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Abstracts: Recently, super gas wet and gas wet surfaces have been extensively attended in petroleum industry, as supported by the increasing number of publications in the last decade related to wettability alteration in gas condensate reservoirs. In many cases, contact angle measurement has been employed to assess the wettability alteration. Even though contact angle measurement seems to be a straightforward approach, there exist many misuses of this technique and consequently misinterpretation of the corresponding results. In this regard, a critical inspection of the most recent updated concepts and the intervening parameters in the contact angle based wettability evaluation of liquid-solid-gas systems could aid to provide some remediation to alleviate this problem. To this end, this work presents a survey on the accurate terms and rigorous protocols based on the community of surface science and chemistry. As a preliminary step, advancing, receding, static, and the most stable contact angle terminology are defined. The study is followed by the definition of the contact angle hysteresis effect. The application of surface free energy in the selection of the best gas wet agent is then analyzed. Afterward, the impact of the size-dependent behavior of drop on contact angle is discussed. Finally, a sessile drop experiment is explained to achieve the defined parameters. For future contributions to petroleum industry journals, like this journal, this work could offer an easy use of the conceptual framework for analyzing the results and comparative evaluations in chemical wettability modifier agents.

In order to obtain the energy change rule in coal adsorbing methane process, methane adsorption experiments were carried out with the temperature of 30 ℃, 15 ℃, 0 ℃, -15℃, -30 ℃, -45 ℃ and the initial adsorption pressure of 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa by the high and low temperature intelligent adsorption experiment chamber. The results show that increasing the gas injection pressure and decreasing the adsorption temperature are two important factors that affect the increase of temperature variation in the process of methane adsorption; the surface free energy of coal samples with a certain mass decreases and the heat increases before and after methane adsorption, and the difference increases gradually due to the increase of methane pressure; in the process of coal adsorbing methane, either pressure boost or temperature drop will increase the coal temperature variation, it is essentially a phenomenon that methane molecular potential energy of coal surface free energy is converted into heat value to maintain the overall energy balance.

The aim of this study is to examine methane (CH4)/nitrogen (N2) gas mixture plasma surface modification for various polymers including in polytetrafluoroethylene (PTFE), polystyrene (PS), polycarbonate (PC), and high-density polyethylene (HDPE). The static wetting properties of methane (CH4)/nitrogen(N2) plasma deposited films on conventional polymers were investigated using the sessile droplet method. The change of hydrophilicity and surface free energy was monitored by static contact angle measurement. The static contact angle is an excellent indication of the change in surface state properties from plasma surface modification. A new quick image-capturing device enables static contact angle measurement 2 to 4 seconds after contact with the polymeric surface. Significant increases in the surface energies of PTFE, PS, PC, and HDPE by CH4/N2 mixture gas plasma treatments were observed. The experimental results show the critical position of chemical species in the interaction between CH4/N2 mixture gas plasma and the polymeric substrate, which can be controlled by surface modification to tailor the hydrophilicity of the polymers. [ABSTRACT FROM AUTHOR]

The surface performance of basalt aggregate shows a great influence on the interfacial adhesion between basalt aggregate and asphalt binder and further affects the moisture stability of the asphalt mixture. To improve the interfacial adhesion between basalt aggregate and asphalt binder, as well as to increase the moisture stability of asphalt mixture in hot and humid environments, the basalt aggregate surface was hydrophobically modified by silane coupling agents (SCAs). Microscopically, the surface properties of basalt aggregate before and after surface modification by SCAs were characterized by environmental scanning electron microscope and Fourier transform infrared spectrometer, as well as the adhesion work between basalt aggregate and asphalt was calculated. Macroscopically, the moisture stability of the asphalt mixture was verified by boiling test and asphalt mixture tests. Test results indicate that the surface free energy values of basalt aggregates modified by SCAs and the stripping work values are decreased. Additionally, silanols, hydrogen bonds, and fibrous protrusions are introduced to the aggregate surface for improving the compactness of the asphalt-aggregate system. Finally, the loss rates of asphalt film and immersion scattering are decreased, as well as the freeze-thaw splitting tensile strength ratio is increased. The hydrophobic surface modification of basalt aggregate can enhance the moisture stability of the asphalt mixture. [ABSTRACT FROM AUTHOR]

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[Display omitted] Interfacial interactions of nanoparticles (NPs) in colloids are greatly influenced by the NP surface free energy (SFE). Due to the intrinsic physical and chemical heterogeneity of the NP surface, measuring SFE is nontrivial. The use of direct force measurement methods, such as colloidal probe atomic force microscopy (CP-AFM), have been proven to be effective for the determination of SFE on relatively smooth surfaces, but fail to provide reliable measurements for rough surfaces generated by NPs. Here, we developed a reliable approach to determine the SFE of NPs by adopting Persson's contact theory to include the effect of surface roughness on the measurements in CP-AFM experiments. We obtain the SFE for a range of materials varying in surface roughness and surface chemistry. The reliability of the proposed method is verified by the SFE determination of polystyrene. Subsequently, the SFE of bare and functionalized silica, graphene oxide, and reduced graphene oxide were quantified and validity of the results was demonstrated. The presented method unlocks the potential of CP-AFM as a robust and reliable method of the SFE determination of nanoparticles with a heterogeneous surface, which is challenging to obtain with conventionally implemented experimental techniques. [ABSTRACT FROM AUTHOR]

The use of ytterbium laser to obtain colored titanium surfaces is a suitable strategy to improve the aesthetic soft tissue results and reduce implant failures in oral rehabilitation. To investigate the relationship between novel laser-colored surfaces and peri-implant soft tissues, Human Gingival Fibroblasts (HGFs) were cultured onto 12 colored titanium grade 1 light fuchsia, dark fuchsia, light gold, and dark gold disks and their viability (MTT Assay), cytotoxicity (lactate dehydrogenase release), and collagen I secretion were compared to the machined surface used as control. Optical and electronic microscopies showed a HGF growth directly correlated to the roughness and wettability of the colored surfaces. A higher viability percentage on dark fuchsia (125%) light gold (122%), and dark gold (119%) samples with respect to the machined surface (100%) was recorded. All specimens showed a statistically significant reduction of LDH release compared to the machined surface. Additionally, a higher collagen type I secretion, responsible for an improved adhesion process, in light fuchsia (3.95 μg/mL) and dark gold (3.61 μg/mL) compared to the machined surface (3.59 μg) was recorded. The in vitro results confirmed the innovative physical titanium improvements due to laser treatment and represent interesting perspectives of innovation in order to ameliorate aesthetic dental implant performance and to obtain more predictable osteo and perio-osteointegration long term implant prognosis. [ABSTRACT FROM AUTHOR]

Erosion and the stripping effect of moisture on asphalt mixtures is one of the main reasons for the shortened service life of asphalt pavements. The common mean of preventing asphalt pavements from being damaged by moisture is adding anti-stripping agents (ASAs) to asphalt mixtures. However, the effect regularity and mechanism of anti-stripping agents on the physicochemical properties of asphalt is not exactly defined. This study compared the physical properties of ASA-modified asphalt (AMAs) to determine the optimal dosage and investigated the rheological and adhesion properties. Based on the roller bottle method and water immersion method, the moisture susceptibility of AMAs with three particle sizes was investigated. The results showed that the modification of asphalt using anti-stripping agents was a physical modification. At the optimum dosage of anti-stripping agents (0.3%), the basic physical properties of AMA1 were the most desirable. ASA2 increased the resistance of asphalt for deformation at high temperature by 46%, and AMA3 had the best low-temperature performance. ASAs enhanced the dispersed and polar components in the asphalt binder, improving the adhesion energy of asphalt. AMA3 had the strongest adhesion to the aggregate, with an increase in adhesion work by 2.8 times and a 45% of increase in ER value. This was attributed to ASA3 containing with a large number of metal cations and polar functional groups. It was shown that ASAs provided the most improvement in the anti-stripping performance of asphalt mixtures with 9.5–13.2 mm particles. The amide ASA, phosphate ASA and aliphatic amine ASA improved the water damage resistance of asphalt by 65%, 45% and 78%, respectively. This study can help engineers realize the effects of different types of ASAs on the physicochemical properties of asphalt and select the most suitable type of ASAs according to the service requirements. [ABSTRACT FROM AUTHOR]

Purpose: The surface properties like roughness, wettability and surface free energy are important for utility properties of traditional and flowable dental restorative composites, due to their role in plaque formation, discoloration, mechanical wear or adhesion and bonding. The goal of our work was to assess the surface free energy (SFE) and the surface roughness (Ra) of three commercial flowable dental composites: everX Flow (bulk), everX Flow (dentin) and Flow-Art. Methods: Surface roughness, contact angle and surface free energy were determined for tested composites. Two surface states (control and roughened) were compared. Roughness was measured with the use of the 3D optical profilometer. The contact angle (CA) was determined through the sessile drop method with the use of four different probing liquids. This enabled to apply two surface free energy approaches (Owens-Wendt (O-W) and van Oss-Chaudhury-Good (LWAB)). Additionally, Zisman's approach (γC) was used. Results: The water contact angle values were similar for Flow-Art (67.56 ± 1.49°) and everX Flow (bulk) (68.94 ± 2.72°) compared to higher value for everX Flow (dentin) (74.39 ± 2.05°). SFE was in the range from 43 to 50 mJ/m² for O-W and from 47 to 62 mJ/m² for LWAB. The γC was from 37 to 45 mJ/m2. Conclusions: Roughening composites' surface influenced on increasing the CA value. All approaches of surface free energy calculations provide useful data for predicting interactions between flowable composites and dental tissues. Tested composites showed good wetting for initial state of surface after polymerization. These influence on better adhesion of the material to the bonding system during dental restoration. [ABSTRACT FROM AUTHOR]

We explore the effects of orange oil adjuvant (a kind of spray adjuvant) on the physicochemical properties of acetamiprid (pesticide) when foliage-applied to the surface of pittosporum tobira leaves. The leaf surface was characterized by the OCG (Van Oss–Chaudhury–Good) method, and the relationship between the wetting behavior of various pesticide droplets, including the change in surface free energy (SFE), adhesion force, and adhesion work, is explored to offer insight into the control of the pittosporum tobira psyllid, Edentatipsylla shanghaiensis Li et Chen. Results showed that SFE values for the adaxial and adaxial leaf surfaces were 40.13 mJ/m2 and 37.06 mJ/m2, respectively, while acetamiprid liquids had SFE values of 67.43 mJ/m2 and 63.26 mJ/m2. SFE values of the acetamiprid liquids are greater than that of the leaf surface, and the droplets on the leaves with a smaller adhesion force and lager adhesion work exhibited moderate-to-poor wettability estimated by contact angles. When the concentration of the orange oil adjuvant was between 0.10% and 1.00% above CMC (critical micellar concentration, 0.09%), the SFE values of the acetamiprid liquids were less than that of the leaf surface. The adhesion tension was greatly increased, and the adhesion work decreased by 14.46–28.13%. Meanwhile, droplets on the leaves exhibited good wettability. Field experiments showed that the synergistic effect of acetamiprid against E. shanghaiensis was significantly improved after spraying with orange oil adjuvant at the concentrations 0.10% and 1.0% above CMC. This study demonstrated the use of an orange oil adjuvant with a concentration above CMC to improve the synergistic effect of the insecticide directly through improved leaf wetting, which can provide reference for reducing pesticide dosage and increasing efficiency during the chemical control of pests. [ABSTRACT FROM AUTHOR]

The frontal part of the Japan Trench plate‐boundary fault is enriched in low‐strength smectite, and this material characteristic is thought to be a factor for the large fault slip during the 2011 Mw 9.0 Tohoku‐oki earthquake. In this study, we evaluated the surface physicochemical properties of the particles that constitute the fault zone and examined their effect on the rheological properties of the fault. Measurements of the zeta potential, surface free energy and pore size distribution indicate that the interparticle interaction in the in situ state is very weak. This means that the viscous resistance is low, which may have contributed to the large fault slip during the earthquake. The interparticle distance appears be longer than the energetically stable state, which may reflect a transitory state after the earthquake. Changes in microscopic interparticle interactions during coseismic and interseismic periods may influence the rheological behaviors of the Japan Trench plate‐boundary fault. Plain Language Summary: Faults in the shallow crust commonly contain abundant clay minerals, and if these clayey faults are saturated with water, then the faults may behave like viscous fluid. The behavior of such fluid is also strongly dependent on interactions between particles in the fluid. In this study, we examine the physicochemical properties of the surfaces of clay particles that constitute the Japan Trench plate‐boundary fault to investigate the interactions between these particles. Our results suggest that such microscopic forces may be one of the factors that control the slip resistance of this fault and its strength recovery process. Key Points: The zeta potential and surface free energy of smectite‐rich fault gouge samples were determined for the Japan Trench plate‐boundary faultThese energies enabled the calculation of interparticle potential under high‐salinity conditions (such as beneath the seafloor)Such microscopic interactions may be the dominant factor in the sliding resistance and strength recovery of the fault [ABSTRACT FROM AUTHOR]

Nickel coatings were fabricated onto the copper substrate by electrodeposition and UV illumination, to obtain long-term stability of the hydrophilic surface. The effect of different fabrication strategies on the surface morphologies was discussed, to reveal the relationship between wettability variation and surface characteristics. The scanning electron microscope, energy-dispersive x-ray spectroscopy, 3D digital microscope and optical contact angle measuring system were adopted to characterize the features of coating surfaces. The results show that the surface morphology, roughness and energy have a significant influence on the variation of surface wettability. The as-prepared coatings were hydrophilic and exhibited high surface free energy. Meanwhile, UV illumination on the virgin coatings led to a slight increase in surface roughness. When exposed to air, the surface with a hemispherical agglomerate structure was more likely to be oxidized and adsorbed airborne organic hydrocarbons, resulting in a significant decrease in surface energy, especially the Lewis acid–base interactions. However, rough surfaces with large pyramid-shaped architecture maintained higher surface energy. After high-temperature aging, the content of carbon elements on the coating surfaces decreased and exhibited better metal lyophilicity. This phenomenon is attributed to organic hydrocarbon particles adsorbed on the surface reacting with the air in a high-temperature environment and then detached from the surface microstructure. This paper provides a method to optimize the surface morphology of nickel coatings on the casting roll, which make the molten metal in a good metal lyophilicity, thus improving the production efficiency of the strip and reducing the production cost. [ABSTRACT FROM AUTHOR]

The interfacial bonding capacity between cement emulsified asphalt composite binder (CEACB) and reclaimed asphalt pavement (RAP) plays a critical role in improving the pavement performance of cold recycled asphalt emulsion mixtures (CRAEMs). This study aims to investigate the formation and development of the interfacial bonding capacity between CEACB and RAP. First, the dynamic wettability and the spreading behaviors of CEACB on RAP surfaces were explored according to the surface free energy theory. Second, digital image processing (DIP) technology was employed to recognize interfacial failure patterns. Lastly, the influence of internal and external factors on the interfacial bonding capacity between CEACB and RAP during the curing process was analyzed via grey relational analysis (GRA). The results indicate that a moderate cement content with a mass ratio of asphalt to cement equivalent to 1.0 can significantly enhance the wettability of CEACB on RAP surfaces. By appropriately prolonging the curing time and controlling the curing temperature, it is possible to increase the bonding strength between CEACB and RAP. Additionally, a strong correlation exists between initial wettability and ultimate bonding capacity during the bonding strength curing process. The good wettability that developed in the initial stage of interfacial strength formation relates to the decreased spalling rate of CEACB on the RAP surface. This study is not only devoted to understanding the mechanisms that can enhance CRAEM performance but also provides important guidance for practical engineering applications of cold recycled asphalt pavements.

Critical supersaturation ratios α crit during epitaxial growth on 6H-SiC (0001) and (000 1 ‾ ) under carbon- and hydrogen-rich conditions were formerly estimated by assuming disc-shaped critical nuclei whose side surfaces were terminated with silicon and carbon atoms, respectively. Since this assumption contradicts the atomic configurations of possible hexagonal-prism-shaped critical nuclei, we evaluated α crit by using the reported surface free energies for hydrogen-passivated 3C-SiC surfaces. To account for the observed α crit being much larger on 6H-SiC (0001) than on 6H-SiC (000 1 ‾ ), we considered that silicon atoms on the side surfaces of hexagonal-prism-shaped critical nuclei be terminated not by carbon but by hydrogen atoms. [ABSTRACT FROM AUTHOR]

Denture cleaners should not be harmful to dental prostheses elements, but immersions in cleaner solutions during a long time of using prosthesis may cause changes on Co–Cr alloy surfaces. There are five classes of denture cleaners: alkaline hypochlorites, alkaline peroxides, disinfectants, diluted acids, and enzymes. The aim of this work was to evaluate the influence of denture cleaners solutions on the surface properties of Co–Cr alloy.

Starch-based materials seem to be an excellent alternative for conventional plastics used in various applications. Microfibralted cellulose can be used to improve the surface properties of starch-based materials. This study aims to analyze the surface properties of starch-microfibrillated cellulose materials. The surface properties of films were evaluated by ATR-FTIR, surface roughness, water wettability, and surface free energy. The surface homogeneity between corn starch and microfibrillated cellulose (MFC) fibers was confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Microscopic analyses of the film surfaces confirm good compatibility of starch and MFC. The addition of MFC increased the surface roughness and polarity of developed starch/MFC materials. The surface roughness parameter has increased from 1.44 ± 0.59 to 2.32 ± 1.13 for pure starch-based materials and starch/MFC material with the highest MFC content. The WCA contact angle has decreased from 70.3 ± 2.4 to 39.1 ± 1.0°, while the surface free energy is 46.2 ± 3.4 to 66.2 ± 1.5 mJ·m−2, respectively. The findings of this study present that surface structure starch/MFC films exhibit homogeneity, which would be helpful in the application of MFC/starch materials for biodegradable packaging purposes. [ABSTRACT FROM AUTHOR]

Wood surface roughness, surface free energy (SFE), wettability, and bonding quality for water-based acrylic coatings were investigated. The samples tested in this study included Pinus radiata, Pinus sylvestris, Larch, Hemp oak, Catalpa tree, and Camphor. Sandpaper with grits of 180, 240, 320, 400, and 500 was utilized to sand wood surfaces. The van OSS-Chaudhury-Good equation (vOCG) was used to calculate the SFE values. The modified model (M-D) was used to calculate the wettability based on the contact angle change rate (K value). The higher the K value, the faster the contact angle approaches equilibrium. A cross-cut test was used to evaluate the coating's bonding quality. The anatomical structure of wood has an impact on the roughness of hardwood. The equilibrium contact angle is influenced by the wood species and sandpaper grit size. Sanding can make the surface of wood more wettable. Radiata pine that had been sanded to 180 grit had the highest SFE value. After finishing with waterborne acrylic, hardwood had a slightly better coating adhesion than softwood. Hemp oak wood had the lowest coating adhesion (0.6) and the highest K value (0.82). The best bonding quality (0.4) was supplied by the camphor wood with the lowest K value (0.13). Wettability in terms of K values was a good indication of determining the bonding quality of the water-based acrylic coatings. [ABSTRACT FROM AUTHOR]

Hydrophobic surface with satisfactory resistance to ultraviolet (UV) radiation plays a vital role in sol–gel porous antireflective (AR) coatings. In this work, sol–gel hydrophobic silica AR coatings were prepared by modifying the surface of nanoparticles with fluorine-free organosilanes (hexamethyldisilazane, hexadecyltrimethoxysilane, and N-octyltrimethoxysilane) or fluorine-containing silanes (1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane and 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane). The UV resistance of the coatings grafted with different hydrophobic groups was studied through monitoring the changes in wettability and optical properties of the coatings before and after UV irradiation. In addition, the evolution in the surface characteristics of the coatings after UV irradiation was evaluated by studying their surface morphology and chemical composition. Based on the contact angle results, the surface free energy (SFE) of the coatings before and after UV irradiation was estimated and compared. After UV irradiation, the SFE of fluorine-free organosilane-modified silica coatings increases dramatically, whereas the coatings modified with the fluoroalkyl silanes still maintain very low SFE. The high bond energy of C−F provides a particularly high degree of resistance to UV light damage, which imparts the long-chain fluoroalkyl-grafted POTS/SiO2 and POTCS/SiO2 coatings with superior UV resistance. The fluorine-containing organosilane modification provides an effective way to simultaneously integrate high transparency and excellent UV resistance for hydrophobic silica coatings. Highlights: The UV resistance of different hydrophobic silica antireflective coatings was studied. The fluorine-containing organosilane-modified silica coating exhibits combined advantages of high transparency, UV resistance, and hydrophobicity. The surface of fluorine-free organosilane-modified silica coating changes from hydrophobic to super-hydrophilic. [ABSTRACT FROM AUTHOR]

The use of modern materials in sports, in terms of chemical composition and surface texture, entails both progress in results and an increasing discrepancy in the technical parameters of the equipment used. This paper aims to demonstrate the differences between balls admitted to a league and world championships in composition, surface texture, and the influence of these parameters on the water polo game. This research compared two new balls produced by top companies producing sports accessories (Kap 7 and Mikasa). To obtain the goal, the measurement of the contact angle, analysis of the material using Fourier-transform infrared spectroscopy, and optical microscopic evaluation were used. The analysis of the surface free energy shows significant differences (Kap 7 32.16 mJ/m2, Mikasa 36.48 mJ/m2). In the case of both balls, anisotropies of the structure of the furrows were observed, however, the Mikasa ball is slightly more homogeneous than the Kap 7 ball. The obtained results from the analysis of the contact angle, as well as the composition and real feedback from the players, indicated the need to standardize the material aspect of the regulations so that the sports results are repeatable every time. [ABSTRACT FROM AUTHOR]

The purpose of this study was to characterize physicochemical properties and investigate anti-bacterial adhesion effect of dental resins containing fluorinated monomers. Fluorinated dimethacrylate FDMA was mixed with commonly used reactive diluent triethylene- glycol dimethacrylate (TEGDMA) and fluorinated diluent 1 H,1 H-heptafluorobutyl methacrylate (FBMA) separately at a mass ratio of 60 wt./40 wt. to prepare fluorinated resin systems. Double bond conversion (DC), flexural strength (FS) and modulus (FM), water sorption (WS) and solubility (SL), contact angle and surface free energy, surface element concentration, and anti-adhesion effect against Streptococcus mutans (S. mutans) were investigated according to standard or referenced methods. 2,2-bis[4-(2-hydroxy-3-methacryloy-loxypropyl)-phenyl]propane (Bis-GMA)/TEGDMA (60/40, wt./wt.) was used as control. Both fluorinated resin systems had higher DC than Bis-GMA based resin (p < 0.05); compared with Bis-GMA based resin (FS, FDMA/TEGDMA resin system had higher FS (p < 0.05) and comparable FM (p > 0.05), while FDMA/FBMA resins system had lower FS and FM (p < 0.05). Both fluorinated resin systems had lower WS and SL than Bis-GMA based resin (p < 0.05), and FDMA/TEGDMA resin system had the lowest WS (p < 0.05) in all experimental resin systems. Only FDMA/FBMA resin system showed lower surface free energy than Bis-GMA based resin (p < 0.05). When the surface was smooth, FDMA/FBMA resin system had lower amount of adherent S. mutans than Bis-GMA based resin (p < 0.05), while after the surface became roughness, FDMA/FBMA resin system had comparable amount of adherent S. mutans as Bis-GMA based resin (p > 0.05). Resin system prepared exclusively with fluorinated methacrylate monomers reduced the S. mutans adhesion due to their increased hydrophobicity and decreased surface energy., while flexural properties of it should be improved. [ABSTRACT FROM AUTHOR]

New linear and cross-linked polyurethanes with cycloaliphatic units and renewable cross-linkers (Span 20 and Tween 20) were obtained by two steps polyaddition reaction. The degree of microphase separation was calculated by FTIR-ATR spectroscopy with higher values for the linear polyurethane with the highest hard segment content (0.88) and lower values for the cross-linked polyurethane with Tween 20 as crosslinker (0.35). The results were in accordance with the DSC analysis. The linear or cross-linked character of the polyurethane structure influenced the thermal, mechanical, and surface properties. The obtained polyurethanes had good thermal stability, with a 5% mass loss at 321°C (HMC 1) and 329°C (HMC 2) for linear polyurethanes and 330°C (HMC 3) and 342°C (HMC 4) for the cross-linked ones. The morphology and wettability of the cycloaliphatic polyurethanes presented different behavior depending on the amount of the hard segment content and also the chemical structure of the cross-linker. Linear polyurethanes were characterized by a globular morphology and hydrophobic character, while the use of Tween 20 as cross-linker led to a fibrillar morphology with a low water contact angle (62°). Mechanical measurements showed that all polyurethanes present elastomeric behavior with high tensile strength values for the linear polyurethanes (33 MPa for HMC 1 and 39 MPa for HMC 2) and lower values of tensile strength for the cross-linked ones (12 MPa for HMC 3 and 11 MPa for HMC 4), but high elongation at break for all samples (780%-1100%). [ABSTRACT FROM AUTHOR]

High molecular weight chitosan (HMWCh), quaternised cellulose nanofibrils (qCNF), and their mixture showed antiviral potential in liquid phase, while this effect decreased when applied to facial masks, as studied in our recent work. To gain more insight into material antiviral activity, spin-coated thin films were prepared from each suspension (HMWCh, qCNF) and their mixture with a 1:1 ratio. To understand their mechanism of action, the interactions between these model films with various polar and nonpolar liquids and bacteriophage phi6 (in liquid phase) as a viral surrogate were studied. Surface free energy (SFE) estimates were used as a tool to evaluate the potential adhesion of different polar liquid phases to these films by contact angle measurements (CA) using the sessile drop method. The Fowkes, Owens–Wendt–Rabel–Kealble (OWRK), Wu, and van Oss–Chaudhury–Good (vOGC) mathematical models were used to estimate surface free energy and its polar and dispersive contributions, as well as the Lewis acid and Lewis base contributions. In addition, the surface tension SFT of liquids was also determined. The adhesion and cohesion forces in wetting processes were also observed. The estimated SFE of spin-coated films varied between mathematical models (26–31 mJ/m2) depending on the polarity of the solvents tested, but the correlation between models clearly indicated a significant dominance of the dispersion components that hinder wettability. The poor wettability was also supported by the fact that the cohesive forces in the liquid phase were stronger than the adhesion to the contact surface. In addition, the dispersive (hydrophobic) component dominated in the phi6 dispersion, and since this was also the case in the spin-coated films, it can be assumed that weak physical van der Waals forces (dispersion forces) and hydrophobic interactions occurred between phi6 and the polysaccharide films, resulting in the virus not being in sufficient contact with the tested material during antiviral testing of the material to be inactivated by the active coatings of the polysaccharides used. Regarding the contact killing mechanism, this is a disadvantage that can be overcome by changing the previous material surface (activation). In this way, HMWCh, qCNF, and their mixture can attach to the material surface with better adhesion, thickness, and different shape and orientation, resulting in a more dominant polar fraction of SFE and thus enabling the interactions within the polar part of phi6 dispersion. [ABSTRACT FROM AUTHOR]

A correct silanization time is essential for successful surface functionalization and sufficient bonding to dental ceramics. The shear bond strength (SBS) of lithium disilicate (LDS) and feldspar (FSC) ceramics and luting resin composite was investigated with respect to different silanization times, taking into account the physical properties of the individual surfaces. The SBS test was performed with a universal testing machine, and the fracture surfaces were evaluated by stereomicroscopy. The surface roughness of the prepared specimens was analyzed after etching. Changes in surface properties due to surface functionalization were evaluated by surface free energy (SFE) via contact angle measurement. Fourier transform infrared spectroscopy (FTIR) was used to determine the chemical binding. The roughness and SBS of the control group (no silane, etched) were higher for FSC than for LDS. Regarding the SFE, the dispersive fraction increased and the polar fraction decreased after silanization. FTIR confirmed the presence of silane on the surfaces. The SBS of LDS showed a significant increase from 5 to 15 s, depending on the silane and luting resin composite. For FSC, cohesive failure was observed for all samples. For LDS specimens, a silane application time of 15 to 60 s is recommended. Based on clinical conditions, no difference between the silanization times was observed for FSC specimens, indicating that etching alone produces sufficient bonding. [ABSTRACT FROM AUTHOR]

Activated carbon fibers (ACFs) as one of the most important porous carbon materials are widely used in many applications that involve rapid adsorption and low-pressure loss, including air purification, water treatment, and electrochemical applications. For designing such fibers for the adsorption bed in gas and aqueous phases, in-depth comprehension of the surface components is crucial. However, achieving reliable values remains a major challenge due to the high adsorption affinity of ACFs. To overcome this problem, we propose a novel approach to determine London dispersive components ( γ S L ) of the surface free energy of ACFs by inverse gas chromatography (IGC) technique at an infinite dilution. Our data reveal the γ S L values at 298 K for bare carbon fibers (CFs) and the ACFs to be 97 and 260–285 mJ·m−2, respectively, which lie in the regime of secondary bonding of physical adsorption. Our analysis indicates that these are impacted by micropores and defects on the carbon surfaces. Comparing the γ S L obtained by the traditional Gray's method, our method is concluded as the most accurate and reliable value for the hydrophobic dispersive surface component of porous carbonaceous materials. As such, it could serve as a valuable tool in designing interface engineering in adsorption-related applications. [ABSTRACT FROM AUTHOR]

The microbiological behavior of dental polymer materials is crucial to secure the clinical success of dental restorations. Here, the manufacturing process and the machining can play a decisive role. This study investigated the bacterial adhesion on dental polymers as a function of manufacturing techniques (additive/subtractive) and different polishing protocols. Specimens were made from polyaryletherketone (PEEK, PEKK, and AKP), resin-based CAD/CAM materials (composite and PMMA), and printed methacrylate (MA)-based materials. Surface roughness (Rz; Ra) was determined using a laser scanning microscope, and SFE/contact angles were measured using the sessile drop method. After salivary pellicle formation, in vitro biofilm formation was initiated by exposing the specimens to suspensions of Streptococcus mutans (S. mutans) and Streptococcus sanguinis (S. sanguinis). Adherent bacteria were quantified using a fluorometric assay. One-way ANOVA analysis found significant influences (p < 0.001) for the individual parameters (treatment and material) and their combinations for both types of bacteria. Stronger polishing led to significantly (p < 0.001) less adhesion of S. sanguinis (Pearson correlation PC = −0.240) and S. mutans (PC = −0.206). A highly significant (p = 0.010, PC = 0.135) correlation between S. sanguinis adhesion and Rz was identified. Post hoc analysis revealed significant higher bacterial adhesion for vertically printed MA specimens compared to horizontally printed specimens. Furthermore, significant higher adhesion of S. sanguinis on pressed PEEK was revealed comparing to the other manufacturing methods (milling, injection molding, and 3D printing). The milled PAEK samples showed similar bacterial adhesion. In general, the resin-based materials, composites, and PAEKs showed different bacterial adhesion. Fabrication methods were shown to play a critical role; the pressed PEEK showed the highest initial accumulations. Horizontal DLP fabrication reduced bacterial adhesion. Roughness < 10 µm or polishing appear to be essential for reducing bacterial adhesion. [ABSTRACT FROM AUTHOR]

Poly(ethylene terephthalate)—PET—is one of the most frequently used polymers in biomedical applications. Due to chemical inertness, PET surface modification is necessary to gain specific properties, making the polymer biocompatible. The aim of this paper is to characterize the multi-component films containing chitosan (Ch), phospholipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), immunosuppressant cyclosporine A (CsA) and/or antioxidant lauryl gallate (LG) which can be utilized as a very attractive material for developing the PET coatings. Chitosan was employed owing to its antibacterial activity and also its ability to promote cell adhesion and proliferation favorable for tissue engineering and regeneration purposes. Moreover, the Ch film can be additionally modified with other substances of biological importance (DOPC, CsA and LG). The layers of varying compositions were prepared using the Langmuir—Blodgett (LB) technique on the air plasma-activated PET support. Then their nanostructure, molecular distribution, surface chemistry and wettability were determined by atomic force microscopy (AFM), time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), contact angle (CA) measurements and the surface free energy and its components' determination, respectively. The obtained results show clearly the dependence of the surface properties of the films on the molar ratio of components and allow for a better understanding of the coating organization and mechanisms of interactions at the molecular level both inside the films and between the films and the polar/apolar liquids imitating the environment of different properties. The organized layers of this type can be helpful in gaining control over the surface properties of the biomaterial, thus getting rid of the limitations in favor of increased biocompatibility. This is a good basis for further investigations on the correlation of the immune system response to the presence of biomaterial and its physicochemical properties. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of an ultraviolet (UV) curable coating material on denture base resin. The results of the three-point bending test showed no significant difference between treated and untreated specimens, suggesting that the UV curable coating material did not compromise the physical strength of denture base resin. The surface free energy measurement and the surface analysis with atomic force microscopy revealed superhydrophilicity and a regularly arranged structure on the coating surface, improving wettability. Moreover, untreated specimens were significantly discolored in the staining test. However, specimens treated with the UV curable coating material showed no significant difference in color with slight staining, suggesting excellent antifouling ability. Therefore, the UV curable coating material used in this study could contribute to simplifying hygiene without altering the physical properties of denture base resins. [ABSTRACT FROM AUTHOR]

Wettability is an important parameter of micro/nanostructured composites. The measurement of apparent contact angle is strongly affected by surface roughness, which induces some challenges to study the intrinsic hydrophobicity correlating to the nature of chemistry. Carbon‐Nafion composites exhibited about 30° decrease in apparent contact angle from 30 to 10°C due to the condensation of water vapor into cavities, suggesting a significant Cassie–Wenzel wetting transition phenomenon. The focus of this work has been on the first‐time use of a low‐T Cassie–Wenzel wetting transition method to evaluate Young's (ideal) contact angle and surface free energy. A maximum Young's contact angle (113°) and minimum total surface energy (12 mJ/m2) were determined at Nafion content of 70 wt%, indicating the orientation effect that sulfonate groups in Nafion preferentially pointed toward polar carbon. This approach provided the reasonable prediction of intrinsic hydrophobicity, especially when a rough solid surface is not easily wetted by liquids. [ABSTRACT FROM AUTHOR]

The present study investigates how varying negative micro-pillar densities on H13 alloy, used in hot-forming dies, affect wettability with different fluids and tribological performance, alongside detailed morphological analysis. Recast materials, pockmarks, micro-voids, micro-cracks, and globules of debris are observed on EDM textured surfaces, and challenges are form accuracy and debris entrapment with higher textured density. The functional stressed surfaces, evident from XRD analysis, display hydrophobic properties with water and hydrophilic characteristics with mineral-oil-based emulsion. Increased texture density enhances these properties. Wettability properties transition of fabricated functional surfaces occurs within fluid surface energies of 48 to 72.8 mN/m. The coefficient of friction (COF) of the lower-density patterned surface is 20.42 % lower than the untextured surface, and the higher-density pattern shows a 13.48 % COF reduction compared to the lower-density surface. Key wear mechanisms include abrasion, adhesion, sharp edges and adhered debris deformation, and localized plastic deformation for untextured and textured surfaces. [Display omitted] ● Investigating varying densities of negative micro-pillar textured H13 surfaces on wettability and tribological performance. ● The form accuracy of large-area micro-textured surfaces from form tools is explored. ● Fabricated functional surfaces demonstrate fluid-dependent wetting properties. ● Textured patterns significantly reduced COF and wear rate with increased texture density. [ABSTRACT FROM AUTHOR]

The aim of this research was to analyze the interfacial properties between the surfaces of mechanically and electrochemically treated aluminium substrates and the printed coatings modified by the addition of silicon dioxide (SiO 2) and titanium dioxide (TiO 2) nanoparticles. The nanoparticles were added to the printing inks in various concentrations with the scope to optimize the interface properties of the prints for outdoor applications. The surface, as well as the structural and mechanical properties of the printed coatings were evaluated. Various methods were employed to measure and analyze the surface and interfacial properties of aluminium and coatings. Surface microphotographs and the roughness of the treated aluminium substrates were examined, the surface free energy of the aluminium and the coatings as well as the adhesion properties were calculated, and the thickness and optical density of the coatings were measured. Considering that the treated aluminium samples prepared for this research had quite textured and different surfaces, the contact angles used for the calculation of surface free energy were calculated with and without Wenzel model to obtain detailed information about the interactions between the surface of aluminium samples and the printed modified coatings. The results showed that the type of treatment of aluminium substrates as well as the modification of the printing inks have a significant influence on the adhesion and surface properties of the coatings considered. Furthermore, the results demonstrated that the produced nano-modified coatings can be used as printed coatings or as customized primers for applying various types of inks and coatings. [ABSTRACT FROM AUTHOR]

Fiber metal laminates (FMLs) have been proposed as components of structural batteries, yet their elastic mismatch can lead to interface cracks, compromising structural integrity and both mechanical and electrochemical efficiency. To this end, the bonding between the metal and the composite layer is of utmost importance. In this study, the effect of various metal surface treatments on the mode I interlaminar fracture toughness of two FML configurations suitable for structural batteries — Glass Fiber Reinforced Polymer (GFRP)/aluminum laminate and GFRP/copper laminate — was examined. The surface treatments included sulfo-ferric etching, NaOH/HNO 3 etching, and Sol–Gel anodizing for aluminum 2024-T3, as well as FeCl 3 /HCl/Glycerol treatment and Sol–Gel anodizing for copper alloy. The results were compared with untreated conditions and with the baseline GFRP/GFRP configuration. GFRP/metal coupons were designed to achieve pure mode I interlaminar fracture toughness in double cantilever beam (DCB) tests, and the designs were verified using the Virtual Crack Closure Technique (VCCT). The surface characterization of the metals was performed using contact angle tests to estimate the surface free energy, while Coherence Scanning Interferometry (CSI) was used to measure the surface roughness and topography. [ABSTRACT FROM AUTHOR]

This paper investigates if the polar groups induced by a plasma treatment can increase the lap shear strength of laser-joined metal and plastic hybrids. Optimal laser joining parameters for cold-rolled AISI304–polyamide 6.6 and sandblasted AISI304–polypropylene hybrids were developed at 2.85 MPa and 4.22 MPa, respectively. The surface free energy was doubled for all used plasma gases to a value of ca. 80 mN m−1 at 180 s. The plasma-treated samples were joined and tested. The arithmetic means of the plasma-treated hybrids’ lap shear strength with polyamide 6.6 varied slightly, but all measured values were within the range of the untreated samples. Residue on the sheared metal samples indicated covalent bonds between AISI304 and polyamide 6.6. The lap shear strengths of the plasma-treated polypropylene hybrids were significantly reduced between −30.8% and −53.3%, depending on the used plasma gas. This was attributed to the over-aging and development of low-molecular-weight oxidized materials, which led to a weak boundary layer. No residue of polypropylene was found on treated or untreated lap shear samples. No correlation between the surface free energy and lap shear strength could be found.

Water-in-oil (w/o) nanoemulsions stabilized with amino acid surfactants (AAS) are one example of nanotechnology detergents of the "brush on, wipe off"-type for removing graffiti coatings from different sensitive surfaces. The high-pressure homogenization (HPH) process was used to obtain the nanostructured fluids (NSFs), including the non-toxic and eco-friendly components such as AAS, esterified vegetable oils, and ethyl lactate. The most effective NSF detergent was determined by response surface methodology (RSM) optimization. Afterwards, several surface properties, i.e., topography, wettability, surface free energy, and the work of water adhesion to surfaces before and after their coverage with the black graffiti paint, as well as after the removal of the paint layers by the eco-remover, were determined. It was found that the removal of graffiti with the use of the NSF detergent is more dependent on the energetic properties and microporous structure of the paint coatings than on the properties of the substrates on which the layers were deposited. The use of NSFs and knowledge of the surface properties could enable the development of versatile detergents that would remove unwanted contamination from various surfaces easily and in a controlled way. [ABSTRACT FROM AUTHOR]

In this study, the chemical state change of recycled carbon fiber (rCF) surfaces and the mechanism of the oxygen functional groups according to nitric acid treatment at various times and temperatures were investigated to upcycle the carbon fiber recovered from used carbon composite. When treated with nitric acid at 25 °C, the carbon fiber surface demonstrated the same tensile properties as untreated carbon fiber (CF) for up to 5 h, and the oxygen functional group and polar surface energy of C–O (hydroxyl group) and C=O (carbonyl group) increased slightly compared to the untreated CF up to 5 h. On the other hand, at 100 °C, the tensile properties slightly decreased compared to untreated CF up to 5 h, and the amount of C–O and C=O decreased and the amount of O=C–O (lactone group) started to increase until 1 h. After 1 h, the amount of C-O and C=O decreased significantly, and the amount of O=C–O increased rapidly. At 5 h, the amount of oxygen functional groups increased by 92%, and the polar surface energy increased by 200% compared to desized CF. It was determined that the interfacial bonding force increased the most because the oxygen functional group, O=C–O, increased greatly at 100 °C and 5 h. [ABSTRACT FROM AUTHOR]

Chemical and thermal modification can change the hydrophilic properties of wood, and thus affect their coating performance. This study determined the surface characteristics of chemically and thermally modified short rotation teak wood. The characteristics studied were surface roughness, surface free energy (SFE), contact angle, wettability, and coating bonding quality. Results show that the surface of short rotation teak became smoother after chemical and thermal modifications; however, surface roughness increased after furfurylation. The total SFE of chemically and thermally modified teak wood decreased after treatment. The decrease in the total SFE caused the decrease in the constant contact angle change rate (K-value). The K-values for water-dispersed polyurethane and acrylic paints were nearly 0, which indicated their lower wettability. The paint bonding quality decreased after accelerated weathering. Short rotation teak with Glycerol-Maleic Anhydride (GMA)-thermal treatment can be considered for exterior applications with a proper selection of paint. [ABSTRACT FROM AUTHOR]

Obtaining high-water-yield drinking water in arid areas without consuming energy is still a global challenge. Since water vapor is ubiquitous, atmospheric water harvesting technologies are undoubtedly one of the most promising candidates. A typical water condensation process is analyzed in this paper (nucleation, self-growth, coalescence and sliding). The mechanisms of interactions between adsorbate and water vapor are discussed. The effect of surface-free energy and microstructure on water vapor condensation is described. Finally, the main problems in developing more efficient, high-water-mass and high-cycle-stability atmospheric water collectors are summarized, and the future development trend has been prospected. [ABSTRACT FROM AUTHOR]

The surface free energy of wood is an important property that influences later manufacturing process, such as wood gluing and finishing. Sodium silicate modifications of poplar wood inevitably alter wood's surface free energy. The purpose of this study was to determine the effect of various impregnation times on the resulting surface free energy of radial and tangential sections of poplar wood specimens. The contact angles of standard probe liquids (i.e. distilled water, diiodomethane, formamide) on the surface of the wood were measured by contact angle goniometer, and a geometric average method and acid–base interaction method were applied to calculate and analyze the changes in the surface free energy. In addition, Fourier transform infrared spectroscopy was used to analyze the changes in the functional groups on the wood surface; after finishing the wood surface with water-based or oil-based paint, the paint film adhesion properties were also evaluated. The results indicate that sodium silicate modification can effectively improve the surface wettability and surface free energy of poplar wood. The modification treatment gradually creates hydrophilic groups (e.g. hydrogen bonds, free hydroxyl groups) on the wood surface, and their contents increase with increasing impregnation time. Additionally, by introducing Si-O–C moieties, the polarity, dispersion, and acid–base components of the wood surface all increase to varying degrees. Finally, the sodium silicate modification treatment worsens the adhesion of the paint films on the wood surface, although not to a significant extent. [ABSTRACT FROM AUTHOR]

The wettability and surface free energy of diamonds are crucial for their applications. In this study, polycrystalline boron-doped diamond (PBDD) films with different boron doping concentrations were prepared, and the effect of the boron doping concentration on the wettability and surface free energy (SFE) of the film was investigated. The SFEs of the PBDD films were investigated by employing the surface tension component approach and the equation-of-state approach. The investigation suggested that the alternative formulation of Berthelot's rule, the Lifshitz-van der Waals/acid-base (van Oss) approach, and the Owens-Wendt-Kaelble approach were suitable for estimating the SFEs of PBDD films, whereas the Fowkes approach, Berthelot's (geometric mean) combining rule, and Antonow's rule could not provide reliable results. Results showed that the SFEs of PBDD films increased with increasing boron doping concentration, and the SFEs were 43.26–49.66 mJ/m2 (Owens-Wendt-Kaelble approach), 42.89–52.26 mJ/m2 (Lifshitz-van der Waals/acid-base), and 44.38–48.73 mJ/m2 (alternative formulation of Berthelot's rule). This study also provides a reference for the application of empirical and physics-based semi-empirical approaches to SFE estimation. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the polar and dispersive surface free-energy (SFE) components of the central layer of corrugated paperboards, which are made of recycled fibres. The polar and dispersive components of, and the total, SFE (also known as interfacial energy) were calculated from the contact angles of water and diiodomethane liquids on recycled cellulose sheets. The total SFE of the middle component layers of two different grammages which comprised recycled fibres ranged from 47.9 mN/m to 51.05 mN/m. The contribution of the polar component to the total surface free energy of the two types of sheets ranged from 8.6 mN/m to 12.6 mN/m. This polar contribution was significantly lower than that of water. The contact angle method proved to be a consistent way to estimate the surface properties of industrially made recycled paper products. [ABSTRACT FROM AUTHOR]

Plywood usage has been increasing recently in the building and furniture industry due to its outstanding surface and resistance properties. Although it has many advantages, the flammability of plywood needs to be improved with fire-retardant chemicals. However, these chemicals which improve panels against burning can be differently influenced many properties of panels. This study aimed to investigate the surface roughness, wettability, and surface free energy of the veneers treated with some fire-retardant chemicals and to determine the changes in the mechanical properties of plywood. The beech, poplar, alder, and pine veneers were used as wood species whilst zinc borate, borax, monoammonium phosphate, and ammonium sulfate were used as fire-retardant chemicals in this study. The surface roughness and contact angle measurements were performed to determine the surface properties of veneers, and then the surface free energy values were calculated. The bonding and bending strength of the plywood panels produced from these veneers were determined according to the relevant standards. As a result of the study, the surface free energy values of veneers with lower contact angles and smoother surfaces were found to be higher. It was also determined that the bonding strength values of plywood panels produced from veneers with high surface energies were also high. Generally, the untreated veneers had higher surface free energy values than the treated veneers. Among the fire-retardant chemicals, zinc borate caused the highest surface free energy values in the beech and alder veneers while borax exhibited the highest values in the poplar and pine veneers. [ABSTRACT FROM AUTHOR]

We formulated and experimentally proved a hypothesis on the causes of dispersion (puffing and microexplosion) of binary fuel droplets, including those in the composition of gel fuels. This hypothesis is based on the concepts of wetting thermodynamics and the theory of the two-component surface energy of substances and materials. An effective and reliable criterion was established that allowed the assessment of the possibility of the onset of puffing and microexplosion during the high-temperature heating of binary liquids. Microexplosions were found to occur only when isothermal conditions were necessarily reached at the liquid–liquid interface during the mixing of mutually insoluble components, provided that one component had to be polar, and the second had to be dispersive. In addition, it was necessary to provide external heating conditions under which the value of the surface free energy of the liquid–liquid interface formation tended to zero. [ABSTRACT FROM AUTHOR]

Graphene has become an intensive research field of study in the material science due to its peculiar properties and various applications. Particularly, it is considered as the thinnest 2D material, which is used widely in many devices, and hence, this involves its interaction with supporting substrates; thus, free surface energy of graphene is very essential for its miscellaneous application in our life. Here, in this report, we present the measuring results of static contact angle of microscale liquid droplets adsorbed on graphene-coated copper and silicon substrates at room temperature to calculate the graphene surface free energy and its wettability. Both copper- and silicon-coated substrates increase the static water contact angle values, indicating hydrophobicity of graphene layers. On the other hand, variation of strength of aqueous ionic solution, sodium chloride solution, does not change the static water contact angle, indicating minor importance of polar component of surface free energy of graphene layers. For few layers of graphene, up to three, the graphene surface free energy is controlled by the Cassie state, while for more than three layers, the surface exhibits the Wenzel state of wetting. [ABSTRACT FROM AUTHOR]

Warm Mix Asphalt (WMA) technology can effectively reduce carbon emissions and energy consumption during road project construction. However, it may have a negative impact on the binding properties of asphalt mixtures. In order to effectively evaluate the adhesion performance of asphalt binders and aggregates under the combined influence of WMA and traditional polymer-modified asphalt, this paper provides a comprehensive evaluation at the micro and macro levels. The adhesion between three different modified asphalts (warm mix crumb rubber/ Styrene-Butadiene-Styrene (SBS) composite modified asphalt, warm mix crumb rubber asphalt, and warm mix SBS modified asphalt) and two different aggregates (limestone and granite) under both virgin and short-term aging conditions were analyzed. Regardless of the type of modified asphalt, the results showed that limestone aggregates have better adhesion properties with asphalt binders. In addition, the short-term thermal oxidation aging behavior is conducive to enhancing the asphalt-aggregate adhesion characteristics. Furthermore, WMA additives, crumb rubber, and SBS compound modification can improve the adhesion performance between asphalt and aggregate. [ABSTRACT FROM AUTHOR]

Indium tin oxide (ITO) is one of the most widely used semiconductor among transparent conducting oxides (TCOs) due to their electrical conductivity and optical transparency properties. Since the development of low temperature deposition methods, coating of ITO on polymer substrates especially for use in flexible electronics has been a popular topic. The existence of adequate adhesion strength between ITO and polymer is critical in producing a successful film. Nowadays, polycarbonate (PC), poly(methyl methacrylate) (PMMA) and polyethyleneterephtalate (PET) are frequently used as substrates for such coatings. However, there may be other polymeric alternatives that have a potential to be used for this purpose in the future. To evaluate these alternatives, work of adhesion (Wa ) knowledge between ITO and polymers is necessary, and it has not been handled systematically previously. In this study, the interphase interaction parameters and Wa values between ITO and various polymers were calculated based on the Dupré, Fowkes and GirifalcoGood equations. PC, PMMA, PET, polystyrene (PS), polyphenylene sulfide (PPS), Nylon 66, polypropylene (PP), polyvinylchloride (PVC), styrene-butadiene rubber (SBR), high density polyethylene (HDPE), low density polyethylene (LDPE), polyvinyl acetate (PVAc), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polytrifluoroethylene (PTrFE) and polyperfluoroalkylethyl acrylate (PPFA) were considered as substrate material. Surface free energy (SFE) components calculated by acid-base, geometric mean and harmonic mean approaches for polymeric substrates were used during the calculations. In the present study, the polymers that can be used as substrates were evaluated in terms of adhesion ability to ITO, the significance of calculation methods on Wa values were also investigated simultaneously. It was determined that the Wa between ITO and polymer substrates was directly related with the total SFE value of the polymers. [ABSTRACT FROM AUTHOR]

Many sites with high solar radiation like MENA regions face high dust loads that reduce the efficiency generation of solar plants. In this context, this paper provides an overview of dust adhesion mechanism on the surfaces of concentrated solar power (CSP) mirrors. The assessment of dust adhesion was performed on the hydrophilic/hydrophobic glasses at two representative CSP locations in Morocco (Ouarzazate and Midelt). Two types of reflecting mirrors are examined. The first one is based on superhydrophilic TiO2 protective coating, and the second one is the reflector mirror based on hydrophobic Al2O3 protective coating. The research shows that for particle radius of 2 µm, the Van der Waals force dominates for hydrophobic coating for Midelt with high humidity. In contrast, the capillary forces are prominent on the superhydrophilic TiO2 coating for Ouarzazate with low humidity. The results show good agreement with the X-ray diffraction results. However, as compared to Midelt dust, the dust particles from Midelt are formed of Smectites for the clay fractions. Smectite is highly swelling clay in water compared with Illite, Kaolinite, and Vermiculites types of clay minerals (low swelling clay in water). This work provided a facile method for the calculus of adhesion forces on the surfaces of CSP mirrors and as result helps us to select the best types of anti-soiling coating for reflector mirrors. [ABSTRACT FROM AUTHOR]