Search

A particularly significant metric in the initial phase and in industrial applications is the contact angle (CA), which arises from the surfaces’ wetting behavior. One of the commonly employed processes for separation in the mineral processing industry is froth flotation. The principal goal of this work is to describe the behavior of flotation (collision, attachment, and detachment to the air bubble) as it corresponds to the requirement and use of CA in surface wetting behavior, especially in the context of minerals. This review and previous part provide information on the CA measurement method, the wetting characteristics of mineral surfaces, the variables affecting CA measurements, and the associated implications for the flotation process. The preceding part (Part I) included a broad examination, the idea of a static and dynamic CA, and a statement of the sessile drop method. The current part (II) for the initial-time examines multiple methods and approaches that employed both historical and existing flotation research to investigate the literature on the foundation of CA of various minerals as function of the approach used for CA assessment, which provides an in-depth analysis of questions relating to the determination of CA on real surfaces or powder materials including the evaluation of the impact of the surface heterogeneity, particle fraction size and shape, roughness, and the drop/bubble size with coordination the foremost later information on how these factors affect surface wettability. At that point, the data could be combined into a flotation demonstration or used to evaluate the viability of increasing flotation productivity and provide further insight into this procedure. There are a lot of publications on the subject of CA across several sciences, but the quantity is likewise low when looking at the CA of minerals or flotation, and much more so if it comes to review articles. Using the data and information gathered from the CA measurement and its connection to flotation recovery, the primary objective is to ascertain if any of these variables considerably impact the hydrophobicity of the mineral surface. At that point, the information could either be incorporated into a flotation demonstration or utilized to evaluate the feasibility of increasing flotation productivity and provide further insight into the process. [ABSTRACT FROM AUTHOR]

An anion-responsive boron-containing π-conjugated polymer was synthesized via the Sonogashira coupling polymerization. The 11B NMR, UV/vis absorption, and fluorescence spectra confirmed the formation of an anion complex between the polymer and tetrabutylammonium fluoride (TBAF). Thin films were then prepared either by the pre-addition method, where the thin film was prepared using a solution of the polymer and TBAF, or by the post-addition method, where the polymer thin film was treated with an aqueous TBAF solution. The contact angle measurements revealed an enhancement in wettability with both methods. Consequently, wettability can be controlled via anion-complex formation at the surface. [ABSTRACT FROM AUTHOR]

Moisture damage (MD) in bituminous mixtures occurs due to the loss of cohesion in the bitumen or adhesion between the binder and aggregates. The existence of moisture may influence the bonding between aggregates and bitumen, which may affect the moisture susceptibility of the bituminous mix. Therefore, there is a need to understand the bonding-debonding properties and the moisture susceptibility of binders and mixes, at the material selection stage. Surface free energy (SFE) method is one of the proven techniques to quantify the moisture susceptibility of bituminous mixtures, by using contact angle (CA) determination of the component materials of the mix. This study aimed to evaluate the effect of hydrated lime (HL) on the moisture susceptibility of bituminous mixtures, with control (VG30) bitumen and pyro-oil modified bitumen (POMB) having different percentages of pyro oil, using the SFE approach. Also, the study compared the SFE characteristics of VG30 and POMB with and without the optimum content of HL. POMB binders were prepared by the addition of high-density polyethylene (HDPE) pyro oil in percentages of 1, 3, and 5% in a control bitumen. HL was added as 20%, 25%, and 30% by weight of bitumen in VG30 and POMB bitumen. The aggregates used in the study were limestone, basalt, gravel, and their SFE components were directly considered from the literature. The sessile drop method was used to measure the CA of bitumen and, in turn, determine the various SFE parameters using Van Oss–Chaudhury–Good theory. The moisture susceptibility of mixtures with and without HL was evaluated and compared. From the results, the MD resistance of the bituminous mixtures with modified and unmodified bitumen was found to be increased after the optimum of HL, depending upon the type of aggregates used. Basalt has a 27.41%, 23.38%, and 10.48% greater energy ratio (ER) with POMB1/25, POMB3/25, and POMB5/30, respectively, than VG30/30, the highest ER in modified base bitumen. This indicates that HDPE pyro-oil treatment improves MD resistance for basalt. Whereas for limestone and gravel, VG30/30 gives a maximum value of ER as compared to any other combination of HL modified POMB. The ER values would assist highway agencies in selecting the most compatible binder–aggregate combinations. [ABSTRACT FROM AUTHOR]

AbstractOur research described in this paper investigated the environmental degradation of polypropylene (PP) films incorporating pro-oxidants and assessed their impact on the ecosystem. Weathering aging effects were monitored through Fourier-Transform Infrared (FTIR) analysis, revealing significant changes in carbonyl, hydroxyl and amorphous regions post-aging. The presence of pro-oxidants intensified these changes, indicating higher oxidation levels. Contact angle measurements demonstrated decreased hydrophobicity upon aging, particularly pronounced in pro-oxidant-containing films (initial contact angle: 87.79° for PP/1% Co/1% Fe, sample (F6) decreased to 79.24° after aging). Differential Scanning Calorimetric (DSC) analysis revealed decreased melting temperatures (initial Tm: 159.5 °C for F6 decreased to 148 °C after aging) and the crystallinity post-aging (initial χ: 73.25% for F6 decreased to 60.17% after aging), suggesting increased susceptibility to degradation. Thermogravimetric Analysis (TGA) showed decreased thermal stability after aging, especially in PP/pro-oxidant films; the Tonset (T5); 432.00 °C for F6, decreased to 268.00 °C after aging; where Tonset is the temperature corresponding to 5% weight loss. Biodegradation tests indicated enhanced biodegradability in the pro-oxidant-containing films, with cobalt and ferrous stearate mixtures showing the highest degradation degrees (e.g., PP/1% Co/1% Fe: ≈ 77% biodegradation after 140 days). Ecotoxicological evaluations, including microbial toxicity and plant germination and growth tests, revealed no inhibitory effects of the degradation products on soil flora or plant growth, confirming their nontoxic nature. Overall, we believe this comprehensive study provides insights into the environmental fate of PP films with pro-oxidants, highlighting their potential for accelerated degradation without adverse ecological impacts. [ABSTRACT FROM AUTHOR]

The chemical enhanced oil recovery (cEOR) uses substances to improve the mobility of petroleum in reservoirs. Among these substances are the surfactants, whose purpose is to change the wettability and interfacial tension (IFT). We focus on experiments of surfactants in rocks from Chicontepec Paleochannel. CTAB, DTAB and SDS surfactants in brines of NaCl and KCl and mineral oil were investigated for reduction of IFT and contact angle alteration. The sessile and pendant drop methods were used to determine the IFT. The electrical affinity of the rock surface, dissolved ions, and the surfactant molecules, play key roles in the alteration of wettability and IFT. Thus, one scheme of interactions between the electrical charges is proposed on the basis of the rocky characterization and the following results: the lowest contact angle was 106° with CTAB at 0.01 wt% in brines at 9.25 g/L NaCl, and 108° with SDS at 0.01 wt% in brines at 20 g/L NaCl. The smallest IFT was 0.813 dyn/cm with CTAB at 0.5 wt% in brines at 5 g/L KCl. This work serves as first assessments of these surfactants to enhance the production in Chicontepec, employing cheap tensoactives to increase the applicability. Besides, these results will guide future displacement tests as cEOR lab simulation. [ABSTRACT FROM AUTHOR]

AbstractTheobromine, a bioactive compound found in cacao beans, is recognized for its pharmacological health benefits, such as improving heart health by lowering blood pressure, enhancing cognitive function, supporting respiratory health, providing antioxidant benefits, reducing inflammation, and promoting dental health. However, its limited solubility in water poses challenges for therapeutic applications, necessitating methods to enhance its solubility. The approach to enhance its bioavailability making it more effective for medicinal use and easier to incorporate into various pharmaceutical and nutraceutical products. Hydrotropic solubilization, utilizing the amphiphilic nature of sodium benzoate, is employed to improve the solubility of theobromine. Through systematic investigation of varying concentrations (0–3 mol/L) of sodium benzoate and temperature conditions ranging between 303 and 333 K, this study is aimed to elucidate their effects on the solubility of theobromine. Standardized protocols were utilized to measure the concentration of dissolved theobromine in sodium benzoate solutions, while thermodynamic properties were analyzed to understand the underlying mechanism. The study discovered that the solubility of theobromine was enhanced by sevenfold in the presence of sodium benzoate. Thermodynamic analysis revealed the solubilization process to be entropy-driven. Additionally, contact angle estimations confirmed increased hydrophobicity with higher sodium benzoate concentration, facilitating the solubilization of theobromine in the aqueous phase. Furthermore, FTIR analysis indicates that the solubilization of the bioactive compound occurs exclusively subsequent to traversing the minimum hydrotropic concentration (MHC). [ABSTRACT FROM AUTHOR]

The efficient dewatering of montmorillonite (Mt)-containing coal slime is still an urgent problem to be solved in coal preparation plant. In this study, the dewatering effect of poly(o-phenylenediamine)/Poly dimethyl diallyl ammonium chloride (POPD/PDADMAC) combined filter aid on Mt-containing coal slime was studied. The dewatering performance of combined filter aid was investigated by vacuum filtration test. The action mechanism of combined filter aid was revealed by contact angle, zeta potential, cake pore and atomic force microscope (AFM). The co-adsorption principle of the combined filter aid was elucidated based on density functional theory (DFT) and molecular dynamics simulation (MD). Compared to PDADMAC, the combined filter aid has better performance for dewatering of Mt-containing coal slime, and has the advantage of low reagent dosage. The combined filter aid can greatly reduce the Mt potential, increase the Mt contact angle, and increase the porosity of the filter cake. There was a co-adsorption effect between the combined filter aid. Specifically, there were ion–dipole interaction, cation–π interaction and Cl ions bridged electrostatic interaction between POPD and PDADMAC. This study has developed a novel combined filter aid, which provides theoretical and technical support for the high-efficiency pressure filtration dewatering of Mt-containing coal slime in coal preparation plants. [ABSTRACT FROM AUTHOR]

Hydrocarbon oil collectors used in coking coal flotation are nonrenewable resources, and their collecting performance is difficult to meet current industry needs. In this study, cottonseed oil biodiesel (CSOB) was prepared from cottonseed oil by alkali-catalyzed transesterification, and experimental studies on flotation of 1/3 coking coal were carried out. The results showed that the clean coal yield was about 75% when the use of CSOB was 2000 g t−1. The results of contact angle, FTIR and XPS tests showed that the oxygen-containing groups of CSOB were adsorbed on the hydrophilic spots on the surface of coal particles, and the surface hydrophobicity of coal particles was increased. The ash level of the clean coal with the addition of CSOB during flotation was essentially the same as with the addition of an equivalent amount of diesel oil. [ABSTRACT FROM AUTHOR]

For dropwise condensation of water over a textured surface, the condensation rate is limited by the conduction resistance of the droplet. Conduction models with varying levels of approximation have been reported in the literature. In the present study, the conduction resistance of a spherical-cap droplet is derived by regression analysis of data generated by 3D numerical simulation. Results show that conduction resistance is sensitive to the choice of contact angle and droplet radius. The proposed model has significant differences from reported models which are based on 1-D and 2-D approximations. An important source of discrepancy is traced to additional heat flux localized at the three-phase contact line. Equivalently, high local heat flux serves to lower thermal resistance between the vapor-liquid interface and the condensing wall. The prediction of the droplet growth rate using the proposed conduction model is in good agreement with the experiments reported in the literature. The improved conduction resistance correlation is incorporated in the model for a space- and time-resolved dropwise condensation cycle for vapor condensing from moist air. Simulations with the improved condensation model show close agreement with experimental data, justifying the utility of an improved correlation for conduction resistance. [ABSTRACT FROM AUTHOR]

The present work critically analyses the thermal characteristics of diverse molar (0.03, 0.06, and 0.09 M) Ag decorated GO hybrid nanofluids at constant 0.05 wt.%. The study broadly encompassed the synthesis, characterization, stability, thermophysical properties, reactivity, and contact angle measurements on copper substrates using varied molar Ag-GO hybrid nanofluids. The thermal impact of these hybrid nanofluids was evaluated across a temperature range of 293–333 K, encompassing thermal conductivity, specific heat, viscosity, surface tension, and density. The results illustrate that increasing the molarity of Ag over GO significantly influenced the thermal properties of the hybrid nanofluids. Notably, the most substantial improvements in thermal conductivity are observed at 333 K, reaching 30.12, 22.63, and 17.13% for 0.09, 0.06, and 0.03 M Ag-GO, respectively, compared to the base fluid. Furthermore, central composite design approach (CCD) was employed to establish correlations between the experimental and predicted thermal conductivity enhancement ratio (K-ratio) results. In conclusion, these studies underscore a promising insight that the optimizing of Ag molarity in GO hybrid nanofluids holds substantial potential for enhancing heat transfer performance across diverse heat transfer applications. [ABSTRACT FROM AUTHOR]

3D printed mixed matrix membrane (MMM) thin film, as a novel adsorbent, was introduced for the extraction of two steroid hormones from wastewater and tap water samples before their determination by high-performance liquid chromatography. The designed adsorbent was fabricated as thin film utilizing digital light processing (DLP) 3D printing. The thin film was made of acrylate photo resin, graphitic carbon nitride (g-C3N4), and polyvinylpyrrolidone and its application was investigated for thin film microextraction of 17β-estradiol (E2) and estrone (E1). The morphology of the 3D printed film surface and its chemical changes were studied using field emission scanning electron microscopy and attenuated total reflectance-Fourier transform infrared spectroscopy, respectively. The surface wettability of the proposed MMM films was measured by water contact angle analysis and its porosity was studied by N2 adsorption/desorption analysis. To attain optimal microextraction performance, optimization of both thin film composition and microextraction procedure was conducted, followed by a thorough evaluation of figures of merit under the optimized conditions. The limits of detection and quantitation were determined to be 1.5 and 5 µg L−1 for both E2 and E1. The linear dynamic range for both compounds was from 5 to 150 µg L−1. The method's repeatability was investigated on a single film for 6 extractions, as well as on 3 different films and the relative standard deviation values were 4.43 and 4.91 for E2 and 5.36 and 6.03 for E1, respectively. [ABSTRACT FROM AUTHOR]

To improve the durability of the photobioreactor antibiofouling surface for microalgal cultivation, a series of photoreactive poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) were successfully synthesized and used to modify ethylene-vinyl acetate (EVA) films by a surface coating and UV light grafting method. Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy analysis (XPS) and fluorescence microscopy results indicated that PTFEMA were fixed successfully onto the EVA film surface through a covalent bond. During the microalgal adhesion assay, the number of EVA-PTFEMA film-adhered microalgae was 41.4% lower than that of the EVA film. Moreover, the number of microalgae attached to the EVA-PTFEMA film decreased by 61.7% after cleaning, while that of EVA film decreased by only 49.1%. It was found that the contact angle of EVA-PTFEMA film surface increased, and remained stable when immersed in acid and alkali solution for up to 90 days. HIGHLIGHTS: Durable photobioreactor antibiofouling surfaces for microalgal cultivation were prepared successfully. The contact angle of antibiofouling coating surface remained stable in acid and base environment for 90 days. The attached microalgae on antibiofouling surface decreased 41.4% than those of unmodified surface. The attached microalgae on antibiofouling surface could be cleaned by 61.7% through changing the flow velocity of microalgal suspension. [ABSTRACT FROM AUTHOR]

In this work, a new type of composite nanoparticles, 'pearl chain', was developed by linking titanium dioxide and silicon dioxide by polyacrylic acid polymer chains, and the prepared TiO2-PAA-SiO2 composite nanoparticles were analysed by SEM, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and thermogravimetric analysis, zeta potential, x-ray diffraction, etc. The success of this work was verified by the successful linking of TiO2-PAA-SiO2 composite nanoparticles.TiO2-PAA-SiO2 composite nanoparticles were analysed to verify the successful attachment of pearl chains. The obtained TiO2-PAA-SiO2 were subsequently blended in different ratios to prepare polyvinylidene fluoride (PVDF) ultrafiltration membranes. The membrane performance was tested by porosity and water contact angle measurements, scanning electron microscopy, as well as experiments using bovine serum proteins and MTBE interception. The results showed that when a certain amount of TiO2-PAA-SiO2 was added, the surface wettability, porosity and permeability of the prepared modified composite membranes were significantly improved, and the BSA adsorption rate was increased from 71.59% to 80.86%, and the retention rate of MTBE was increased by 77%, in addition to showing a better anti-pollution effect (FRR: 91.07%). It was finally concluded that the prepared membranes embedded with 1.0 wt.% TiO2-PAA-SiO2 nanofillers showed good overall filtration performance, better contamination resistance and remarkable durability. The present work successfully demonstrated the feasibility of using polyacrylic acid chemical chains to connect nanoparticles with different functions to prevent particle loss and substantially enhance membrane performance, which is valuable for bridging connection of composite nanoparticles and exploring the development of high-performance ultrafiltration membranes. [ABSTRACT FROM AUTHOR]

Limited comprehension of differences between tight and loose poplar veneer surfaces affected the bonding performance of carbon fiber (CF)/poplar (P) veneer composites. This study assessed the impact of veneer contact angle variation and hydroxy-methylated resorcinol (HMR) coupling agent treatment on the bonding interface and strength of CF/P veneer composites. Four kinds of epoxy resin-based 3-ply CF/P composite were created: P surface/CF/P surface (SCS), P back/CF/P back (BCB), HMR-treated P surface/CF/HMR-treated P surface (HSCS), and HMR-treated P back/CF/HMR-treated P back (HBCB). Tight surface contact angle was bigger than loose surface angles, and the wettability of loose surface is better than that of tight surface. HMR treatment enhanced epoxy wettability on both sides of veneer, minimizing differences between both sides. After-HMR treatment of veneer, the bonding strength of HSCS group increased notably with 77% higher dry strength and 80% higher wet strength compared to SCS and the peeling rate of HSCS and HBCB was less than 5%. Meanwhile, HMR treatment on veneer effectively balanced epoxy adhesive distribution in bonding interface of CF/P veneer composites and obviously minimized the difference of bondline thickness of the CF/P composite caused by difference between the surface and back of veneer enhancing the bonding strength of the composite. [ABSTRACT FROM AUTHOR]

A large volume of water is bypassing oil and comes up without being able to push it out from the reservoir after organic material adsorption. This work investigates hydrophobicity effect on rock wettability, oil recovery, and relative permeability. The μXRF was used to characterize sand cores, and a contact angle goniometer to determine fluids contact angle. Oil recovery was evaluated by measuring the incremental oil volume recovered in a glass and PVC capillary designed micromodel. Relative permeability was studied using the steady state method, and the wettability was determined by the Amott method. The results show that cores are mainly composed of quartz 86.04%. Oil recovery was 30.50% for oil-wet state; where the wettability index was −0.283. Thereafter, it has been demonstrated that the surfactant solution increases the oil recovery with 23.54 ℅. Adsorption of surfactants on functional groups of PVC change the contact angle between water and PVC's surface from 112° to 39°, decrease the IFT and restore the water-wet state. PVC debris presents efficient new method to determine the water by pass effect on oil recovery. The findings of this study help for better understanding the surfactant-oil displacements during water flooding in light oil reservoirs with impaired wettability. [ABSTRACT FROM AUTHOR]

AbstractLocalized corrosion in steel heat exchangers is a major concern, occurring mostly during operational shutdowns. Due to the absence of flow and moisture content availability, corrosion reduces operation efficiency. A study aimed to optimize the proportions of Zinc and Chromium (Zn-Cr) for developing a hybrid multi-layer electroplating method to inhibit corrosion in hypo-eutectoid carbon steel commonly used in heat exchangers. The Zn-Cr coating was performed using the amperometric method in an electrochemical workstation, producing coatings of varying thicknesses by varying the potential and time. The surface morphology was characterized using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. The average thickness of the Zn-Cr coating was found to be 2.5 µm using the scanning probe microscope analysis. The corrosive action of a standard 3.5% NaCl solution was investigated on both coated and uncoated specimens through open circuit potential measurement and electrochemical impedance spectroscopy. The results indicated that the Zn-Cr coating effectively resisted corrosion. Contact angle measurement of water particles with the Zn-Cr coated specimen revealed a near-super hydrophobic nature with the highest contact angle of 146.8°. [ABSTRACT FROM AUTHOR]

AbstractThe surge in popularity of running has led to a multitude of designs in running shoe technology, notably, there is an increasing trend in toe spring elevation. However, the impact of this design on foot structures during running remains an essential exploration. To investigate the effects of toe spring on the foot during forefoot running, we employed finite element simulation to create two sole models with different toe spring heights (6.5 cm and 8 cm) and ground contact angles (5°, 10°, and 15°). We established and validated two foot-shoe coupling models and compared stress variations in metatarsal bones and the big toe under identical loading and environmental conditions. Higher toe spring resulted in lower peak stress and reduced stress concentration in metatarsal bones. The fourth and fifth metatarsals exhibited increasing stress trends with ground contact angle, with the fifth metatarsal experiencing the most significant stress concentration. In the case of low toe spring, stress on the fifth metatarsal increased from 15.917 MPa (5°) to 27.791 MPa (15°), indicating a rise of 11.874 MPa. Conversely, the first metatarsal showed lower stress, indicating relative safety but reduced functional significance. Moreover, higher toe spring running shoes exerted less pressure on the big toe, with an increasing trend in stress on the big toe with an increase in ground contact angle. Shoes with a higher toe spring design result in reduced pressure on the big toe. Therefore, it is advisable to avoid landing angles greater than 15° to prevent stress fractures resulting from repetitive loading. [ABSTRACT FROM AUTHOR]

Herein, an anionic polymerization method was employed to synthesize a series of amphiphilic poly(ethylene oxide-b-styrene-b-isoprene-b-styrene-b-ethylene oxide) penta-block copolymers (OSISO). Their molecular structure and properties were comprehensively characterized using GPC,1H-NMR, thermodynamic rheological testing and water contact angle test. Notably, the hydrophilic characteristics exhibited a proportional increase with the rise in poly(ethylene oxide) (PEO) content, ranging from 1.3 to 12.6 wt%. The polystyrene blocks with low number-average molecular weight (2000–3500) reduced the copolymer melt viscosity, surpassing a tenfold decrease than the control sample within the temperature range of 50–150 °C. Resultantly, this series of OSISO copolymers could be used to develop amphiphilic hot-melt pressure-sensitive adhesives (HMPSAs) by low temperature hot-melt processing method (<120 °C). HMPSAs loaded with 2 wt% of geniposide, prepared by an optimized composition formula of OSISO copolymers, tackifiers, and plasticizers (in a ratio of 5:5:2), displayed excellent in vitro drug release performance. Additionally, these adhesives presented impressive 180° peeling strength (0.05–0.14 kN/m) without residues left on the substrate in the 180° peeling tests. The incorporation of PEO block significantly enhanced both the adhesive properties and accumulative drug release. Geniposide showed a burst release behavior with a moderate accumulative drug release (15–30 wt%), attributed to the PEO phase without crystallization behavior of long PEO chains. [ABSTRACT FROM AUTHOR]

This study synthesized a series of linear polyurethane elastomers (FTPU) with hydrophobicity and self-healing properties by adjusting the content of Polytetrahydrofuran (PTMEG) and fluorinated polyol (F-OH) as soft chain segments, isophorone diisocyanate (IPDI) and disulfide as hard chain segments. FT-IR, XPS, OM, 3D optical surface profilometer, contact angle tester, SEM, TG, and solvent resistance test were used to characterize its structure and study its self-healing, hydrophobicity, heat resistance, solvent resistance, etc. The results showed that with the increase of F-OH addition, the repair time was shortened and the repair effect was enhanced under the synergistic effect of disulfide bonds and fluorine hydrogen bonds. When the content of F-OH is 50 wt%, the self-healing efficiency is the highest, reaching 94.7%. FTPU can complete self-healing at room temperature (23 ± 2 °C) for 10 h, and self-healing can be completed within 6 min at 100 °C. Second, the introduction of F-OH significantly increased the F content on the surface of FTPU, and the water contact angle of FTPU gradually increased from 70° to 105.5°. More importantly, when FTPU was applied to fabrics, superhydrophobic fabrics with a contact angle of up to 154° were obtained. In addition, FTPU also exhibits excellent thermal stability and solvent resistance, with the T5% of FTPU-3 reaching 331 °C. FTPU has excellent comprehensive performance and can be widely used in various fields such as medical devices, electronic skin, flexible devices, etc. [ABSTRACT FROM AUTHOR]

This study explores the corrosion resistance and antibacterial properties of a PTFE + TiO2/Ag coating applied to 316 L stainless steel. To enhance adhesion, a polydopamine interlayer was chemically deposited onto the steel surface. The PTFE + TiO2 coating was subsequently applied through immersion, followed by the deposition of silver nanoparticles using a chemical method. Optimization of the polydopamine interlayer involved varying temperature, time, stirring speed, and drying parameters. The optimal conditions for the polydopamine interlayer were determined to be 60 °C for 1 h, 300 rpm stirring, and 24-h drying in a freeze dryer. Analytical results demonstrated that both the PTFE + TiO2 and PTFE/PTFE + TiO2/Ag coatings exhibited exceptional corrosion resistance, with corrosion currents of 3.3 × 10−5 and 3.2 × 10−4 μA/cm2, respectively. Antibacterial assessments showcased the remarkable ability of the PTFE/PTFE + TiO2/Ag coating, containing 5% silver content, to effectively inhibit bacterial penetration within a 6.5 mm radius. Furthermore, this coating displayed a water contact angle of 143°, classifying it as a hydrophobic coating. The photocatalytic efficiency (Rs) was determined to be 3.18 × 10−3 A/W, a performance level comparable to that of a standard UV sensor. These findings underscore the substantial enhancements in corrosion resistance, antibacterial performance, and hydrophobic characteristics achieved with the PTFE + TiO2/Ag coating, particularly through the novel optimization of the polydopamine interlayer. This coating exhibits great promise for multifunctional protective applications in diverse fields, particularly demonstrating its suitability for implants and bio-coatings. [ABSTRACT FROM AUTHOR]

The interest in wound dressings increased ten years ago. Wound care practitioners can now use interactive/bioactive dressings and tissue-engineered skin substitutes. Several bandages can heal burns, but none can treat all chronic wounds. This study formulates a composite material from 70% polyvinyl alcohol (PVA) and 30% polyethylene glycol (PEG) with 0.2, 0.4, and 0.6 wt% magnesium oxide nanoparticles. This study aims to create a biodegradable wound dressing. A Fourier Transform Infrared (FTIR) study shows that PVA, PEG, and MgO create hydrogen bonding interactions. Hydrophilic characteristics are shown by the polymeric blend's 56.289° contact angle. MgO also lowers the contact angle, making the film more hydrophilic. Hydrophilicity improves film biocompatibility, live cell adhesion, wound healing, and wound dressing degradability. Differential Scanning Calorimeter (DSC) findings suggest the PVA/PEG combination melted at 53.16 °C. However, adding different weight fractions of MgO nanoparticles increased the nanocomposite's melting temperature (Tm). These nanoparticles improve the film's thermal stability, increasing Tm. In addition, MgO nanoparticles in the polymer blend increased tensile strength and elastic modulus. This is due to the blend's strong adherence to the reinforcing phase and MgO nanoparticles' ceramic material which has a great mechanical strength. The combination of 70% PVA + 30% PEG exhibited good antibacterial spatially at 0.2% MgO, according to antibacterial test results. [ABSTRACT FROM AUTHOR]

The presence of oil-contaminated water due to oil spill disasters or improper industrial waste dumping is now a worldwide danger to both human health and the sustainability of the environment.The use of superhydrophobic materials has attracted considerable attention in the field of oil-water separation, owing to the increasing demand for effective and economical oil-water separation techniques.A new, easy, and inexpensive flame treatment method was used to make a nanocomposite (CuO-SiO2) in order to improve its hierarchical structure (micro-nano).The anodisation process produced copper oxide (CuO) nanostructures (NSs) on a copper mesh. Subsequently, the nanostructures were modified by dip coating with a solution of room-temperature vulcanised silicone rubber (RTV-SR).The coated mesh demonstrated remarkable characteristics of superhydrophobicity and superoleophilicity, with a water contact angle (WCA) of (160 ± 1°) and an oil contact angle (OCA) of (0°), as determined during the measurement of the surface's wetability. The coated mesh surface was characterised using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy dispersive spectroscopy (EDS).The successful separation of kerosene-water and diesel oil-water mixtures is accomplished by using a coated mesh in a simple filtration procedure. Furthermore, it has the capability to separate oils with a high efficiency of (99.8%) for kerosene and (87%) for diesel oil. It also has flux values of (7352.9 L.m-2.h-1) for kerosene and (6112.9 L/m2.h) for diesel. [ABSTRACT FROM AUTHOR]

To promote the application of lignin in Pickering emulsions, the influences of six lignin particles with different hydrophobicity on the emulsifying and stabilizing performances for oil phases with different polarity to form oil in water Pickering emulsions were investigated. The results showed that the best emulsification performance was achieved when the three-phase (oil–water–lignin particle) contact angle was close to 90°. Alkyl-bridged lignin particles with stronger hydrophobicity have a better emulsification effect on cyclohexane with less polarity, while carboxymethylated lignin particles with stronger hydrophilicity have better emulsification effect on n-heptanol with higher polarity. Furthermore, the stability of Pickering emulsions can be improved by appropriately increasing the surface charge and decreasing the particular size of the lignin particles. [ABSTRACT FROM AUTHOR]

In this study, superhydrophobic surfaces were fabricated on aluminium alloy plates with two different experimental procedures using the dip coating method. Each procedure was optimised using the Taguchi design to evaluate the significance of factors such as SiC abrasive paper number, etching time, and chemical modification time. By determining three levels for these factors, the L9 orthogonal array was formed. Water contact angle (WCA) measurements determined the wettability of the surfaces against the water. Scanning Electron Microscopy (SEM) was used to assess the general appearance and roughness of the surfaces. The coating thickness of the surfaces was also measured. For both experimental procedures, the most effective parameter in providing superhydrophobic coatings on the surfaces was determined as the etching time. SEM analyses demonstrated the roughness created by the clustered and protruding structures formed on the surface after the coating. The WCAs above 150° indicate that superhydrophobic surfaces were prepared. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) and polylactic acid (PLA) are among the polymers used in the food industry. In this study, crude extracts of Dunaliella salina were used to treat the surface of 3D printed materials studied, aiming to provide them with an anti-adhesive property against Pseudomonas aeruginosa. The hydrophobicity of treated and untreated surfaces was characterized using the contact angle method. Furthermore, the adhesive behavior of P. aeruginosa toward the substrata surfaces was also studied theoretically and experimentally. The results showed that the untreated PLA was hydrophobic, while the untreated PET was hydrophilic. It was also found that the treated materials became hydrophilic and electron-donating. The total energy of adhesion revealed that P. aeruginosa adhesion was theoretically favorable on untreated materials, while it was unfavorable on treated ones. Moreover, the experimental data proved that the adhesion to untreated substrata was obtained, while there was complete inhibition of adhesion to treated surfaces. [ABSTRACT FROM AUTHOR]

Ever since the discovery of ultra-hydrophobicity in lotus leaf, rigorous experiments have been carried out to replicate and understand its wetting nature using ceramic oxide based coatings on various substrates. Enormous applications dealing with ultra-hydrophobic nature have been explored which led to the discovery of intrinsic hydrophobic nature in rare-earth oxides. Several studies reported intrinsic hydrophobic behavior exhibited by rare earth oxides. Among all rare earth oxides, ytterbium-oxide (Yb2O3) has numerous applications in different fields because of its ability to phase change with pressure, abrasion resistance, high hardness and melting point. This review gives a basic understanding of wettability studies carried out on Yb2O3 coating via the solution precursor plasma spray (SPPS) technique outlined in the literature and aims to understand the mechanism of post-processing treatments, revealing the conditions affecting the reversible wettability. Additionally, the mechanical durability tests performed on thermal-sprayed Yb2O3 coatings are summarized along with the cost-effective approach of SPPS technique over other plasma spray techniques. The ultra-hydrophobicity in Yb2O3 coatings and its existing applications propels the development of novel device-designing strategies in the field of bio-sensing and oil-water separation. [ABSTRACT FROM AUTHOR]

There is an increasing demand for superhydrophobic surfaces due to their unique properties like self-cleaning, anti-icing, corrosion resistance, etc. The development of polyurethane (PU)-based superhydrophobic coating has garnered significant attention for aircraft applications. Polyurethane (PU) topcoat is widely used in aircraft and is hydrophilic in nature with a water contact angle (WCA) of 75 ± 3°. In the present work, a hydrophilic PU clear coat on aircraft-grade aluminum substrate is transformed to a superhydrophobic (SHP) surface by spraying environmentally friendly hydrophobically modified silica nanoparticles (HSiNps) oonto a PU layer that was partially cured in a hot air oven at 60°C for 1.5 h. The SHP surface exhibited a WCA of 162 ± 3° and a sliding angle (SA) of 8 ± 3°. With the incorporation of HSiNps, micro – nano dual-scale surface roughness is created and the surface roughness of the PU coating is increased from 0.35 to 2.42 µm. The coating exhibits good adhesion (5B) with excellent water repelling property and remains thermally stable and superhydrophobic even after subjecting it to 100°C for one week. Durability of the coatings is studied by immersing the coatings in various liquids. The retention of superhydrophobic property after anti-fogging, water sprinkler, and sand paper abrasion tests further demonstrate the robustness of the coating. Polyurethane-based SHP coating is prepared using hydrophobized silica nanoparticles. Partially cured polyurethane coating help in grafting of silica nanoparticles on to the surface. The coatings are durable to heat, solvents, corrosive liquids and sand paper abrasion [ABSTRACT FROM AUTHOR]

Electric discharge machining (EDM) is the most widely used non-conventional machining process for machining difficult-to-cut materials in complex geometries and intricate cavities with less cost. The main problem associated with EDMed part is its increased surface roughness (SR). This article made an attempt on surface modification of Ti6Al4V by reducing SR with different polarities of EDM in deionised water, an eco-friendly dielectric. Experiments were performed on both straight and reverse polarities in full factorial with varying two factors (voltage and current) in two levels. The substrate processed with the reverse polarity possesses minimum (1.26 µm) SR of about 2.15 times than that of the straight polarity (2.64 µm) at the parametric conditions of 60 V, 10 A and 100 µs. Enhanced microhardness (300–450 HV1) and specific wear rate (2.4 × 10−4 mm3/Nm) were observed with the straight polarity due to the microstructural changes along with higher SR and defects. Contact angle analysis reveals that both straight and reverse polarity processed parts are hydrophilic in nature. Reverse polarity can be used as an effective tool for surface modification with less SR and defects and with slight increase in microhardness (300–400 HV1) and specific wear rate (2.6 × 10−4 mm3/Nm). The presence of enriched titanium oxide (rutile) observed on the reverse polarity surface increases its applicability, especially in biomedical industries. [ABSTRACT FROM AUTHOR]

Grinding is one of the most complex techniques of removing material from parts by the countless number of hard and sharp abrasive grains. Grinding creates a substantial amount of heat, which causes surface or subsurface damage, thermal damage, change in the metallographic structure of the material surface. In order to lesson these phenomena, cutting fluids are frequently used in the grinding zone. Minimum Quantity Lubrication (MQL) was suggested as a cost-effective and environmentally friendly lubrication for reducing heat and the expenses of grinding fluid. Despite the fact that MQL plays a crucial role in increasing machining performance, reviews on its use in high-speed machining are conflicted. This review article examines some of the most frequent nanofluids used in MQL systems during grinding processes. Nanofluids in MQL technique are a cutting-edge and eco-friendly approach that substitutes both traditional MQL and flood coolant in the grinding process. The effects of nanofluids on workpiece surface roughness, tangential force, coefficient of friction, G-ratio, grinding specific energy, wheel wear, grinding temperature, workpiece hardness and residual stress are thoroughly discussed and the findings were compared. After reading this review article, one may quickly gain an overview of existing research in the fields of nanofluids. Finally, this study looks at the thermo-physical characteristics of different nanofluids such as contact angle, thermal conductivity, and viscosity. [ABSTRACT FROM AUTHOR]

The membrane contactor application to purify acid gases is a significant advancement in environmental protection and engineering processes. Notwithstanding the numerous privileges of membrane contactors, the wetting of the polymeric membrane is considered the main worry in developing the mentioned technology. The polymeric membrane wetting by liquid absorbents increases the membrane mass transfer resistance and decreases the gas absorption. In this study, hydrophobic PVC membranes including various amounts of CaCO3 nanoparticles were manufactured to reduce the wetting problem. The prepared membranes were evaluated using AFM, TEM, XRD, contact angle, SEM, and tensile strength measurements. The contact angle results illustrated that adding the nanoparticles enhanced the membrane contact angle; so that for nanocomposite membranes comprising 1.5 wt.% nanoparticles, the contact angle increased from about 77°–94°. Investigating the tensile strength results showed that the nanoparticle presence in the membrane structure raised the tensile strength by 10 MPa. Finally, the nanocomposite and pure membrane performance in CO2 absorption was evaluated in the system of membrane contactors. The findings exhibited that after 25 days of the gas absorption process, the permeate flux of pure membranes significantly decreased. However, the gas absorption flux in nanocomposite membranes containing 1.5 wt.% nanoparticles remained constant during this period. [ABSTRACT FROM AUTHOR]

This study evaluates the flotation performance of a novel combination collector, LCJ, on lepidolite from Jiangxi Province, China. A comparative analysis with the on-site collector EO demonstrates an economically efficient separation scheme for lepidolite. Results show that LCJ outperforms EO in capturing lepidolite. Employing 400 g/t sodium hexametaphosphate as an inhibitor and 290 g/t LCJ as a collector, a flotation process with one rougher, two cleaner, and two scavenger stages achieves a lepidolite concentrate with a Li2O grade of 2.10% and a recovery of 78.62%. LCJ also enhances foamability within conventional air-inflation ranges. Infrared testing, Zeta potential analysis, and contact angle measurements indicate similar organic adsorption on the lepidolite surface for both collectors. However, LCJ significantly influences the Zeta potential, increasing hydrophobicity. These findings confirm LCJ as an efficient and selective collector for lepidolite flotation, with promising application prospects. [ABSTRACT FROM AUTHOR]

Offshore and nuclear power plants use titanium condensers to cool exhaust steam from turbines. Preparation of robust superhydrophobic Titanium surfaces is necessary to protect these condensers from fouling and pitting phenomena. This study investigates the impact of various laser-textured Titanium grade 2 surface configurations followed by silicone oil heat treatment on enhancing its wettability and tribological properties. Seven distinct micropatterns were fabricated using a fiber laser with a laser power of 7.5 W, a scanning speed of 300 mm/s, a scan loop of 10, and a pulse frequency of 20 kHz. Patterned surfaces were characterized using different techniques, namely, micro-hardness, surface morphology, wettability, elemental analysis and wear. Improvement in wetting property was observed in laser textured samples after heating with silicone oil due to the adsorption of nonpolar groups (C=O, –CH3) resulting in a low energy surface. The grid pattern surface exhibited the highest water contact angle (WCA) of 151.01° due to a dense microstructure. [ABSTRACT FROM AUTHOR]

AbstractThe majority of treatments are performed with polysulfone (PSf) membranes. The main issue of the PSf membrane is its lack of endothelial function, leading to various processes like platelet adhesion, protein adsorption, and thrombus formation when comes in contact with blood. The crucial aspect in the development of hemodialysis (HD) membrane materials is a biocompatibility factor. This study aims to improve the performance and biocompatibility of PSf membranes by utilizing polyethylene glycol (PEG) as a pore-forming agent and polyacrylamide (PAA) as a multifunctional modifying additive owing to its non-toxic, and biocompatible nature. The formulated HD membranes were characterized using Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and Water Contact Angle (WCA) measurements. The biocompatibility results showed that PSf-PAA membranes reduced the adsorption of bovine serum albumin (BSA) protein, hemolysis process, thrombus formation, and platelets adhesion with improved in vitro cytotoxicity results as well as anticoagulation performance. The protein separation results showed that PSf-PAA membranes were able to reject 90.1% and 92.8% of BSA protein. The membranes also showed better uremic waste clearance for urea (76.56% and 78.24%) and creatinine (73.71% and 79.13%) solutes, respectively. It is conceivable that these modern-age membranes may surpass conventional HD membranes regarding both efficiency and effectiveness. [ABSTRACT FROM AUTHOR]

By using ice slurry generated through a supercooler as storage, it is possible to reduce energy consumption due to high energy density and heat transfer rate along with the phase change. The supercooled water will then be disturbed to create ice crystals in a crystallizer. The main challenge is to prevent the formation of ice in the supercooler since this leads to its blockage. One aim of the European H2020 TRI-HP project is to develop icephobic coatings for supercoolers, that promote high-water supercooling and avoid the formation of ice. In this study, three coatings to prevent or depress freezing in supercoolers are investigated. Specialized equipment for testing freezing on submerged surfaces has been developed, and the results have been correlated to standard surface properties like roughness and contact angle. It was found that the submerged surfaces do not necessarily follow normal icing theory, where freeze depression is related to contact angle. Instead, it is believed that the mobility of surface additives in amphiphilic coatings has an important role. [ABSTRACT FROM AUTHOR]

Nanostructured porous materials are desirable sorbents for separating and removing oil spills from water. This work examines the performance of the prepared efficient sorbents in the oil sorption process. Polyacrylonitrile (PAN) fibers served as the skeleton matrix, while glutaraldehyde and poly(vinyl alcohol) (PVA) served as cross-linking agents. The prepared polymer sorbents showed high adsorption capacity (12.47 g/g), porosity (95.41%) and low density (0.069 g/cm3). The incorporation of carbon nanostructures (nanotubes or graphene oxide) in the sorbent increased the adsorption capacity to 14.85 g/g. The hydrophobic nature of carbon nanotubes significantly increases the contact angle of water with the surface of the nanocomposite absorber and reaches 137.5 degrees. The obtained sorbents showed good reusability in the adsorption process and maintained an adsorption capacity of about 10 g/g after 5 cycles. The optimal temperature range for using nanocomposite sorbents was 25°C to 35°C. The combination of high sorption capacity, low porosity and density in modified polyacrylonitrile, along with its reusability, makes this designed sorbent highly suitable for efficient removal of oil spills. [ABSTRACT FROM AUTHOR]

This article extensively explores moisture resistance treatments for natural fiber-reinforced composites (NFRCs), aiming to mitigate the hindrance posed by their high moisture absorption and limited applications. The study delves into five distinct fiber treatments, emphasizing their roles in improving fiber separation, wettability, homogeneity, and crucial fiber/matrix adhesion by removing surface impurities. Chemical treatments applied are instrumental in inducing hydrophobic behavior in treated fibers, validated by Fourier-transform infrared spectroscopy (FTIR) analysis and an observed increase in water contact angle. Scanning electron microscopy (SEM) analysis underscores the treated NFRCs' superior mechanical properties, showcasing extensive fiber breakage and enhanced energy-dissipating mechanisms. The article employs a 2D finite element (FE) model to visually represent the impact of moisture resistance treatments on NFRCs using the thermal-moisture analogy. Treated samples initially exhibit faster moisture absorption than untreated epoxy, creating a moisture gradient. However, over time, treated NFRCs demonstrate reduced moisture absorption compared to neat epoxy, with the hydrophobic interphase actively attracting and subsequently retarding moisture progression. This comprehensive study identifies effective moisture resistance treatments for NFRCs. It explains their mechanisms, helping to understand how these treatments improve the performance of natural fiber-reinforced composites in practical applications. [ABSTRACT FROM AUTHOR]

To enhance mechanical, adhesive, and thermal properties of Room Temperature Vulcanized (RTV) silicone rubber, a silicon-containing polyurethane/epoxy resin modifier (ESiPU) was developed. A three-phase system of polyurethane/epoxy resin/silicone rubber was prepared through blending, modification, and co-curing. FT-IR and 1H-NMR were employed to characterize the chemical structure of ESiPU. Microscopic analysis revealed improved compatibility between modified epoxy resin and silicone rubber. Mechanical testing showed significant enhancements in tensile strength, elongation at break, and adhesive strength, with RTV-20phr exhibiting increases of 236, 266, and 259%, respectively. Thermogravimetric analysis indicated higher initial decomposition temperature compared to pure RTV. At the same time, the char residue at 800 °C increased to 8.67%. TG-IR analysis demonstrated ESiPU's ability to delay thermal degradation. Contact angle test confirmed improved hydrophobicity. Overall, the developed silicone rubber system exhibits promising mechanical and thermal properties, suggesting potential for aerospace heat protection applications. [ABSTRACT FROM AUTHOR]

Heat exchangers can be coated with functional layers to reduce the negative effects of established fouling films. In the process, long-term layer stability is a requirement for the fouling-inhibiting properties of the surface coatings. Various atomic layer deposition (ALD), with layer thicknesses between 10 and 50 nm, and Parylene (polymeric) coatings, with layer thicknesses < 50 µm, are applied to stainless steel (1.4571) and structural steel (1.0038) substrates. The stability against critical thermal process conditions and cleaning media (acids, alkalis, solvents) is examined. The surface free energy of the substrates is determined before and after durability tests using a contact angle measuring device. In this study the targeted water contact angle was between 80° and 110° and the related surface free energy < 45 mN/m. The change in the surface free energy is a measure of the coating durability. The tested Parylene-coated substrates show no significant changes and no layer defects. In the case of the ALD-coated substrates, only the coating with TiO2 deposition using a chlorine-free precursor shows promising results. Non-systematical layer defects and corrosion can sometimes be optically observed on the TiO2 and Al2O3 ALD-coated substrates. A strong increase in the polar part of the surface free energy is observed. This may be due to the physisorption and chemisorption of water with the coating, increasing polar interactions. In further research, fouling experiments must be performed to investigate the influence of the coatings on the induction time. [ABSTRACT FROM AUTHOR]

The size of bubbles and particle properties (including particle size, density and contact angle) play an important role on the degree of particle loading on bubbles and this has been studied extensively. However, experimental results on the influence of these properties on bubble loading under fluidized-bed flotation conditions (where the probability of detachment is expected to be negligible) are scarce. In this work, the loading fraction (L) of individual bubbles was studied using a high-speed video camera (Phantom Miro LC111). Particles of silica (−75 + 53 µm to −1018 + 850 µm) and magnetite (−425 + 300 µm) were fluidized in a specially designed perspex column. Specific sizes of air bubbles were generated using a combination of a syringe pump and nozzles with different internal diameters. The generated bubbles rose through a bed of fluidized particles, which resulted in bubble loading. The results indicate that fractional bubble loading decreased with an increase in both bubble and particle size. With a 2 mm bubble, the loading fraction of silica declined from circa 0.9 to circa 0.1. However, with coarse particles (−850 + 600 µm and −1018 + 850 µm), bubble loading increased with an increase in bubble size, until an optimum bubble size of 2 mm and then started to decrease as bubble size increased. An increase in particle contact angle showed a corresponding increase in loading fraction, while the density of the material seemed to play no role in terms of the loading fraction. An increase in loading fraction had a negative effect on bubble rise velocity. [ABSTRACT FROM AUTHOR]

Contact angle measurement by sessile drop (SD) and captive bubble (CB) method is calculated by the four software, i.e. 'Angle Tool' plugin, Drop Snake (DS) plugin, and LB-ADSA plugin of the ImageJ®; and the Ossila® with their advantages and disadvantages. In this study, the ease of use and precision were tested by standard deviation calculation for different hydrophilic membranes. Angle Tool plugin, and DS plugin of ImageJ®; and the Ossila software gave high standard deviations due to rough cut membranes edges giving background shadows misleading the software algorithm. LB-ADSA plugin of the ImageJ® had both advantages of manual drop edge selection and algorithmic calculation of contact angle giving the lowest standard deviation. Therefore, we found that the LB-ADSA plugin of ImageJ® is precise for hydrophilic membranes by both SD and CB methods. [ABSTRACT FROM AUTHOR]

Titanium (Ti) implants are widely used in orthopedic and dental applications due to their excellent biocompatibility and mechanical properties. However, bacterial adhesion and subsequent biofilm formation on implant surfaces pose a significant risk of postoperative infections and complications. Conventional surface modifications often lack long-lasting antibacterial efficacy, necessitating the development of novel coatings with enhanced antimicrobial properties. This study aims to develop a novel Ag-TiO2-OTS (Silver-Titanium dioxide-Octadecyltrichlorosilane, ATO) nanocomposite coating, through a chemical plating method. By employing a 'resist-killing-disintegrate' approach, the coating is designed to inhibit bacterial adhesion effectively, and facilitate pollutant removal with lasting effects. Characterization of the coatings was performed using spectroscopy, electron microscopy, and contact angle analysis. Antibacterial efficacy, quantitatively evaluated against E. coli and S. aureus over 168 h, showed a significant reduction in bacterial adhesion by 76.6% and 66.5% respectively, and bacterial removal rates were up to 83.8% and 73.3% in comparison to uncoated Ti-base material. Additionally, antibacterial assays indicated that the ratio of the Lifshitz-van der Waals apolar component to electron donor surface energy components significantly influences bacterial adhesion and removal, underscoring a tunable parameter for optimizing antibacterial surfaces. Biocompatibility assessments with the L929 cell line revealed that the ATO coatings exhibited excellent biocompatibility, with minimal cytotoxicity and no significant impact on cell proliferation or apoptosis. The ATO coatings provided a multi-functionality surface that not only resists bacterial colonization but also possesses self-cleaning capabilities, thereby marking a substantial advancement in the development of antibacterial coatings for medical implants. [ABSTRACT FROM AUTHOR]

Water management is a critical challenge in ensuring the performance and durability of low-temperature proton exchange membrane fuel cells (PEMFCs). This study utilizes the phase-field lattice Boltzmann method to conduct three-dimensional numerical simulations, investigating the dynamics of two-phase flow in the cathode gas channel (GC) of PEMFC with a trapezoidal cross-section. The effects of the water inlet location, the surface wettability of GC, the open angle of GC, and the air velocity on liquid water distribution and discharge are analyzed. The results indicate that positioning the water inlet in the middle of the GC significantly enhances PEMFC performance while having minimal impact on average pressure drop. A wall contact angle of 70° or 110°Can optimize fuel cell performance from different directions. Setting a wall contact angle at 70° optimizes gas flow stability and maintains a low-pressure drop value for the GC. A wall contact angle of 110° focuses on optimizing gas reactant diffusion ability into porous electrodes and GC drainage rate. An opening angle of 55° for the trapezoidal gas channel improves overall fuel cell performance. Increasing air velocity facilitates the film flow formation of liquid water on top wall surfaces within the GC. [ABSTRACT FROM AUTHOR]

AbstractInspired by leaf lotus effect, superhydrophobic surfaces have developed rapidly in recent years. In this paper, anatase nano TiO2 with particles size of about 70 nm was successfully loaded on the surface of SiO2 by sol-gel method. SiO2 and TiO2 were chemically bonded by Ti-O-Si and constructed a certain micro- and nano-composite structure. After superhydrophobic composite PA-TiO2@SiO2 was obtained by copolymerizing with acrylate and other monomers. The coating was prepared by drop coating plus spraying coating on glass substrates with water contact angles >160° and excellent self-cleaning properties, which could maintain the performance of the superhydrophobic coating by immersion in acidic solutions or water for 2 days. Meanwhile, the coating on the surface of the glass plate at −20 °C significantly delayed the freezing time of the ice. The rough structure of the surface and the presence of fluorine-containing hydrophobic groups gave the superhydrophobic coating an advantage over acrylate polymers in reducing the corrosion rate of steel surfaces. [ABSTRACT FROM AUTHOR]

The test polypropylene substrates obtained from the original plastic car parts for Škoda Superb were subjected to 10 pre-treatment techniques: solvent cleaning (isopropanol, xylene), mechanical abrasion, immersion in a chromic acid mixture, flame activation, atmospheric and low-pressure plasma treatment, corona discharges and the application of two different primers (also called adhesion promoters). One of the primers, based on chlorinated polypropylene, was commercially available, while the other was prepared in our laboratory using polypropylene grafted with maleic anhydride. The test substrates were characterized using contact angle measurement for designation of surface free energy, Atomic Force Microscope (AFM) for roughness analysis, Scanning Electron Microscopy (SEM) for surface topography, and Energy Dispersive X-ray Spectrometry (EDX) for surface oxygen and contamination analysis. The suitability of the surface preparation methods in the industry was evaluated through peel strength tests (adhesive bonding process) and cross-cut tests (painting process). Not all tested methods were effective in increasing adhesion, especially in the adhesive bonding process, and even fewer in the painting process. However, some of them were suitable for both applications. The use of primers was found to be crucial. [ABSTRACT FROM AUTHOR]

Currently, due to the industrial development, the direct discharge of large amounts of oil-containing wastewater has led to serious water pollution. It is necessary to develop an efficient, durable, and high-throughput material for oil–water separation. To achieve this, we prepared a nickel (Ni) coating with a loose leaf-like micro/nanostructure on the surface of stainless steel mesh (SSM), imparting it with superhydrophobic and superoleophilic properties. The deposition of ions onto the substrate was carefully controlled by adjusting the deposition parameters. Subsequently, the as-prepared Ni coating was further modified using a solution of perfluorooctyltriethoxysilane (PFOTS) in ethanol to obtain a PFOTS/Ni mesh (PNM) with excellent superhydrophobic–superoleophilic properties. Wettability tests revealed that the water contact angle (WCA) and oil contact angle (OCA) of the PNM, prepared under the optimized deposition conditions, were 161 ± 1° and 0°, respectively, with a water sliding angle (WSA) of less than 10°. Importantly, the PNM demonstrated remarkable mechanical stability in blade scratch and tape peel tests, as well as excellent chemical stability in acid-alkali resistance and electrochemical corrosion tests. And, the PNM exhibited remarkable self-cleaning capability. Additionally, PNMit filters displayed outstanding efficiency in separating oil and water (reaching 91.5%) and remarkable durability. The results indicate that the well-designed superhydrophobic–superoleophilic SSM exhibits advantages such as simple fabrication, low cost, high reusability, and strong robustness. It holds great potential for practical applications in the treatment of oily wastewater and oil spill remediation. [ABSTRACT FROM AUTHOR]

AbstractA series of photoluminescent nanocomposite polyurethane adhesives were elaborated from a chemoenzymatic prepared diol of caprolactone (PCL-diol) and ethylene glycol with an excess of two different isocyanates: i) hexamethylene (HDI) and (ii) isophorone (IPDI)) diisocyanates. Adhesive formulations were filled with functionalized poly(amido-amine) (PAMAM) carbon nanotubes (f-MWNTs) and carbon quantum dots (CQDTs). Dry swine gut was used as substrate and mechanical tests were performed to explore the performance of the adhesives. The obtained materials were characterized by infrared spectroscopy (FT-IR), energy surface by contact angle, differential scanning calorimetry (DSC), hydrolytic degradation, and mechanical testing under tension, lap shear, T-peel, wound closure, and burst pressure. Among the main results were the formation of covalent bonds between the substrate and the adhesive, and the fact that the mechanical strength of the nanocomposite adhesives was superior to that of the unfilled adhesives. Compatibility of nanocomposites with the substrate was achieved by increasing wettability by the incorporation of both nanofillers. Also, adhesives filled with only CQDTs and with MWNTs-CDQTs combined showed photoluminescence activity under ultraviolet light. [ABSTRACT FROM AUTHOR]

AbstractA nanofoam drainage agent was developed to address the challenges of inadequate foam stability and foaming efficiency in the gas recovery process of foam drainage. The formulation of the primary foam drainage agent was obtained by screening and combining conventional anionic and amphoteric surfactants. Experimental results revealed a synergistic interaction between α-olefin sulfonate (AOS) and lauramidopropyl betaine (LAB-35). Specifically, when a mixture of 0.4 wt.% AOS and 0.1 wt.% LAB-35 was used, the surface tension of the primary foam drainage agent was measured to be 23.32 mN/m. Furthermore, modification of Fe3O4 nanoparticles with the silane coupling agent γ-(methacryloxy)propyl trimethoxysilane (KH-570) was performed to improve the dispersibility in aqueous solutions and enhance foam stability. The results of infrared spectroscopy, x-ray diffraction, thermogravimetric analysis, and contact angle measurements revealed the effective bonding of KH-570 to the surface of Fe3O4 nanoparticles. Additionally, the particle size distribution in the aqueous solution showed the excellent dispersion of the modified Fe3O4 nanoparticles. Through the incorporation of the modified Fe3O4 nanoparticles into the primary foam drainage agent, a nanofoam drainage agent with a half-life of 989 ± 6.5 s was developed. Microscopic observations of foam coarsening behavior revealed the mechanism behind foam stability. Performance testing of the foam drainage agent demonstrated the agent’s outstanding resistance against salinity, temperature, and oil and its remarkable liquid-carrying capacity. [ABSTRACT FROM AUTHOR]

Continuous and exclusive use of fenoxaprop-P-ethyl has resulted in serious resistance in Beckmannia syzigachne. Isoproturon, a photosystem II inhibitor, is very frequently used in wheat fields, and there are currently few reports about isoproturon resistance in B. syzigachne. However, excessive use of isoproturon is detrimental to the ecological environment. Therefore, adding additives is a good choice to enhance the effect of isoproturon and reduce its usage. Jijian is a non-ionic and polyhydric alcohol surfactant. Greenhouse whole-plant bioassay results showed that 0.05% (v/v) of Jijian + 600 g ai ha−1 of isoproturon achieved the best synergistic effect on controlling fenoxaprop-P-ethyl-resistant B. syzigachne. Jijian significantly reduced the surface tension and contact angle of the isoproturon solution by 15.8 mN m−1 and 33.2°, respectively, and significantly increased the expanded diameter and maximum retention by 0.92 mm and 8.39 mg cm−2 respectively. In conclusion, Jijian had a synergistic effect on isoproturon in the control of fenoxaprop-P-ethyl-resistant B. syzigachne and Jijian may achieve the synergistic effect by changing the physical properties of isoproturon solution on weeds. [ABSTRACT FROM AUTHOR]

Ni3Al films were deposited on silicon (100) substrate at different substrate temperatures by DC magnetron sputtering. The evolution of phase, microstructure, surface topography and mechanical properties have been investigated as a function of substrate temperature via XRD, FE-SEM, AFM and nanoindentation respectively. Results revealed that the deposited film possessed the preferred orientation of (111) whereas the crystallite size increased and grain size decreased with increase in the substrate temperature. The results of nanoindentation showed that the hardness of the film increased up to 400 °C after which it abruptly decreased. Maximum hardness of ∼13 GPa was achieved when the film was deposited at the substrate temperature of 400 °C. The surface roughness of the film increases simultaneously with the increase in substrate temperature whereas the static contact angle and mechanical properties declined significantly for the film deposited at the substrate temperature of 600 °C. This study reflects the impact of substrate temperature on the evolution of phase, microstructure and mechanical properties of Ni3Al coatings deposited at different substrate temperatures. [ABSTRACT FROM AUTHOR]

In the current investigation, wick parameters of the sintered copper powder in a U-shaped heat pipe, such as particle size, porosity, and contact angle were analysed. The investigations were conducted by cutting the U-shaped heat pipe in axial and radial directions. Then the wick parameters characterisations were conducted that consist of Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-Ray (EDX), and 3D optical microscope. The values of particle size, porosity, and contact angle were then used as parameters in the analytical model to calculate the heat pipe performances. Numerical models were developed to analyse the temperature distribution on the U-shaped heat pipes and validated using the experiments. Based on the analyses, the wick parameters used in the U-shaped heat pipe were obtained: average particles of 70 µm, porosity of 0.16, and contact angle of 20° (day 1). The numerical model shows a good agreement with the experiments. The experimental results suggested that the lowest thermal resistances were 0.21°C/W (natural convection) and 0.11°C/W (forced convection). [ABSTRACT FROM AUTHOR]