRACT FROM AUTHOR]

This study investigates the impact of surface wettability on the acoustic emissions of cavitation bubbles generated through low-voltage discharge. The behavior of single cavitation bubbles near surfaces with varying wettability is analyzed using high-speed cameras and hydrophones. Cavitation bubble dynamics is observed near three different surfaces: a nearly hydrophilic untreated bare plate, a commercially available Glaco paint-coated plate with hydrophobic properties, and a Sharklet film-coated plate, a commercially available thin film with unique anisotropic wettability. The effects of different wettability conditions on bubble dynamics and the resulting acoustic emissions are compared comprehensively. The dimensionless stand-off distance parameter, defined as the ratio of the stand-off distance from the point of nucleation to the maximum bubble radius in a free field, is found to be crucial in determining the interaction between cavitation bubbles and nearby surfaces, thereby influencing the acoustic signature. Key observations revealed that when the nucleation point is close to the wall, a wall vortex with a unique kink formed due to the hydrophobic coating, while at greater distances, a free vortex is weakened by the hydrophobic nature of the surface. Hydrophobic surfaces, particularly those coated with Sharklet films, amplified sound pressure levels when the nucleation point is close and reduced emissions when farther away. The findings suggest that wettability-modified hydrophobic plates, particularly those with Sharklet film-coatings, may have the potential to manage acoustic emissions from cavitation bubbles effectively. [ABSTRACT FROM AUTHOR]

One of the most significant challenges in microchannel design is the reduction of pressure drops within miniature fluidic pathways. A promising approach involves the manipulation of boundary conditions, mainly through the integration of structured hydrophobic surfaces. The mathematical characterization of these hydrophobic surfaces is achieved through the application of the Navier boundary condition, with the slip length identified as the critical parameter of interest. This paper delves into an in-depth exploration of how varying slip lengths impact the liquid flow dynamics within microchannels with a rectangular cross section. We consider a diverse range of microchannel hydraulic diameters 5–200 μ m and aspect ratios from 1:1 to 1:20 for Reynolds numbers in the laminar range 10–1000. Three-dimensional calculations are performed on both conventional smooth microchannels and those equipped with air-filled groove-structured surfaces. The results are then compared with the analytical solution and experimental results. The application of a hydrophobic structure to a single microchannel surface is resulted in the friction factor reduction by over 30%, while the application of the hydrophobic structure to two opposing walls led to a reduction by over 60%. The maximum throughput is shown to be achieved for a bubble protrusion angle of approximately 0° for a microchannel with a single hydrophobic wall. The greatest reduction in the friction factor was achieved when the bubbles were positioned in a staggered configuration at bubble protrusion angles of approximately –25° for microchannel with two opposing hydrofobic walls. [ABSTRACT FROM AUTHOR]

Self-assembly and molecular spectroscopy are widely used in protein research. However, studies underreported the interaction of rice glutelin (RG) and egg white protein (EWP) under pH-cycle treatments, which had differences between initial and final environment. Herein, the possible interaction mechanism of RG-EWP self-assembly behavior was demonstrated by spectroscopy or other characterization methods under different conditions and proportions. Fourier transform infrared, circular dichroism, intrinsic fluorescence, and UV absorption spectroscopic methods showed changes in the secondary and tertiary structures of RG or RG-EWP. Results also revealed the degree of protein folding and exposure status of aromatic amino acid residues. The nonignorable surface hydrophobic and electrostatic interactions were observed by ζ-potentials and surface hydrophobicity. The electrophoretic analysis showed increased 48 kDa subunits. The high solubility (over 92%) of RG-EWP was discovered as potential functionality at total ratio of 90% and 50% RG. This study improved the asymmetric pH-cycle theoretical mechanism and widened RG-EWP application. [ABSTRACT FROM AUTHOR]

In this study, a novel approach is to apply polyaspartic acid (PASP) as an eco-friendly regulator for the flotation of coking coal, which is different from the conventional use of oil collectors only. Flotation trails showed that adding PASP contributes to a two-way improvement in the yield and ash content of clean coal. SEM-EDS observations directly revealed that adding PASP significantly reduces the coating of high-ash fine slimes on the surface of low-ash coal particles. Contact angle detections and zeta potential analysis presented that the preferential adsorption of PASP hardly affects the adsorption of sodium oleate (NaOL) on the surface of low-ash coal particles but significantly weakens the adsorption of NaOL on the surface of high-ash fine slimes, leading to a remarkably hydrophobic difference. Particle interaction energy calculations verified that adding PASP enlarges the energy barrier between low-ash coal particle and high-ash fine slime. Hence, it can be arrived that the preferential adsorption of PASP affects the adsorption of NaOL on the surface of high-ash fine slime, widens the hydrophobic difference, enlarges the energy barrier between low-ash coal particle and high-ash fine slime, reduces the high-ash fine slime coating, therefore leading to a better flotation performance of lean coal. [ABSTRACT FROM AUTHOR]

An environmentally responsible and sustainable replacement for finite fossil fuels is biodiesel. Because of its amazing qualities, biodiesel is becoming more and more popular as a renewable fuel around the globe. The many approaches, feedstocks, catalysts, comparison standards, reaction kinetics, final product analysis, and final product characterization of biodiesel are covered in this review article. Researchers have used a variety of techniques to produce biodiesel throughout history, with transesterification emerging as the most effective approach in more recent times. Numerous studies on biodiesel feedstock and catalysts to produce high biodiesel yields have been published; nevertheless, it should be highlighted that the type of feedstock must be considered while choosing a catalyst. The review paper highlights the significance of several parameters that are crucial to the manufacture of biodiesel, without which achieving a high yield would be challenging. The literature has also discussed the limitations and advantages of different catalysts, and scientists are currently working to identify the ideal catalyst within certain optimal parameters for the manufacture of biodiesel. Homogeneous reaction‐based biodiesel synthesis has a number of drawbacks, though, such as water content, a laborious purification procedure, and a low tolerance for free fatty acids. To address these issues, scientists have started investigating heterogeneous reactions involving solid catalysts. A large pore network, a moderate‐to‐high density of strong acid sites, a hydrophobic surface, and the ability to control surface hydrophobicity to avoid deactivation are all desirable characteristics of an ideal solid catalyst. Ion exchange resins, sulfated oxides, heterogeneous base catalysts, boron group‐based heterogeneous catalysts, alkaline earth metal oxides, mixed metal oxides, alkali metal oxides, heterogeneous catalysts derived from waste materials, and different approaches to biodiesel synthesis that employ enzymes, carbon‐based heterogeneous catalysts, and ionic liquids as catalysts are among the categories of catalysts that can be used in the production of biodiesel. The finest benchmarks to compare the quality of biodiesel with European and American Society for Testing Material standards. For detailed characterization of the finished product, gas chromatography and nuclear magnetic resonance are the most effective methods. [ABSTRACT FROM AUTHOR]

This study examines hydrophobic surface coatings for stimulation electrodes to mitigate foreign body reactions and encapsulation. Electrospinning of polydimethylsiloxane (PDMS) resin is explored to create fiber structures for electrode coatings. PDMS resin is succesfully processed into fiber mats. Electrospun PDMS fiber structures showed an increased water contact angle (124 °/125 °) in comparison to a cast flat film (102 °). To further increase hydrophobicity, the fabrication process of Slippery Liquid-Infused Porous Surface (SLIPS) systems with a polyurethane substrate and different natural lubricants is assessed with promising results in an increase in water contact angles up to 11°. The findings suggest the potential of these surface coatings to enhance the performance and safety of stimulation electrodes. [ABSTRACT FROM AUTHOR]

The significance of the roughness of particles in flotation has been recognized for several decades. In this study, to investigate the effect of particle roughness, a series of rod milling with different grinding durations is performed on the quartz particles. Subsequently, the particle roundness, wetting rate, and floatability are measured. Finally, the flotation kinetic experiments are conducted based on a fixed particle size, and the interaction energy between rough particles and bubbles is calculated based on extended DLVO (E-DLVO) theory. Results show that by increasing the grinding time, the hydrophobic particle surface roughness increases, and the improved flotation rate constant increases. While the results of the E-DLVO calculation show that the interaction energy barrier between particles and bubbles decreases significantly as the roughness increases, the theoretical calculation and the experimental results confirm that an increase in the particle surface roughness decreases the interaction energy barrier between particle bubbles and increases the flotation rate. [ABSTRACT FROM AUTHOR]

SUMMARY: Lipid droplets (LDs) are unusual organelles that have a phospholipid monolayer surface and a hydrophobic matrix. In oilseeds, this matrix is nearly always composed of triacylglycerols (TGs) for efficient storage of carbon and energy. Various proteins play a role in their assembly, stability and turnover, and even though the major structural oleosin proteins in seed LDs have been known for decades, the factors influencing LD formation and dynamics are still being uncovered mostly in the "model oilseed" Arabidopsis. Here we identified several key LD biogenesis proteins in the seeds of pennycress, a potential biofuel crop, that were correlated previously with seed oil content and characterized here for their participation in LD formation in transient expression assays and stable transgenics. One pennycress protein, the lipid droplet associated protein‐interacting protein (LDIP), was able to functionally complement the Arabidopsis ldip mutant, emphasizing the close conservation of lipid storage among these two Brassicas. Moreover, loss‐of‐function ldip mutants in pennycress exhibited increased seed oil content without compromising plant growth, raising the possibility that LDIP or other LD biogenesis factors may be suitable targets for improving yields in oilseed crops more broadly. [ABSTRACT FROM AUTHOR]

SUMMARY: Land plants have evolved a hydrophobic cuticle on the surface of aerial organs as an adaptation to ensure survival in terrestrial environments. Cuticle is mainly composed of lipids, namely cutin and intracuticular wax, with epicuticular wax deposited on plant surface. The composition and permeability of cuticle have a large influence on its ability to protect plants against drought stress. However, the regulatory mechanisms underlying cuticular wax biosynthesis in response to drought stress have not been fully elucidated. Here, we identified three AP2/ERF transcription factors (DREB26/ERF12, ERF13 and ERF14) involved in the regulation of water permeability of the plant surface. Transmission electron microscopy revealed thicker cuticle on the leaves of DREB26‐overexpressing (DREB26OX) plants, and thinner cuticle on the leaves of transgenic plants expressing SRDX repression domain‐fused DREB26 (DREB26SR). Genes involved in cuticular wax formation were upregulated in DREB26OX and downregulated in DREB26SR. The levels of very‐long chain (VLC) alkanes, which are a major wax component, increased in DREB26OX leaves and decreased in DREB26SR leaves. Under dehydration stress, water loss was reduced in DREB26OX and increased in DREB26SR. The erf12/13/14 triple mutant showed delayed growth, decreased leaf water content, and reduced drought‐inducible VLC alkane accumulation. Taken together, our results indicate that the DREB26/ERF12 and its closed family members, ERF13 and ERF14, play an important role in cuticular wax biosynthesis in response to drought stress. The complex transcriptional cascade involved in the regulation of cuticular wax biosynthesis under drought stress conditions is discussed. Significance Statement: A drought‐inducible Arabidopsis AP2/ERF transcription factor genes, DREB26/ERF12, ERF13, and ERF14, play an important role in cuticular wax biosynthesis in response to drought stress. [ABSTRACT FROM AUTHOR]

Saline soil is composed of abundant soluble salts, exhibiting undesirable properties when used in backfill projects. To address the mentioned problem, a hydrophobic polymer with an active ingredient of hydrosiloxane-containing siloxane was evaluated as a soil additive in this paper. Five groups of specimens were solidified with a fixed dosage of polymer, with initial water contents (IWCs) ranging from 12.8% to 20.8%, to determine the effectiveness of polymer treatment and the effect of IWC. Natural specimens were also prepared to serve as a control condition. Results showed that the polymer formed a hydrophobic interface on the surface of soil particles, causing the shrinkage of the diffuse double layer (DDL) and the flocculation of clay particles. Therefore, the plasticity index reduced, and the fine particles transformed into coarser particles after polymer treatment. Furthermore, the polymer-solidified soil exhibited a significant enhancement in unconfined compressive strength, characterized by an agglomerated microstructure that possessed a high cementing ability. Nevertheless, increasing IWCs continuously induced a decrease in the strength of the solidified soil, especially when the IWC was greater than the optimum water content. The maximum strength increase rate could be up to 98.2%. However, at an IWC of 20.8%, the strength increase rate could still reach approximately 72%. Correlation analysis showed that the solidification mechanism of the hydrophobic polymer was mainly electrostatic interactions. Variable water contents mainly affected the formation of polymer bonding and thickness of DDL. The utilization of hydrophobic polymer for soil improvement in backfill projects shows great potential in light of these findings. [ABSTRACT FROM AUTHOR]

Concrete pavement often experiences accelerated deterioration due to water and chemical ingress through micro-cracks and surface voids. Particularly, the ingress of aggressive agents into the concrete matrix results in irreversible changes and deterioration on its endurance. Numerous studies unveiled that hydrophobic surface protection could be an inexpensive and effective way of enhancing the durability of concrete. This research work aims to assess the feasibility of bio-cement posttreatment for facilitating hydrophobic surface protection, thus enhancing the performance and durability of concrete blocks. Enzyme induced carbonate precipitation (EICP) is one of the promising bio-cement methods. Concrete blocks casted in four different grades were subjected to EICP treatment with different treatment schemes and recipes of cementation media. The treated blocks were tested for water absorption, ultrasonic pulse velocity (UPV) measurements, unconfined compressive strength (UCS), thermal performance, and scanning electron microscopy (SEM). The results indicated that the concrete blocks subjected to EICP posttreatment showed over a 55% reduction in water absorption, a 15% higher UCS and a 6.7% higher UPV when compared with control blocks. The SEM analysis suggested that the EICP posttreatment could enhance the durability of concrete paving blocks by enabling a layer of calcite on the surface and by plugging the transport pore channels of the concrete. Although most of the posttreatment strategies investigated herein were found to be operative, a better response was seen in the posttreatment by spraying scheme with 0.5 mol/L cementation media (CM). With the successful demonstration, the EICP treatment prior to the use of concrete blocks can be recommended to the pavement construction industry. [ABSTRACT FROM AUTHOR]

Inkjet-printed micro-patterns on hydrophobic surfaces have promising applications in the fabrication of microscale devices such as organic thin-film transistors. The low wettability of the surface prevents the inkjet-printed droplets from spreading, connecting to each other, and forming a pattern. Consequently, it is challenging to form micro-patterns on surfaces with low wettability. Here, we propose a sequential printing and drying method to form micro-patterns and control their shape. The first set of droplets is inkjet-printed at a certain spacing and dried. The second set of droplets is printed between these dry anchors on the surface with low wettability. As a result, a stable bridge on the surface with low wettability forms. This printing method is extended to more complicated shapes such as triangles. By implementing an energy minimization technique, a simple model was devised to predict the shape of the inkjet-printed micro-patterns while confirming that their equilibrium shape is mainly governed by surface tension forces. The gradient descent method was utilized with parametric boundaries to emulate droplet pinning and wettability of the anchors and to prevent convergence issues from occurring in the simulations. Finally, the energy minimization based simulations were used to predict the required ink to produce dry lines and triangles with smooth edges. [ABSTRACT FROM AUTHOR]

Two-dimensional carbides and nitrides, known as MXenes, are promising for water-processable coatings due to their excellent electrical, thermal, and optical properties. However, depositing hydrophilic MXene nanosheets onto inert or hydrophobic polymer surfaces requires plasma treatment or chemical modification. This study demonstrates a universal salt-assisted assembly method that produces ultra-thin, uniform MXene coatings with exceptional mechanical stability and washability on various polymers, including high-performance polymers for extreme temperatures. The salt in the Ti3C2Tx colloidal suspension reduces surface charges, enabling electrostatically hydrophobized MXene deposition on polymers. A library of salts was used to optimize assembly kinetics and coating morphology. A 170 nm MXene coating can reduce radiation temperature by ~200 °C on a 300 °C PEEK substrate, while the coating on Kevlar fabric provides comfort in extreme conditions, including outer space and polar regions. Salt-assisted assembly has been developed to achieve large-scale coating of MXene on polymer substrates. The process includes a library of salts and polymer substrates, opening new applications such as thermal management in extreme conditions. [ABSTRACT FROM AUTHOR]

The tripartite ATP-independent periplasmic (TRAP) transporters enable Vibrio cholerae and Haemophilus influenzae to acquire sialic acid, aiding their colonization of human hosts. This process depends on SiaP, a substrate-binding protein (SBP) that captures and delivers sialic acid to the transporter. We identified 11 nanobodies that bind specifically to the SiaP proteins from H. influenzae (HiSiaP) and V. cholerae (VcSiaP). Two nanobodies inhibited sialic acid binding. Detailed structural and biophysical studies of one nanobody-SBP complex revealed an allosteric inhibition mechanism, preventing ligand binding and releasing pre-bound sialic acid. A hydrophobic surface pocket of the SBP is crucial for the allosteric mechanism and for the conformational rearrangement that occurs upon binding of sialic acid to the SBP. Our findings provide new clues regarding the mechanism of TRAP transporters, as well as potential starting points for novel drug design approaches to starve these human pathogens of important host-derived molecules. Biophysical and structural characterization of the TRAP transporter SBP SiaP in complex with a nanobody provides insights into an allosteric mechanism of inhibition. [ABSTRACT FROM AUTHOR]

Cellulose acetate (CA) mixed-matrix membranes incorporating polyvinylpyrrolidone (PVP), bentonite (B or Ben), graphene oxide (GO), and titanium dioxide (TiO2) were prepared by the phase inversion separation technique for oil/water separation. An investigation was performed where the mixed-matrix membrane was tested for the separation performance of hydrophilic and hydrophobic surface properties. An ultrafiltration experiment at the laboratory scale was used to test dead-end ultrafiltration models developed for the treatment performances of oily wastewater under dynamic full-scale operating conditions. Artificial oily wastewater solutions were prepared from hexane, toluene, and engine oil with Tween80 emulsions for oil removal treatment using composite membranes. The impacts of material hydrophilicity, weight loss, permeability, and pore size were investigated, and it was found that the oil retention of membranes with larger pore sizes enabled much more sophisticated water flux. The CA-GO-, CA-B-, and CA-TiO2-incorporated membranes achieved pure water flux (PWF) values of 45.19, 53.41, and 100.25 L/m2h, respectively. The performance of CA-TiO2 in oil/water emulsion rejection was assessed, and the rejection of engine oil/water, toluene/water, and hexane/water mixtures was determined to be 95.21%, 90.33%, and 92.4%, respectively. The CA-based mixed-matrix membrane portrayed better antifouling properties due to enhanced hydrophilicity and water molecules. The CA-TiO2-incorporated membrane possessed the potential to provide high separation efficiency for oily wastewater treatment. This study demonstrates the potential of fine-tuning membrane performances through material hybridization to achieve efficient wastewater treatment. [ABSTRACT FROM AUTHOR]

Composite material based on polyethylene glycol (PEG) and polypyrrole (PPy) polyrotaxanes both encapsulated into α‐cyclodextrins (α‐CDs) macrocycle molecules was synthesized by cross‐linking reaction. The effect of PPy‐αCD polyrotaxane incorporation into the PEG‐αCD polyrotaxane matrix, on the structural, morphological, thermal, and dielectric properties was evaluated and compared to the reference material. Scanning electron microscopy spectroscopy indicates different surface morphologies of this material in comparison to the reference one. In addition, the contact angle measurements and surface free energy attest a hydrophilic surface, while the reference material exhibits a hydrophobic surface. More than that, the presence of the PPy‐αCD cross‐linked into the matrix has a beneficial effect on the thermal properties. The composite material shows an enhanced dielectric constant value of 31,365 at 10 Hz frequency compared to the 38.2 of the reference material, and higher dielectric loss (62,398 vs. 80 at 10 Hz, respectively). The conductivity measurements at 10 Hz frequency indicated for the reference material the value 4.5 × 10−11, while for the material with PPy‐αCD polyrotaxane, the conductivity is three orders of magnitude higher (3.5 × 10−8) confirming the improvements of the electrical properties. [ABSTRACT FROM AUTHOR]

The removal of oil from solid surfaces, such as textiles and plates, remains a challenge due to the strong binding affinity of the oil. Conventional methods for surface cleaning often require surfactants and mechanical abrasion to enhance the cleaning process. However, in excess, these can pose adverse effects on the environment and to the material. This study investigated how bulk nanobubble water can clean oil microdroplets deposited on surfaces like glass coverslips and dishes. Microscopy imaging and further image analysis clearly revealed that these microdroplets detached from both hydrophobic and hydrophilic surfaces when washed with bulk nanobubble water within a fluidic microchannel. Oil contaminant cleaning was also conducted in water as mobile phase to mimic the circumstances that occur in a dishwasher and washing machine. Cleaning on a larger scale also proved very successful in the removal of oil from a porcelain bowl. These results indicate that nanobubble water can easily remove oil contaminants from glass and porcelain surfaces without the assistance of surfactants. This is in stark contrast to negligible results obtained with a control solution without nanobubbles. This study indicates that nanobubble technology is an innovative, low‐cost, eco‐friendly approach for oil removal, demonstrating its potential for broad practical applications. [ABSTRACT FROM AUTHOR]

Digital microfluidic systems, based on the electrowetting-on-dielectric mechanism, allow the manipulation, dispensing, merging, splitting, and mixing of micro- to nanoliter droplets on hydrophobic surfaces by applying voltages to an array of planar electrodes. The manipulation of both a non-aqueous and an aqueous phase droplet in a single experiment has gained considerable interest. This study focuses on characterizing the dispensing and dosing of 1-octanol droplets, merging with a water droplet, and phase separation with minimal residue formation by shearing off the biphasic droplet at a tear-off edge of a hydrophilic well, using optimized actuation parameters. The volume of the 1-octanol droplet dispensed from an L-junction reservoir design increased with increasing dispensing speed. Dispensing can only occur within a certain reservoir volume range. Under identical conditions, 1-octanol droplets could be dispensed with volume variations of less than 0.55%, and manipulated at a maximum velocity of 5.6 mm/s when the frequency of the applied AC voltage was about 200 Hz. At the tear-off edge of the hydrophilic well, the 1-octanol residue on the water droplet was reduced to less than 0.15% of the original 1-octanol droplet volume. The results will be used for future applications, such as for the precise quantitative characterization of the reaction kinetics of complex parallel or sequential interfacial catalytic reactions, for the study of self-assembly processes or for liquid–liquid extractions at the 1-octanol–water interface. [ABSTRACT FROM AUTHOR]

Polytetrafluoroethylene (PTFE) is a fully fluorinated linear polymer with a (CF2-CF2)n backbone. High molecular weight PTFEs are chemically inert while possessing excellent hydrophobic surface properties attributed to their low surface energy. These characteristics make PTFE an excellent candidate for membrane distillation application among all other hydrophobic polymers. In this review, the electrospinning processes of PTFE fibers are discussed in detail with a focus on various electrospinning effects on the resulting fiber morphologies and structures. Due to the high chemical resistance and low solvent solubility, PTFE is typically electrospin with a polymer carrier, such as polyvinyl alcohol (PVA) and/or polyethylene oxide (PEO), using emulsion electrospinning followed by a sintering process. The amount of PTFE in emulsion, types of polymer carriers, electrospinning parameters, and sintering conditions have interconnected effects on the resulting morphological structures of PFTE fibers (e.g., beading or continuous fibers). In addition, electrospun PTFE fibers are further functionalized using methods of co-electrospinning with other hydrophobic polymers as well as incorporations of metallic (ZnO) and inorganic particles (POSS) to improve their performance in membrane distillation. Water contact angles, permeation fluxes, salt rejection rates, and hours of operations are reported for various functionalized electrospun PTFE fibrous membranes to demonstrate their feasibility in membrane distillation applications. In general, this article provides a scientific understanding of electrospun PTFE fibers and their engineering application in membrane distillation. [ABSTRACT FROM AUTHOR]

Dust accumulation on photovoltaic (PV) panels reduces their energy efficiency. Although droplets play a crucial role in the self-cleaning of dust on the surface of PV panels, the underlying mechanism of surface dust self-cleaning in the presence of droplets has not been fully understood. This study aims to investigate the dust removal mechanisms on the surface of blank and coated PV panels and analyze the effects of factors such as dust particle size, PV panel tilt angle, and ash density on droplet self-cleaning efficiency. Our experiments show that superhydrophobic coatings can significantly improve the droplet self-cleaning efficiency and output power of PV panels. The maximum relative power recovery rate of the coated sample is 78.53%, which is much higher than 27.83% of the blank sample. To better understand the droplet self-cleaning mechanism, we analyze the differences in droplet self-cleaning between blank and coated PV panels from a mechanical perspective. Our model explains the main forces and motion modes of dust particles in the presence of droplets, and we find that smaller dust particles are easier to remove than larger particles. Additionally, we find that a smaller inclination angle of the PV panel surface inhibits the dust particle removal process. Finally, we conduct a comparative study between droplet self-cleaning and other self-cleaning methods to evaluate their effectiveness. Our results show that droplet self-cleaning is a more efficient and effective method for removing dust from PV panels. [ABSTRACT FROM AUTHOR]