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Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry 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.)

In this study, inorganic-organic coatings composed of titanium dioxide (TiO 2) as the ceramic component and poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) as the polymer matrix, hybridized with nano-TiO 2 particles, were developed for protecting mild steel (MS) from corrosion. Prior to TiO 2 coating deposition, the MS substrates were pretreated with a bioinspired sub-layer of polydopamine to improve the surface coating adhesion, followed by uniform co-deposition of PVDF-HFP with varying concentrations of embedded nano-TiO 2. The inclusion of nano-TiO 2 further reinforces and densifies PVDF-HFP, providing added corrosion protection. The fabricated coatings were characterized by microscopy, spectroscopy, and diffraction technique, while the corrosion protection properties were evaluated by impedance, potentiodynamic polarization, salt spray, and cyclic corrosion tests. Results showed that both the PVDF-HFP matrix and TiO 2 contents had substantial effects on the coatings' thermal stability, hydrophobicity, and surface mechanical properties. The coatings also exhibited satisfactory corrosion resistance, with increased impedance modulus to roughly sixteen orders of magnitude for the TiO 2 -PVDF-HFP coating containing 0.5 g/L TiO 2 , relative to the untreated MS substrate. This result can be attributed to the low surface energy of PVDF-HFP, coupled with the dense structure and added physical barrier of nano-TiO 2. Overall, these hybrid polymer/ceramic coatings are poised to help design other highly resilient and hydrophobic surface coatings with durable protection against corrosion. [ABSTRACT FROM AUTHOR]

A durable and efficient hydrophobic/superoleophilic MIL-88A(Fe)@sponge (MS) with high throughput was fabricated via the dip-coating technique. Its adsorption capacities for pump oil, peanut oil, and CCl4 were 32.13 g g−1, 34.85 g g−1, and 34.25 g g−1, respectively. The hydrophobic surface of MS has excellent chemical resistance and physical stability in harsh environments. [ABSTRACT FROM AUTHOR]

Highlights In the present work, the impact of corona aging on the dielectric, thermal, and surface properties of silicone rubber filled with different nanofillers such as alumina (Al2O3), aluminum trihydrate (ATH), boron nitride (BN), and titania (TiO2) are studied. The surface degradation of the silicone rubber nanocomposites after corona aging is evaluated through contact angle measurement, atomic force microscopy (AFM) studies, and by water droplet‐initiated corona inception voltage studies. Alumina filled silicone rubber shows less reduction in surface and hydrophobic properties after corona aging. Water droplet initiated corona inception voltage (CIV) under negative DC voltage is much higher than under positive DC and AC voltages. Al2O3/TiO2‐ filled silicone rubber samples show better CIV performance. The Dielectric Response Spectroscopy (DRS) indicates that TiO2 filled silicone rubber insulating material possesses higher permittivity at lower frequencies. Boron nitride added composites have high thermal conductivity whereas ATH filled silicone rubber composites shows higher decay rate, as observed through laser‐induced thermography studies. A significantly high surface leakage current is observed in all samples after corona aging. The Space Charge Limited Current (SCLC) studies clearly indicate that inclusion of nano‐fillers resulted in an increase in crossover voltage and trap density values compared to base silicone rubber. Al2O3 filled silicone rubber exhibits lower surface roughness even after corona aging. High thermal conductive composites show better performance even after corona aging. ATH, and BN filled silicone rubber have improved thermal conductivity by 35.2% and 76.3%. TiO2 filler added silicone rubber exhibits high permittivity with low tan δ. Al2O3 filled silicone rubber has minimal surface and volume leakage current Crossover voltage and the trap density get enhanced on addition of fillers to the base polymer. [ABSTRACT FROM AUTHOR]

\nHIGHLIGHTSPolymer nanocomposites are increasingly used in insulation applications for enhanced electrical properties. However, there are intricate parameters that control the properties of the polymer, and hence investigations are required. This paper attempts to correlate the electrical properties of Epoxy/Organically modified montmorillonite clay composites with the free volume resulting from the incorporation of the Organically modified montmorillonite clay filler of 2, 5, and 7 weight per cent (wt.%). Positron annihilation spectroscopy has been used to compute the fractional free volume and free volume. The free volume percentage is observed to increase with the incorporation of 2 and 5 wt.% and reduces at 7 wt.%. A similar trend is observed in the average size of free volume. The filler increases the AC electric breakdown strength by 20%, arc resistance by 5%, and comparative tracking index by 10% at 5 wt.%. Thermal conductivity is seen to increase marginally with the filler. The surfaces of the composites are hydrophilic at 2 and 7 wt.%, and at 5 wt.%, it is hydrophobic. Longer durations of water diffusion render the surfaces of the nanocomposites hydrophobic. Fourier transform infrared spectroscopy investigations reveal broadening of peak, increase in peak intensity and stretching of Si–O–Si bonds at 5 wt.% of filler due to exfoliation. An attempt has been made to understand the results of electrical parameters based on the results of positron annihilation lifetime spectroscopy and thermal conductivity. Water diffusion is minimal at 5 wt.% of OMMT.Highest CTI of 588 is achieved at 5 wt.%.Arc resistance of 400 s is achieved at 5 wt.%. OMMT.Proof tracking is higher at 5 wt.% of OMMT.Surface is hydrophobic at 5 wt.% OMMT.Water diffusion is minimal at 5 wt.% of OMMT.Highest CTI of 588 is achieved at 5 wt.%.Arc resistance of 400 s is achieved at 5 wt.%. OMMT.Proof tracking is higher at 5 wt.% of OMMT.Surface is hydrophobic at 5 wt.% OMMT. [ABSTRACT FROM AUTHOR]

Laboratory sciences and disease diagnostics need accelerated medical tests, ease of testing for patients, and lower diagnostic costs. In this respect, one of the most innovative methods is paper-based microfluidic analysis tools, called micro-PAD. Since the chemical-based micro-PADs need sufficient blood to show an accurate blood test, the shape of the micro-PADs, the blood quantity, and the droplet flow to reach the end of the microchannels are important. Therefore, this research showed the liquid droplet motion on a heterogeneous (hydrophobic and hydrophilic) surface using the lattice Boltzmann method, and two star-shaped micro-PADs were modeled to investigate the effect of the droplet size and the droplet deflection from the center of the micro-PAD on liquid flow in microchannels. Based on the obtained results, fluid behavior was similar in two patterns (ten-pointed pattern and four-pointed pattern). This study compared the effects of parallel, convergent, and divergent channels in a four-pointed pattern on fluid velocity. The off-center error of the droplet was considered at the initial moment. The obtained results confirmed the direct relationship between the increased deviation of the center and the lack of uniformity in the fluid penetration. The present simulation results were validated against the laboratory data. [ABSTRACT FROM AUTHOR]

To solve the frost failure problem on super-hydrophobic surfaces in low temperature and high humidity environment, the slippery surface was fabricated by coating with lubricant oil on the rough super-hydrophobic surface. The wettability and microstructures of slippery surfaces were determined. The experimental platforms of frost prevention system and vertical defrosting test system were designed and constructed to investigate the dynamic behavior of frosting and defrosting on slippery surface, super- hydrophobic surface and pure copper surface. The results show that on the slippery surface, the dynamic lubricant film can be generated in the porous and rough structures of the substrate, which can effectively reduce the frost crystal nucleation and prevent the formation of "ice bridge". The frost mass and propagation speed wave on slippery surface are significantly lower than those on super-hydrophobic surface and pure copper surface, which shows better frost inhibition performance. During the process of vertical defrosting and drainage, the defrosting efficiency on cach surface is proportional to the frosting mass. The mass and surface coverage of residual water upon defrosting on slippery surfaces are slightly higher than that on super-hydrophobic surface and lower than that on pure copper surface, which exhibits good defrosting and drainage performance. [ABSTRACT FROM AUTHOR]

Chitosan (CHT) and propolis (P) are natural materials with antiseptic, anti-inflammatory, antimicrobial, and mucoadhesive properties with many applications in orthopaedia dentistry. The objective of this study was to develop a low molecular weight (LMW) and medium molecular weight (MMW) chitosan polymeric system with propolis at different concentrations (0.31%, 0.62%, 1.25%, 2.5%, and 5%) and to evaluate the effect in terms of their cell interaction with dental pulp fibroblasts. FTIR spectra of both molecular weights CHT's films with propolis show increased transmittance bands at 1730–1720 cm−1 and 1460 cm−1, indicating the presence of propolis ethanolic extract in the organic matrix. Contact angles test to determine hydrophobicity CHT films functionalized with propolis exhibit a more hydrophobic surface as propolis concentration increases. Cytotoxicity showed synergy between chitosan and propolis; the highest proliferation was observed in LMW CHT with 0.31% of propolis. Membranes made with CHT of both molecular weights plus propolis in an inflammatory stage (cells previously treated with LPS) can inhibit the expression of NF-k-B, MAPK, and VEGF. A polymeric system based on chitosan/ethanolic extract propolis could be a future alternative treatment for oral ulcers. [ABSTRACT FROM AUTHOR]

Hydrophobic surfaces exhibit unique surface effects and hold broad potential across numerous domains, including anti-icing, condensation, and self-cleaning. Conventionally, droplets on hydrophobic surfaces have been conceptualized as spherical segments to predict contact angles. However, a droplet deposited on hydrophobic surfaces tends to be flattened at the bottom due to gravity, leading to a discrepancy between the experimental observation and prediction derived from the Cassie–Baxter equation. Here, we propose an approximation that divides the distorted droplet into upper and lower segments, i.e., simplifying its morphology into a double-radius contour. This approach leads to a more accurate prediction of the contact angle on hydrophobic structured surfaces. The deviation between experiment and our model is less than 1.7%. Further water evaporation was conducted to investigate the transition condition from the Cassie–Baxter state to the Wenzel state, and we show that the critical transition radius for substrates with varied microstructural geometry parameters consistently falls slightly below the theoretical prediction, which is attributed to an inaccurate assessment of the structure angle. Finally, we demonstrate that the stability of the Cassie–Baxter state can be enhanced by employing hierarchical micro-/nanostructures on the surface. This research advances our foundational comprehension of wetting phenomenon and the stability of the Cassie–Baxter state. [ABSTRACT FROM AUTHOR]

Droplet impact on surfaces integrated with the electrowetting effect has been recently explored to control droplet spreading and recoiling behavior on hydrophobic surfaces. With the integration of electrowetting, the spreading of the impacting droplet on hydrophobic surfaces increases, whereas the rebound tendency is suppressed. The present work numerically investigates the droplet impact on hydrophobic surfaces under partial electrowetting (EW) effects. In partial EW, the electrowetting effect is immediately cut off once the droplet attains the maximum spreading diameter. In addition, based on the energy conservation principle, a mathematical model is developed to predict the maximum spreading diameter of the droplet and its kinetic energy during bouncing for different parameters. The partial EW technique enhances the maximum spreading diameter and reduces the recoiling time compared to full EW and no EW effect. The recoiling time decreases with the increase in voltage amplitude, frequency, Weber number, and surface wettability. [ABSTRACT FROM AUTHOR]

The impact of droplets on solid surfaces is a crucial fluid phenomenon in the additive industry, biotechnology, and chemistry, where controlling impact dynamics and duration is essential. While extensive research has focused on flat substrates, our understanding of impact dynamics on curved surfaces remains limited. This study seeks to establish phase diagrams for the process of droplet impact on solid spheres and further quantitatively describe the effect of curvature through theoretical analysis. It aims to determine the critical conditions between different impact outcomes and also establish a scaling relationship for the contact time. Here, the post-impact outcome regimes occurring for a wide range of Weber numbers (We) from 1.2 to 173.8, diameter ratio (λ) of solid spheres to nanodroplets from 0.25 to 2, and surface wettability (θ) from 21° to 160°, through the molecular dynamics simulation method (MD) and theoretical analysis. The MD simulations reveal that the phase diagrams of droplet impacts on hydrophilic, hydrophobic, and superhydrophobic spheres differ, with specific distinctions focusing on rebound and three different forms of dripping. Furthermore, a theoretical model based on the principle of energy conservation during impact on superhydrophobic surfaces has been developed to predict the critical conditions between rebound and dripping states, showing good agreement with simulation results. Additionally, a new scaling relationship of contact time for droplet impact on superhydrophobic spherical surfaces has also been established by extending and modifying the existing models, which also agrees well with the simulated results. These insights provide a foundational understanding for designing surface structures. [ABSTRACT FROM AUTHOR]

Lipophilicity is an essential parameter of a compound that determines the solubility and pharmacokinetic properties that determine the transport of the drug to the molecular target. Dimers of dipyridothiazines are diazaphenothiazine derivatives exhibiting diverse anticancer potential in vitro, which is related to their affinity for histone deacetylase. In this study, the lipophilicity of 16 isomeric dipyridothiazine dimers was investigated theoretically and experimentally by reversed-phase thin-layer chromatography (RP-TLC) in an acetone–TRIS buffer (pH = 7.4). The relative lipophilicity parameter RM0 and specific hydrophobic surface area b were significantly intercorrelated, showing congeneric classes of dimers. The parameter RM0 was transformed into parameter logPTLC by use of the calibration curve. Molecular descriptors, ADMET parameters and probable molecular targets were determined in silico for analysis of the pharmacokinetic profile of the tested compounds showing anticancer activity. The analyzed compounds were tested in the context of Lipinski's rule of five, Ghose's rule and Veber's rule, confirming their bioavailability. [ABSTRACT FROM AUTHOR]

A superhydrophobic surface is defined as having a contact angle exceeding 150 °C, indicating a remarkable ability to repel water. Generally, superhydrophobicity originates from the utilization of low‐surface‐energy materials with unique micro‐ and nanostructures. Superhydrophobic surfaces have gained considerable recognition and are widely employed in diverse areas for anti‐icing, oil‐water separation, anticorrosion, self‐cleaning, blood‐repellent, and antibacterial applications. These surfaces can greatly enhance industrial processes by yielding significant performance improvements. In this review, we introduce the basic theories that provide a foundation for understanding the hydrophobic properties of superhydrophobic surfaces. We then discuss current techniques for fabricating superhydrophobic coatings, critically analyzing their strengths and limitations. Furthermore, we provide an overview of recent progress in the application of superhydrophobic materials. Finally, we summarize the challenges in developing superhydrophobic materials and future trends in this field. The insights provided by this review can help researchers understand the basic knowledge of superhydrophobic surfaces and obtain the latest progress and challenges in the application of superhydrophobic surfaces. It provides help for further research and practical application of superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

Styrene-Isobutylene-Styrene (SIBS) is a high-performance biocompatible elastomeric material. However, its low surface energy and hydrophobic nature limit its widespread application in the field of implantable materials within the human body. In this study, UV-initiated polymerization was employed to prepare SIBS-acrylic acid surface-grafted co-polymer. Subsequently, collagen protein (Coll) surface modification of SIBS was achieved through a coupling reaction with acrylic acid, resulting in the production of Collagen Surface-Modified SIBS, denoted as SIBS-AA-Coll. Characterization was carried out using techniques such as infrared spectroscopy, thermal analysis, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and water contact angle measurements. The results demonstrated that, with a UV exposure time of 4 min and a nBP:nAA ratio of 15:100, the grafting ratio reached 9.4%, significantly improving the hydrophilicity of the SIBS surface. In vitro cytotoxicity tests and in vivo animal implantation experiments indicated that Collagen Surface-Modified SIBS exhibited excellent biocompatibility. [ABSTRACT FROM AUTHOR]

This study employed atmospheric plasma (AP) pretreatment to enhance the hydrophobicity of polytetrafluoroethylene (PTFE) thin films. When a PTFE thin film was deposited on the substrate pretreated with AP, the deposition followed the Frank-van der Merwe mode at hydrophilic regions and the Volmer–Weber mode at hydrophobic regions, thereby causing the PTFE thin film to have continuous bumps. In accordance with the Wenzel and Cassie equation, increasing the surface roughness of hydrophobic materials increased their hydrophobicity. The water contact angle increased from 100° to 110° after deposited PTFE thin film on substrate pretreated with AP. Finally, the water contact angle further increased to 115° after annealed in nitrogen gas. A salt spray test demonstrated that the hydrophobic PTFE thin film had excellent corrosion resistance and stability. This hydrophobic film preparation technology can be used for the protective film of electronic device, sensor, solar cell and so on. [ABSTRACT FROM AUTHOR]

The effect of extreme water repellency, called the lotus effect, is caused by the formation of a Cassie–Baxter state in which only a small portion of the wetting liquid droplet is in contact with the surface. The rest of the bottom of the droplet is in contact with air pockets. Instrumental methods are often used to determine the textural features that cause this effect—scanning electron and atomic force microscopies, profilometry, etc. However, this result provides only an accurate texture model, not the actual information about the part of the surface that is wetted by the liquid. Here, we show a practical method for estimating the surface fraction of texture that has contact with liquid in a Cassie–Baxter wetting state. The method is performed using a set of ethanol–water mixtures to determine the contact angle of the textured and chemically equivalent flat surfaces of AlSI 304 steel, 7500 aluminum, and siloxane elastomer. We showed that the system of Cassie–Baxter equations can be solved graphically by the wetting diagrams introduced in this paper, returning a value for the texture surface fraction in contact with a liquid. We anticipate that the demonstrated method will be useful for a direct evaluation of the ability of textures to repel liquids, particularly superhydrophobic and superoleophobic materials, slippery liquid-infused porous surfaces, etc. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA) is a popular material used in the packaging industry. However, it is vulnerable to moisture, which can affect its performance and durability. Introducing hydrophobic substances, such as tetraethyl orthosilicate (TEOS) and hexadecyltrimethoxysilane (HDTMS), on the top layer of PVA can help maintain the excellent properties of PVA under high-humidity conditions. The low compatibility of hydrophobic materials with the hydrophilic layers allows them to aggregate more easily. To overcome these issues, we focused on the effects of particle size when increasing the coating suspension's dispersibility. A carbon quantum dot (CQD) suspension is an appropriate novel solvent for hydrophobic TEOS/HDTMS coating suspensions because its particles are small and light and exhibit good dispersibility. The CQD suspension formed a smooth hydrophobic coating on the TEOS/HDTMS materials. Furthermore, the uniformly coated PVA with the CQD suspension exhibited a water contact angle of 110°. The water droplets remained intact without being absorbed, confirming the effectiveness of the surface coating facilitated by CQDs. These results suggested that CQDs improved the dispersibility and enhanced the coating quality of TEOS/HDTMS on PVA. Enhancing the hydrophobicity of PVA is ideal for applications in packaging and other fields. [ABSTRACT FROM AUTHOR]

This work includes the preparation of Fe3O4 NPs coated with mesoporous silica nanoparticles (MSNs). The combination between two different materials could improve the removal efficiency of pollutants from wastewater. The surface modification of magnetic nanoparticles could reduce the agglomeration. The Fe3O4-MSNs surface was modified with aspartic acid liked with the adsorbent surface via hydrophobic linker (1,4-phenylene diisothiocyanate, PDITC) to effectively remove the methylene blue (MB) dye from the contaminated water. The particles size was ranged between 110 and 160 nm, as estimated by SEM and TEM. The surface zeta potential of the surface was found to be negatively at pH above 2.5. The nanosorbent efficiency was evaluated at different conditions such as pH, contact time and initial MB concentration. The maximum adsorbed amount of the MB was estimated to be 135 mg/g at 200 mg/L MB concentration and 80 min contact time. The adsorption isotherm fits with the Langmuir model and pseudo-second-order kinetics. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to fabricate the acrylic-based polymeric composite coating with a hydrophobic surface associated with natural oil polyol (NOP) and polydimethylsiloxane with the incorporation of 3 Wt.% SiO2 nanoparticle (SiO2np) against the corrosive NaCl media. Design/methodology/approach: The structural properties of the formulated polymeric composite coatings were investigated by using Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, water contact angle (WCA) and cross-hatch (X-Hatch) tests. The WCA measurement was used to study the surface wettability of the formulated polymeric composite coatings. The corrosion protection performance of the nanocomposite coated on the mild steel substrate was studied by immersing the samples in 3.5 Wt.% NaCl solution for 30 days using electrochemical impedance spectroscopy. Findings: The enhanced polymeric composite coating system performed with an excellent increase in the WCA up to 111.1° which is good hydrophobic nature and very high coating resistance in the range of 1010 Ω attributed to the superiority of SiO2np. Originality/value: The incorporation of SiO2np into the polymeric coating could enhance the surface roughness and hydrophobic properties that could increase corrosion protection. This approach is a novel attempt of using NOP along with the addition of SiO2np. [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]

Polyvinyl alcohol (PVA) coating has attracted intense attention due to its biodegradability and high gas barrier properties. However, the high gas barrier properties deteriorate at elevated humidity. Herein, we aimed to prepare PVA based coating with high water resistance by incorporating nano-SiO2 (S) and citric acid (CA), and polyethylene (PE) film was selected as a substrate model. The results showed that the PVA/S/CA coated PE films had better water vapor and oxygen barrier performance than the uncoated PE films. With an optimized mass ratio (PVA/S/CA10%), the coated PE films' water vapor permeability decreased by 46.53% at 90% RH, and the oxygen permeability decreased by four orders of magnitude at 0% relative humidity (RH). Besides, increased surface roughness and a more hydrophobic surface were observed in the coated PE films. Overall, these coated PE films still retained high transparency and were mechanically robust, making them potential candidates for the flexible food packaging field. [ABSTRACT FROM AUTHOR]

Due to the amphiphilic nature of phospholipids in the cell membrane, the amphipathicity of the nanomedicine plays a crucial role in the endocytosis. However, limited biological characterization methods restrict the study of the state of nanoparticles with different amphiphilicities on cell membranes. The understanding of interaction of amphiphilic particle with cell membrane is still lacking. Herein, by combining the dissipative particle dynamics (DPD) with the framework construction of mesoporous silica nanoparticles (MSNs), we demonstrate the enhanced endocytosis induced by the hydrophobicity. DPD results confirm that the presence of hydrophobic groups on the surface of nanoparticles can disturb the integrity of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membrane and induce activation of phospholipids to a higher energy level, thereby facilitating the wrapping of nanoparticles. To validate the simulation findings, uniform MSNs with hydrophilic pure silica framework and two types of amphiphilic MSNs with varying hydrophilic organic groups in the framework are rationally synthesized by using different silane precursors. The obtained three kinds of MSNs show similar diameter (~ 100 nm) and mesopores (~ 2 nm), but distinct hydrophobicity/hydrophilicity ratio. The phenyl-bridged MSN with a carbon content of 27.1% exhibits enhanced cellular uptake, consistent with the theoretical simulation results. This work sheds light on how the surface amphipathicity influences endocytosis through the interaction with cell membrane. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology 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.)

This study examines the wettability behaviour of 304 stainless steel (304SS) and Ti-6Al-4V (Ti64) surfaces after sequential nanosecond (ns) and picosecond (ps) laser texturing; in particular, how the multi-scale surface structures created influence the lifecycle of surface hydrophobicity. The effect of different post-process treatments is also examined. Surfaces were analysed using Scanning Electron Microscopy (SEM), a white light interferometer optical profiler, and Energy Dispersive X-ray (EDX) spectroscopy. Wettability was assessed through sessile drop contact angle (CA) measurements, conducted at regular intervals over periods of up to 12 months, while EDX scans monitored elemental chemical changes. The results show that sequential (ns + ps) laser processing produced multi-scale surface texture with laser-induced periodic surface structures (LIPSS). Compared to the ns laser case, the (ns + ps) laser processed surfaces transitioned more rapidly to a hydrophobic state and maintained this property for much longer, especially when the single post-process treatment was ultrasonic cleaning. Some interesting features in CA development over these extended timescales are revealed. For 304SS, hydrophobicity was reached in 1–2 days, with the CA then remaining in the range of 120 to 140° for up to 180 days; whereas the ns laser-processed surfaces took longer to reach hydrophobicity and only maintained the condition for up to 30 days. Similar results were found for the case of Ti64. The findings show that such multi-scale structured metal surfaces can offer relatively stable hydrophobic properties, the lifetime of which can be extended significantly through the appropriate selection of laser process parameters and post-process treatment. The addition of LIPSS appears to help extend the longevity of the hydrophobic property. In seeking to identify other factors influencing wettability, from our EDX results, we observed a significant and steady rate of increase in the carbon content at the surface over the study period. [ABSTRACT FROM AUTHOR]

Kapok fibers (KFs) exhibit a distinctive hollow tubular structure and hydrophobic surface, positioning them as intriguing materials with a leading role in developing new materials for various applications. In this study, KFs from Ceiba speciosa trees underwent modification with soy lecithin (SL) and graphite (G) particles. The wax on KFs primarily comprised hydrophobic compounds, including bis(2-ethylhexyl) phthalate, N–N-dimethyldodecanamide and 1-chloro-dodecane. These compounds interacted favorably with the alkyl chains of SL, exposing the SL charge groups to the medium, as confirmed by X-ray photoelectron spectroscopy (XPS) and wettability increase. Incorporating SL and G particles to the KFs improved their thermal stability and charring capability. KFs modified with SL and G (at 13 wt% or 16 wt%) were added to aqueous solutions of hydroxypropyl methylcellulose (HPMC) at 30 g L−1, forming homogeneous dispersions that were molded and oven-dried to create xerogel composites. Regardless of the G content, all xerogels exhibited compressive elastic modulus of 23 ± 1 kPa, maximum strain of 60% strain at 5.6 ± kPa stress, and after unloading, the xerogels recovered 77% of their original height. Their porosity amounted to 68 ± 3%. The xerogels showed a maximum sound absorption coefficient (SAC) of approximately 0.6 at 2 kHz, making them interesting sustainable materials for building and architecture. Surface resistivity and volume resistivity values amounted to 3.8 × 108 Ω/square and 8.84 × 108 Ω cm, respectively, indicating that the xerogel composites displayed antistatic properties and potential application as packing material. [ABSTRACT FROM AUTHOR]

This study investigates the influence of microstructure patterns on the hydrophobic properties of surfaces of 3D-printed objects generated using photopolymer resin. Various arrangements and designs of microstructures on the surface of 3D-printed objects were examined. Leveraging the superior resolution of stereolithography printers (SLA) over fused deposition modeling, intricate microfeature designs were well-implemented. The experiments involved a range of structures on the surface of the 3D-printed objects, including precisely defined arrays of microcylinders, microchannels, and other complex designs generated by parametric equations. The hydrophobicity of the 3D-printed objects was assessed through the water droplet test, revealing a spectrum of results ranging from hydrophobic to weakly hydrophobic, and to hydrophilic surfaces. Light microscopy was employed to characterize the surface morphological properties of the 3D-printed objects, which were then correlated with the measured contact angles. It was discovered that the 3D-printed objects with microstructures formed using parametric functions exhibited patterns with irregularities and fluctuations along all directions or axes, resulting in a higher degree of hydrophobicity compared to structured matrices with pillared arrays. However, some surfaces created with parametric functions resulted in an anisotropic system where the material properties varied along one direction, while the other direction exhibited a flat, planar surface. These anisotropic systems were found to be less hydrophobic according to the water droplet test. [ABSTRACT FROM AUTHOR]

In this work, a series of fluorinated microemulsions were synthesized using thermally decomposable N-dodecyl-N,N-dimethylamine N-oxide (LDAO) as surfactant. Then, polybutylene terephthalate nonwoven fabrics (PBT) were coated with microemulsion and heat-treated. Superhydrophobic and oil-repellent modified PBT with WCA (water contact angle) of about 152°, a sliding angle of about 2.1°, and oil repellency grade of 8 were prepared. The effect of surfactants on the surface wettability of hydrophobic materials was analyzed by TG-DTA, XPS, and WCA tests. The results show that surfactants decrease the WCA of hydrophobic materials, but LDAO can eliminate this effect by heat treatment. The anti-corrosion and permeability of LDAO coatings were compared with those of conventional fluorinated coatings through degradation and anti-permeability tests. It was shown that the LDAO fluorinated superhydrophobic coating is more resistant to corrosion by chemical solutions and significantly improves the impermeability of porous materials. Anti-fouling and self-cleaning tests showed excellent anti-fouling and self-cleaning properties on several common substrate surfaces modified with LDAO fluorinated microemulsions. It is expected that these new LDAO fluorinated microemulsions have promising applications in the preparation of corrosion-resistant surfaces and impermeable structures. [ABSTRACT FROM AUTHOR]

The probiotic potential of Shouchella clausii is widely recognized, but little is known about its adhesive properties. Hence, this study aims to investigate the adhesion potential and cell surface properties of four human-origin S. clausii strains (B619/R, B603/Nb, B106, and B637/Nm). We evaluated epithelial adhesion, Extracellular Matrix (ECM) binding, aggregation ability, and cell surface hydrophobicity and used genome analysis for validation. Our results demonstrate that adhesion capability is a strain-specific attribute, with significant variations observed among the four strains. B619/R, B603/Nb, and B106 displayed stronger adhesion properties than B637/Nm. Supplementary adhesion assays showed that B637/Nm displayed high hydrophobicity, significant auto-aggregation, and significant mucin-binding abilities. Conversely, B619/R, B603/Nb, and B106 had mildly hydrophobic surfaces and low aggregation abilities. Genome annotation revealed the presence of various adhesion proteins in four strains. Notably, the reduced adhesion potential of B637/Nm was supported by the absence of the cell wall surface anchor family protein (LPxTG motif), which is crucial for interactions with intestinal epithelial cells or mucus components. Further, docking studies provided insights into the interaction of adhesion proteins with gut mucins. These findings contribute to a better understanding of how S. clausii strains interact with the gut environment, facilitating the development of probiotic formulations tailored for improved gut health and well-being. [ABSTRACT FROM AUTHOR]

Microhelices are important structures capable of overcoming low Reynolds number limitations and can be used in various applications. The fabrication of such microhelices is a challenge as existing fabrication techniques are restrictive in material choices and require sophisticated equipment. In this work, we demonstrate a simple top‐down approach to fabricate microhelical structures using surface modification of helical electrospun fibers to produce both hydrophilic, silica‐coated (Si‐HMPF), and hydrophobic, caramel sol‐based (Ca‐HMPF) magnetic microhelices post‐modification. The glassy coating obtained on the surface in both cases facilitated obtaining magnetic microhelices via mechanical fracture of the fibers by grinding at room temperature. SEM images of the samples confirm the successful fabrication of microhelical structures which resemble the popular microswimmer morphology. The FTIR and VSM characterization were performed to study the functional groups present and the magnetic nature of the fabricated microhelices. The thermal stability of the samples was investigated using DSC and TGA studies. Both hydrophilic and hydrophobic magnetic microhelices were successfully fabricated through a simple sol‐based coating technique and confirmed by a wettability study. Highlights: Helical microstructures are an important classification of micro/nanomaterial synthesis.A simple method for the fabrication of magnetic polymeric microhelices is proposed and discussed in detail.The current challenges in fabricating such structures are discussed.The advantages of using a simple surface modification technique is summarized. [ABSTRACT FROM AUTHOR]

The development of ultra-low near-infrared reflectivity coatings with outstanding engineering properties remains a challenge in laser stealth materials research. Herein, we reported a laser stealth coating with outstanding mechanical properties, super-hydrophobicity, and an ultra-low near-infrared reflectivity for 1.06 μm wavelength. The effects of the mass ratio of graphene to nano-SiO2, the proportion of total filler, the addition of KH560, the mass ratio of Polydimethylsiloxane (PDMS) to acrylic-modified polyurethane (APU), and the addition of dioctyl phthalate (DOP) on the coating properties were thoroughly discussed. The coating can achieve a low reflectivity of 9.3% at 1.06 μm and a high water contact angle of 152° at a mass ratio of 7:3 for PDMS to APU and 6:4 for graphene to nano-SiO2 with a total filler amount of 40 wt%. KH560 can play a bridging role between the blended resin matrix and nano-SiO2, which can significantly improve the impact strength of the coating. The DOP, which contains a polar ester group and a non-polar carbon chain structure, can be inserted between the molecular chains of the resin to weaken the intermolecular force of the resin, so that the flexibility of the coating can be significantly improved. Adding KH560 at 4 wt% and DOP at 1 wt%, resulted in a coating with ultra-low near-infrared reflectivity of 1.06 μm (9.3%), super-hydrophobic properties, outstanding adhesion strength (grade 2), flexibility (2 mm), and impact strength (50 kg cm). The above super-hydrophobic ultra-low near-infrared reflectivity coating has significant potential for use in the field of laser stealth equipment, and it can serve as a useful reference for optimizing the mechanical properties of super-hydrophobic functional coatings. [ABSTRACT FROM AUTHOR]

The ability to switch adhesion strength is a highly desirable property for adhesives applied in a wet environment. The major challenges involve the presence of a water layer between the substrate and adhesive, and the incorporation of efficient switching mechanisms. Despite the recent progresses in devising such systems, there exist several intrinsic limitations in the current strategies, such as high residual adhesion, the use of solid–liquid transition, or thin film configurations. Herein, a channeled poly(N‐isopropylacrylamide) (PNIPAm) hydrogel containing bio‐inspired dopamine‐comonomers is reported, which undergoes temperature‐controlled reversible switching of underwater adhesion on both hydrophilic and hydrophobic surfaces. The introduction of microscopic channels inside the hydrogel, achieved by removing a sacrificial agarose network, greatly facilitates water removal from the interface and thus promotes underwater adhesive strength. On glass, the maximum adhesive stress of the channeled hydrogel can reach six times that of hydrogels without channels. Additionally, high switching efficiency and low residual adhesion can be achieved by the thermal phase transition of the PNIPAm network, also demonstrated by the capture and release of lightweight, irregular, fragile, and biological objects using the hydrogel. The channeling strategy provides implications for designing future underwater adhesive systems for, e.g., soft robotics or biomedical applications. [ABSTRACT FROM AUTHOR]

Due to its scientific significance and practical applications, the common natural phenomena of drops impacting on inclined surfaces have attracted extensive attention. Previous research has primarily reported the distinct morphology and dynamic behavior of drops impacting on inclined superhydrophobic surfaces compared to the impact on the horizontal scenarios. One distinguished feature of drop impingement on inclined surfaces is the asymmetric shapes of the drop, which accounts for different underlying physics compared to the impacts on horizontal surfaces. However, the impact forces exerted by the inclined surface during impingement have remained unknown. In this study, we present a direct measurement of the normal impact force of drops on inclined superhydrophobic surfaces using a high-precision force sensor. We observe the temporal evolution of the force and identify two peak forces occurring during the spreading and retraction stages, respectively. Our findings lie on investigating the variation of these two peak forces with the normal Weber number, based on scaling arguments. We reveal that the asymmetrical morphology of the drop must be taken into account especially in the scenarios of large impact velocities and large tilt angles to revise the theoretical model of the second peak force. The physics reported in this work sheds new light on the impingement of drops. [ABSTRACT FROM AUTHOR]

Plasma spray-physical vapor deposition (PS-PVD) is a promising third-generation thermal barrier coatings (TBCs) technique. Feather-like columnar TBCs with excellent strain tolerance and low thermal conductivity can be achieved using PS-PVD. However, molten CMAS (CaO–MgO–Al2O3–SiO2) can penetrate coatings and accelerate PS-PVD TBCs failure due to the feather-like columnar structure. Hence, a strategy is proposed to alleviate molten CMAS corrosion. The super-hydrophobicity structure is fabricated via laser texturing on the surface of PS-PVD TBCs to repel molten CMAS wetting and spreading. Then, a thin layer of the Al-film is deposited on the laser-textured surface. Next, the Al-modified layer is in situ synthesized after vacuum heat treatment, preventing the infiltration of molten CMAS into the TBCs and reducing the coating damage. The results show that the contact angle of laser textured and Al-modified PS-PVD TBCs (LT-Al) at room temperature increased from 12.3° to 168.8°. The wetting and spreading behavior of molten CMAS of as-sprayed (AS), laser textured (LT), and LT-Al coatings is observed in situ at 1230 °C for 1800 s. The LT-Al coatings exhibited excellent CMAS corrosion resistance, attributed to the laser-textured micro-nano structures and Al-modified layer protection. The findings may be an effective approach for solving the disadvantage of PS-PVD feather-like columnar structure TBCs. [ABSTRACT FROM AUTHOR]

Iron-based Fischer–Tropsch synthesis (FTS) catalyst is widely used for syngas conversion, but its iron carbide active phase is easily oxidized into Fe3O4 by the water produced during reaction, leading to the deterioration of catalytic performance. Here, we show an efficient strategy for protecting the iron carbide active phase of FTS catalyst by surface hydrophobization. The hydrophobic surface can reduce the water concentration in the core vicinity of catalyst during syngas conversion, and thus inhibit the oxidation of iron species by water, which enhances the C − C coupling ability of catalyst and promotes the formation of long-chain olefins. More significantly, it is unraveled that appropriate shell thickness plays a crucial role in stabilizing the iron carbide active phase without Fe3O4 formation and achieving good catalytic performance. The iron carbide active phase is easily oxidized by the water produced during Fischer-Tropsch synthesis, which leads to a deterioration in catalytic performance. Here, the authors present a strategy to protect iron carbide by applying surface hydrophobization. [ABSTRACT FROM AUTHOR]

In low-rank and oxidized coal flotation, the pore structure on particle surfaces can significantly affect the bubble-particle collisional adhesion process, which in turn affects the flotation performance. In this study, to understand its mechanism, the collisional interaction process between bubbles and substrates with a single pore was observed throjugh a self-made system, and the interaction force was measured during the adhesion and detachment process. The results proved that the pore accelerated the kinetic energy dissipation of the bubbles after collision and largely shortened the induction time during the adhhesion process. The induction time on the perforated substrate was an order of magnitude shorter than that on the smooth surface. The interaction force measurement results showed that bubble interaction behavior on smooth and perforated surfaces was essentially the same, which suggests that the single pore on hydrophobic surface can accelerate bubble adhesion without affecting adhesion stability, thus strengthening bubble – particle adhesion. [ABSTRACT FROM AUTHOR]

A new two-step method for developing a nanocomposite of polypropylene (PP) decorated with photocatalytically active TiO2 nanoparticles (nTiO2) is proposed. This method involves the low-temperature plasma functionalization of polypropylene followed by the ultrasound-assisted anchoring of nTiO2. The nanoparticles, polymeric substrate, and resultant nanocomposite were thoroughly characterized using nanoparticle tracking analysis (NTA), microscopic observations (SEM, TEM, and EDX), spectroscopic investigations (XPS and FTIR), thermogravimetric analysis (TG/DTA), and water contact angle (WCA) measurements. The photocatalytic activity of the nanocomposites was evaluated through the degradation of methyl orange. The individual TiO2 nanoparticles ranged from 2 to 6 nm in size. The oxygen plasma treatment of PP generated surface functional groups (mainly -OH and -C=O), transforming the surface from hydrophobic to hydrophilic, which facilitated the efficient deposition of nTiO2. Optimized plasma treatment and sonochemical deposition parameters resulted in an active photocatalytic nTiO2/PP system, degrading 80% of the methyl orange under UVA irradiation in 200 min. The proposed approach is considered versatile for the functionalization of polymeric materials with photoactive nanoparticles and, in a broader perspective, can be utilized for the fabrication of self-cleaning surfaces. [ABSTRACT FROM AUTHOR]

Herein, an anticorrosive and hydrophobic surface for Ti–6Al–4V was prepared through one-step anodic etching. The results showed that wettability was adjusted by current density and etching time. In particular, the maximum water contact angle (WCA) reached ~ 160.9° at a current density of 0.25 A cm−2 for 420 s. Energy dispersive spectroscopy and X-ray photoelectron spectroscopy showed the existence of spontaneous surface passivation, which was also verified by Tafel curves. In addition, Ecorr and icorr exhibited good anticorrosion properties on the surface of the Ti–6Al–4V after anodic etching. Furthermore, the change in surface adhesion was consistent with the change in the WCA after anodic etching. In conclusion, the one-step anodic etching can provide a convenient way to realize anticorrosion and superhydrophobic Ti–6Al–4V surface. Highlights: A superhydrophobic surface can be formed on Ti–6Al–4V substrate through one-step anodic etching. The maximum WCA of the surface reached ~ 160.9°. The change tendency of the adhesive force is contrary to that of the WCA. The large area and low-cost anticorrosive property of Ti–6Al–4V can be adjusted by current density. [ABSTRACT FROM AUTHOR]

Botulinum neurotoxins (BoNTs) are the most potent toxins known and are used to treat an increasing number of medical disorders. All BoNTs are naturally co-expressed with a protective partner protein (NTNH) with which they form a 300 kDa complex, to resist acidic and proteolytic attack from the digestive tract. We have previously identified a new botulinum neurotoxin serotype, BoNT/X, that has unique and therapeutically attractive properties. We present the cryo-EM structure of the BoNT/X-NTNH/X complex and the crystal structure of the isolated NTNH protein. Unexpectedly, the BoNT/X complex is stable and protease-resistant at both neutral and acidic pH and disassembles only in alkaline conditions. Using the stabilizing effect of NTNH, we isolated BoNT/X and showed that it has very low potency both in vitro and in vivo. Given the high catalytic activity and translocation efficacy of BoNT/X, low activity of the full toxin is likely due to the receptor-binding domain, which presents very weak ganglioside binding and exposed hydrophobic surfaces. Botulinum neurotoxins (BoNTs) are a family of protein toxins produced by clostridial bacteria that cause muscle paralysis, and exhibit structural and functional diversity within the BoNTs family. Here, the authors report the cryo-EM structure complex of a newly identified serotype BoNT/X with their partner protein NTNH/X and reveal the complex's pH-dependent stability and receptor-binding properties. [ABSTRACT FROM AUTHOR]

We investigate the phenomena of crater formation and gas release caused by projectile impact on underwater beds, which occurs in many natural, geophysical and industrial applications. The bed in our experiment is constructed of hydrophobic particles, which trap a substantial amount of air in the pores of the bed. In contrast to dry beds, the air–water interface in a submerged bed generates a granular skin that provides rigidity to the medium by producing skin over the bulk. The projectile's energy is used to reorganize the grains, which causes the skin to crack, allowing the trapped air to escape. The morphology of the craters as a function of impact energy in submerged beds exhibits different scaling laws than what is known for dry beds. This phenomenon is attributed to the contact line motion on the hydrophobic fractal-like surface of submerged grains. The volume of the gas released is a function of multiple factors, chiefly the velocity of the projectile, depth of the bed and depth of the water column. [ABSTRACT FROM AUTHOR]

Single‐walled carbon nanotubes (SWCNTs) are desirable nanoparticles for sensing biological analytes due to their photostability and intrinsic near‐infrared fluorescence. Previous strategies for generating SWCNT nanosensors have leveraged nonspecific adsorption of sensing modalities to the hydrophobic SWCNT surface that often require engineering new molecular recognition elements. An attractive alternate strategy is to leverage pre‐existing molecular recognition of proteins for analyte specificity, yet attaching proteins to SWCNT for nanosensor generation remains challenging. Toward this end, a generalizable platform is introduced to generate protein‐SWCNT‐based optical sensors and use this strategy to synthesize a hydrogen peroxide (H2O2) nanosensor by covalently attaching horseradish peroxidase (HRP) to the SWCNT surface. A concentration‐dependent response is demonstrated to H2O2, confirming the nanosensor can image H2O2 in real‐time, and assess the nanosensor's selectivity for H2O2 against a panel of biologically relevant analytes. Taken together, these results demonstrate successful covalent attachment of enzymes to SWCNTs while preserving both intrinsic SWCNT fluorescence and enzyme function. It is anticipated this platform can be adapted to covalently attach other proteins of interest including other enzymes for sensing or antibodies for targeted imaging and cargo delivery. [ABSTRACT FROM AUTHOR]

In this study, the heat transfer performance of a two-phase closed thermosyphon with super-hydrophobic (SH-phobic) condenser and super-hydrophilic (SH-philic) evaporator is investigated, and the results are compared with those of a bare condenser. At 100–200 W, the total thermal resistance on the SH-phobic surface decreases by up to 10.40 %, 0.41 % and 27.44 % compared with the bare condenser surface at filling ratios of 0.25, 0.5, and 0.75, respectively. However, the total thermal resistance increases by 55.06 %, 411.35 % and 128.33 % from 300 to 400 W, respectively. The critical heat flux for the SH-phobic surface is lower than for the bare surface. The SH-phobic surface performs better than bare surface in the low-power region (100–200 W), but not in the high-power region above 300 W. Therefore, the input power should be considered when applying the SH-phobic surface to the condensing section. [ABSTRACT FROM AUTHOR]

The formation of amyloid fibrils is a common feature of many protein systems. It has implications in both health, as amyloid fibrils are implicated in over 30 degenerative diseases, and in the biological functions of proteins. Surfaces have long been known to affect the formation of fibrils but the specific effect depends on the details of both the surface and protein. Fully understanding the role of surfaces in fibrillization requires microscopic information on protein conformation on surfaces. In this paper replica exchange molecular dynamics simulation is used to investigate the model fibril forming protein, A β (10–40) (a 31-residue segment of the amyloid-beta protein) on surfaces of different hydrophobicity. Similar to other proteins A β (10–40) is found to adsorb strongly onto hydrophobic surfaces. It also adopts significantly different sets of conformations on hydrophobic and polar surfaces, as well as in bulk solution. On hydrophobic surfaces, it adopts partially helical structures, with the helices overlapping with beta-strand regions in the mature fibril. These may be helical intermediates on the fibril formation pathway, suggesting a mechanism for the enhanced fibril formation seen on hydrophobic surfaces. [ABSTRACT FROM AUTHOR]

Thermal recovery techniques for producing oil sands have substantial environmental impacts. Surfactants can efficiently improve thermal bitumen recovery and reduce the required amount of steam. Such a technique requires solid knowledge about the interaction mechanism between surfactants, bitumen, water, and rock at the nanoscale level. In particular, oil sands ores have extremely complex mineralogy as they contain many clay minerals (montmorillonite, illite, kaolinite). In this study, molecular dynamics simulation is carried out to elucidate the unclear mechanisms of clay minerals contributing to the bitumen recovery under a steameanionic surfactant co-injection process. We found that the clay content significantly influenced an oil detachment process from hydrophobic quartz surfaces. Results reveal that the presence of montmorillonite, illite, and the siloxane surface of kaolinite in nanopores can enhance the oil detachment process from the hydrophobic surfaces because surfactant molecules have a stronger tendency to interact with bitumen and quartz. Conversely, the gibbsite surfaces of kaolinite curb the oil detachment process. Through interaction energy analysis, the siloxane surfaces of kaolinite result in the most straightforward oil detachment process. In addition, we found that the clay type presented in nanopores affected the wettability of the quartz surfaces. The quartz surfaces associated with the gibbsite surfaces of kaolinite show the strongest hydrophilicity. By comparing previous experimental findings with the results of molecular dynamics (MD) simulations, we observed consistent wetting characteristics. This alignment serves to validate the reliability of the simulation outcomes. The outcome of this paper makes up for the lack of knowledge of a surfactant-assisted bitumen recovery process and provides insights for further in-situ bitumen production engineering designs. [ABSTRACT FROM AUTHOR]

[Display omitted] The catalytic performance of immobilized lipase is greatly influenced by functional support, which attracts growing interest for designing supports to achieve their promotive catalytic activity. Many lipases bind strongly to hydrophobic surfaces where they undergo interfacial activation. Herein, the behavioral differences of lipases with distinct lid structures on interfaces of varying hydrophobicity levels were firstly investigated by molecular simulations. It was found that a reasonable hydrophilic/hydrophobic surface could facilitate the lipase to undergo interfacial activation. Building on these findings, a novel "nest"-like superhydrophobic ZIFs (ZIFN) composed of hydrophobic ligands was prepared for the first time and used to immobilize lipase from Aspergillus oryzae (AOL@ZIFN). The AOL@ZIFN exhibited 2.0-folds higher activity than free lipase in the hydrolysis of p-Nitrophenyl palmitate (p-NPP). Especially, the modification of superhydrophobic ZIFN with an appropriate amount of hydrophilic tannic acid can significantly improve the activity of the immobilized lipase (AOL@ZIFN-TA). The AOL@ZIFN-TA exhibited 30-folds higher activity than free lipase, and still maintained 82% of its initial activity after 5 consecutive cycles, indicating good reusability. These results demonstrated that nanomaterials with rational arrangement of the hydrophilic/hydrophobic surface could facilitate the lipase to undergo interfacial activation and improve its activity, displaying the potential of the extensive application. [ABSTRACT FROM AUTHOR]

[Display omitted] It has been a challenge to prepared polyether block amide (PEBA) fibrous membrane via solution electrospinning. The only few reported methods though involved hazardous solvents and surfactants which were against the principle of green chemistry. In this work, uniform fibrous membrane of PEBA was successfully fabricated by solution electrospinning with a bio-based solvent dihydrolevoglucosenone (Cyrene). To further improve the mechanical strength and adsorption performance of the PEBA membrane, a hierarchical magnesium hydrogen phosphate (MgHPO 4 ·1.2H 2 O, MHP) was synthesized to blend evenly into the PEBA matrix. A Janus MHP/PEBA membrane with one side of hydrophobic surface and the other side of hydrophilic surface was subsequently prepared, which exhibited fast adsorption, high capacity, good selectivity and reusability towards ibuprofen, acetaminophen, carbamazepine and triclosan. In addition, the Janus membrane showed high removal efficiency of the above contaminants in secondary wastewater effluent with good long term stability. It demonstrated that this Janus MHP/PEBA membrane had a good potential in practical wastewater treatment. [ABSTRACT FROM AUTHOR]

Surface-modified bacterial cellulose, namely, BC-g-PMMA fiber, was synthesized by graft polymerization. The BC-g-PMMA fiber was employed as a surface modifying agent for a porous polylactic acid (PLA) scaffold, which was prepared through phase inversion. In this study, BC-g-PMMA 1:1 (BC: MMA mole ratio of 1:1), BC-g-PMMA 1:3 (BC: MMA mole ratio of 1:3), and BC-g-PMMA 1:6 (BC: MMA mole ratio of 1:6) were prepared using methyl methacrylate (MMA) as a grafting monomer under sonication-assisted reactions. Various characterization methods, including FTIR, DSC, and TGA, were employed to confirm that BC-g-PMMA exhibited an amphiphilic structure. Next, the PLA/BC-g-PMMA composite scaffold was successfully prepared using a solvent-induced phase inversion technique involving a solvent exchange step (dioxane diffused out while water diffused in); due to this process, the honeycomb structure of the PLA/BC-g-PMMA composite contained amphiphilic surfaces, and the wettability and cell adhesion behavior of the porous material were manipulated. In the absence of BC-g-PMMA, porous PLA exhibited a hydrophobic surface and no wicking properties. In contrast, the PLA/BC-g-PMMA composites showed an ability to wick, which was related to the grafted PMMA moiety; the higher the grafted PMMA ratio was, the slower the wicking ability due to the decrease in the surface energy of the composites. Due to their tailored surface chemistry, these materials played a role in the adherence of the composites to proteins and human gingival fibroblasts. Therefore, amphiphilic spongy PLA/BC-g-PMMA composites are promising materials for tissue engineering and spheroid (3D cell structure) scaffolds. [ABSTRACT FROM AUTHOR]

BACKGROUND: Membrane distillation (MD) for desalination encounters significant hurdles as a result of pore wetting, leading to reduced permeate flux or deterioration in permeate quality over time. Therefore, membranes used in MD must be highly hydrophobic to prevent liquid from entering the pores and contaminating the permeate stream. In this study, a thin layer of MoS2‐TiO2 composite was coated using poly (DOPA) as an adhesive to enhance attachment. Two coating methods, interlinking and layering, were compared to determine the most effective method for forming a thin hydrophobic coating layer onto PVDF‐PES hollow fiber membrane. RESULTS: Interestingly, this study revealed that increasing the number of dipping cycles led to higher flux, defying conventional expectations. This unexpected outcome is likely to have resulted from the thicker coatings creating a more hydrophobic surface, reducing water molecule adhesion and preventing wetting. Consequently, the membrane demonstrated enhanced flux despite its increased thickness. Among the membranes tested, the MoS2‐TiO2/PVDF‐PES membrane coated using the layering method exhibited the best performance, leading to a flux of 2.06 kg m−2 h−1 and 99.99% salt rejection. This superior performance can also be attributed to the membrane's hydrophobic properties, evident in its water contact angle (WCA) of 99°. By contrast, the interlinking method resulted in lower performance, with a permeate flux of 1.70 kg m−2 h−1 and 99.96% salt rejection, which is likely to have resulted from its lower WCA of 86°. CONCLUSION: The findings from this study suggest that the coating method has the potential to greatly improve membrane distillation performance through wettability modification rather than altering membrane porosity. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Ice accumulation poses considerable challenges in transportation, notably in the domain of general aviation. The present study combines the strengths and limitations of conventional aircraft deicing techniques with the emerging trend toward all-electric aircraft. This study aims to utilize laser-induced graphene (LIG) technology to create a multifunctional surface, seamlessly integrating hydrophobic properties with efficient electrical heating to mitigate surface icing effectively. We investigated the utilization of a 10.6 μm CO2 laser for direct writing on polyimide (PI), a widely used insulating encapsulation material. From the thermomechanical perspective, our initial analysis using COMSOL Multiphysics software (V5.6) revealed that when the laser power P exceeds 5 W, the PI substrate experiences ablative damage. The experimental results show that when P ≤ 5 W, an increase in power has a positive impact on the quality, surface porosity, roughness reduction, line-spacing reduction, and water contact-angle enhancement of the graphene. Conversely, when P > 5 W, higher power negatively affects both the substrate and the graphene structure by inducing excessive ablation. However, it influences the graphene line height positively and is consistent with overall experimental–simulation congruence. Furthermore, the incorporation of high-quality graphene resulted in a surface that exhibited higher contact angles (CA > 120°), lower energy consumption, and higher heating efficiency compared to the use of traditional electrically heated materials for anti-icing applications. The potential applications of this one-step fabrication method extend across various industries, particularly aviation, marine engineering, and other ice-prone domains. Moreover, the method has extensive prospects for addressing pivotal challenges associated with ice formation and serves as an innovative and efficient anti-icing technology. [ABSTRACT FROM AUTHOR]

This research investigates the generation and evaluation of various geometric surface textures on PLA components produced via fused filament fabrication (FFF). Textures, including grooves, pyramids, and cylinders, were created at different depth levels on the PLA surfaces. The surface quality of these textures was assessed using a 3D optical system, focusing on area parameters such as Sa and Sz. The wettability of each texture was evaluated through contact angle and sliding angle tests, revealing the ability to modulate contact angles and achieve either hydrophobic or hydrophilic surfaces depending on the texture type. Subsequently, pairs of textured PLA pieces were bonded using a cyanoacrylate adhesive following standardised protocols, and shear tests were conducted to determine the maximum shear stress at bond (τmax) of each texture. Notably, textured surfaces generally exhibited hydrophobic properties that reduce the adhesion between the adhesive and the piece, leading to reduced maximum shear stress at bond values compared to non-textured surfaces. However, groove textures notably increased τmax values. The results were analysed to establish correlations between surface quality, wettability, and shear strength. This comprehensive evaluation aims to elucidate the influence of surface texture on the mechanical performance and adhesive properties of FFF-manufactured PLA components. [ABSTRACT FROM AUTHOR]

For a wide range of applications, paper materials require effective protection against the destructive effect of water, which is most effectively realized by superhydrophobic coatings. In recent years, a considerable amount of scientific research has been carried out in this area, focusing particularly on biogenic resources. With this contribution, we go one step further and examine how biogenic materials can be transferred into aqueous dispersions and coated onto paper via existing technologies. With this paper coating, based on a hydrophobic cellulose derivative in combination with a structurally similar wax, thermally regenerable flower-like surface morphologies are obtained via self-assembly, where the hydrophobic cellulose polymer acts as a structural template for the co-crystallization of the wax component. Such hydrophobic structures in the low micrometer range ensure perfectly water-repellent paper surfaces with contact angles > 150° starting from coating weights of 5 g/m2. The dispersion can be successfully applied to a variety of commercially available paper substrates, whereby the effects of different roughness, porosity, and hydrophobicity were investigated. In this context, a certain roughness of the base paper (Sa ~ 1.5–3 µm) was found to be beneficial for achieving the highest possible contact angles. Furthermore, the approach proved to be paper process-compatible, recyclable, and regenerable, whereby the processing temperatures allow the coating properties to be thermally generated in situ. With this work, we demonstrate how biogenic waxes are very well suited for superhydrophobic, regenerative coatings and, importantly, how they can be applied from aqueous coatings, enabling simple transfer into the paper industry. [ABSTRACT FROM AUTHOR]