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This study tests biodegradation resistance of a custom synthesized novel ethylene glycol ethyl methacrylate (EGEMA) with ester bond linkages that are external to the central polymer backbone when polymerized. Ethylene glycol dimethacrylate (EGDMA) with internal ester bond linkages and EGEMA discs were prepared in a polytetrafluoroethylene (PTFE) mold using 40 μl macromer and photo/co-initiator mixture cured for 40 s at 1000 mW/cm(2). The discs were stored in the constant presence of Streptococcus mutans (S. mutans) in Todd Hewitt Yeast + Glucose (THYE+G) media up to 9 weeks ([Formula: see text] for each macromer type) and physical/mechanical properties were assessed. Initial measurements EGEMA versus EGDMA polymer discs showed equivalent degree of conversion (45.69% ± 2.38 vs. 46.79% ± 4.64), diametral tensile stress (DTS; 8.12± 2.92 MPa vs. 6.02 ± 1.48 MPa), and low subsurface optical defects (0.41% ± 0.254% vs. 0.11% ± 0.074%). The initial surface wettability (contact angle) was slightly higher [Formula: see text] for EGEMA (62.02° ± 3.56) than EGDMA (53.86° ± 5.61°). EGDMA showed higher initial Vicker’s hardness than EGEMA (8.03 ± 0.88 HV vs. 5.93 ± 0.69 HV; [Formula: see text]). After 9 weeks of S. mutans exposure, EGEMA ([Formula: see text]) showed higher resistance to biodegradation effects with a superior DTS than EGDMA ([Formula: see text]) [Formula: see text]. Visible and scanning electron microscopy images of EGEMA show less surface cracking and defects than EGDMA. EGDMA had higher loss of material (18.9% vs. 8.5%, [Formula: see text]), relative changes to fracture toughness (92.5% vs. 49.2%, [Formula: see text]) and increased water sorption (6.1% vs. 1.9%, [Formula: see text]) compared to EGEMA discs. The flipped external ester group linkage design is attributed to EGEMA showing higher resistance to bacterial degradation effects than an internal ester group linkage design methacrylate.

Thrombosis is an important factor that causes the failure of artificial biological valves in addition to calcification and immune rejection. A hydrophobic antifouling surface can improve blood compatibility by reducing the absorption of protein. In this study, porcine pericardium was cross-linked with glycidyl methacrylate, and carbon-carbon double bonds were introduced. Then, fluoride monomer was added so that the pericardial surface would become hydrophobic and antifouling. Fluoride modification changed the hydrophilicity of the pericardium surface, and the surface water contact angle increased from 84° to 143°. Compared with unmodified pericardium, the adsorption of bovine serum albumin and fibrinogen decreased by 93.1% and 85%, respectively, and the anti-thrombogenicity was greatly enhanced.

The unique characteristics of polyether ether ketone (PEEK) including low elastic modulus, high mechanical strength, and biocompatibility have made it an attractive alternative for the metallic biomaterials. However, its bioinert property is always the main concern, which could lead to poor osseointegration and subsequent clinical failure of the implant. Changing the surface structure to porous structure and mixing it with bioactive hydroxyapatite (HA) are the common methods, which could be used to enhance the properties of the PEEK-based implants. In this study, friction stir processing was utilized for the fabrication of porous HA/PEEK surface nanocomposite. Scanning electron microscopic image of the nanocomposite surface showed nano-scale roughness of the porous structure. Water contact angle test confirmed the increase in the wettability of the treated specimens. In vitro bioactivity test via simulated body fluid solution, initial cell adhesion, cell proliferation, and cell differentiation assay also confirmed the enhancement in bioactivity of the treated surface in comparison to the bare PEEK. This surface modification method requires no special equipment and would not damage the heat-sensitive PEEK substrate due to the low temperature used during the fabrication process.

Rose petals may involve high water contact angles together with drop adhesion which are antagonistic wetting properties. Petal surfaces have a cuticle which is generally considered a continuous, hydrophobic lipid coating. The peculiar properties of rose petals are not fully understood and have been associated with high surface roughness at different scales. Here, the chemical and structural features of natural upper and lower petal surfaces are analyzed by atomic force microscopy (AFM). Both rose petal surfaces are statistically equivalent and have very high roughness at all scales from 5 nm to 10 μm. At the nanoscale, surfaces are fractal-like with an extreme fractal dimension close to df = 2.5. A major nanoscale variability is also observed which leads to large (nanoscale) wettability changes. To model the effect of roughness and chemical variability on wetting properties, a single wetting parameter is introduced. This approach enables to explain the Rose petal effect using a conceptually simple scheme. The described fundamental mechanisms leading to high contact angles together with drop adhesion can be applied to any natural and synthetic surface. Apart from introducing a new approach for characterizing a biological surface, these results can trigger new developments on nanoscale wetting and bio-inspired functional surfaces.

This study aimed to evaluate the influence of sterilization methods on conventional and bulk-fill resin composites' (BFRCs) surface properties in an attempt to preview bias in laboratory bacterial adhesion tests. Two regular viscosity conventional resin composites [Filtek Z350 XT™ (Z350) and IPS Empress Direct™ (ED)] and two regular viscosity BFRCs [Filtek Bulk Fill™ (FILT) and Tetric N-Ceram Bulk Fill IVA™ (TBF)] were used. The materials were characterized by Scanning Electron Microscopy (SEM), surface roughness (SR), and wettability (W) after sterilization with hydrogen peroxide gas plasma (HPGP) and steam sterilization (SS). Nonsterilized samples served as a control group (n = 5). Statistical analysis was performed using two-way analysis of variance (ANOVA) and Tukey post hoc test (p 0.05). For SR, there were no statistically significant differences among the groups (p .05). SS method decreased the contact angle for FILT and Z350 (p .01). The SS promoted more exposition of filler particles, while the HPGP method did not alter the tested materials' morphology. Therefore, sterilization methods affected the resin composites tested selectively. HPGP seems to be the most recommended method to sterilize the tested resin composites before laboratory bacterial adhesion tests.

The purpose of this study was to clarify the impact of protein carbonylation on the chemical characteristics of the hair surface focusing on hydrophobicity.First, we examined the validity of methods to evaluate hydrophobicity, one that utilizes the fluorescence of 1-anilinonaphtalene-8-sulfonic acid (1,8-ANS) compared with the contact angles against HThe fluorescence intensity of 1,8-ANS of the hair surface modified chemically correlated well with the contact angles against HThe results suggest that the carbonylation of proteins at the hair surface with aldehydes decreases hydrophobicity and promotes further damage as does bleaching.OBJECTIF: l’objectif de cette étude était de clarifier l’impact de la carbonylation des protéines sur les caractéristiques chimiques de la surface des cheveux en se concentrant sur l’hydrophobicité. MÉTHODES: nous avons d’abord examiné la validité de la méthode d’évaluation de l’hydrophobicité, une méthode qui utilise la fluorescence de l’acide 1-anilinonaphtalène-8-sulfonique (1,8-ANS) par rapport aux angles de contact avec l’H2O, de la surface des cheveux chimiquement modifiés par hydrolyse alcaline ou traités par chlorure d’ammonium stéarylique. Nous avons mesuré la fluorescence provenant du 1,8-ANS, l’angle de contact et les modifications des groupes fonctionnels, aldéhydes (le degré de carbonylation), NH2, COOH et SH des cheveux décolorés à l’H2O2 ou traités par acroléine, à l’aide de méthodes de marquage par fluorescence. RÉSULTATS: l’intensité de la fluorescence du 1,8-ANS de la surface des cheveux modifiés chimiquement était bien corrélée aux angles de contact avec l’H2O. Les résultats ont indiqué que le 1,8-ANS était adapté à l’évaluation de l’hydrophobicité de la surface des cheveux. L’hydrophobicité des cheveux décolorés à l’H2O2 ou carbonylés à l’acroléine a diminué. De plus, les modifications des groupes fonctionnels des cheveux carbonylés par l’acroléine ont augmenté, tout comme celles des cheveux décolorés à l’H2O2. CONCLUSION: les résultats suggèrent que la carbonylation des protéines à la surface des cheveux par des aldéhydes diminue l’hydrophobicité et favorise d’autres dommages, tout comme la décoloration.

Rapid and sensitive point-of-care testing (POCT) is an extremely critical mission in practical applications, especially for rigorous military medicine, home health care, and in the third world. Here, we report a visual POCT method for adenosine triphosphate (ATP) detection based on Taylor rising in the corner of quadratic geometries between two rod surfaces. We discuss the principle of Taylor rising, demonstrating that it is significantly influenced by contact angle, surface tension, and density of the sample, which are controlled by ATP-dependent rolling circle amplification (RCA). In the presence of ATP, RCA reaction effectively suppresses Taylor-rising behavior, due to the increased contact angle, density, and decreased surface tension. Without addition of ATP, untriggered RCA reaction is favorable for Taylor rising, resulting in a significant height. With this proposed method, visual sensitive detection of ATP without the aid of other instruments is realized with only a 5 μL droplet, which has good selectivity and a low detection limit (17 nM). Importantly, this visual method provides a promising POCT tool for user-friendly molecular diagnostics.

In this study, the simultaneous significance of the crystallographic texture and nanostructuring on the cytocompatibility of as-cast (Ti55 Zr25 Nb10 Ta10 )98.5 -Ag1.5 alloy (at. %, TZNT-Ag1.5 ), subjected to cold rolling up to 90% reduction, along with the changes of Young's modulus and hardness under cold rolling were investigated. For this purpose, the as-cast and cold-rolled TZNT-Ag1.5 alloy test specimens were analyzed by XRD, TEM, HRTEM, SEM, contact angle, nanoindentation, and OM techniques. Moreover, to evaluate the effect of severe cold deformation on the biocompatibility, MG-63 osteoblastic cell was cultured on the surface of 90% cold-rolled and as-cast test specimens of TZNT-Ag1.5 alloy. The results showed that severe cold deformation was led to fast grain refinement of β grains of the as-cast TZNT-Ag1.5 alloy in the range of 50-100 nm. In addition to the nanostructuring, upon severe cold deformation, the -fiber ( // normal direction) texture was formed and after 90% reduction, the (111) 1 ¯ 0 > γ-fiber component was strengthened. The micro-hardness and reduced Young's modulus are 235 ± 5.29, 246 ± 1.73, 271 ± 4.0, and 283 ± 6.25 (HV); and 73.725 ± 1.70, 83.98 ± 5.10, 81.26 ± 6.55, and 88.66 ± 7.16 (GPa) for TZNT-Ag1.5 (as-cast), TZNT-Ag1.5 (20%CR), TZNT-Ag1.5 (50%CR), and TZNT-Ag1.5 (90%CR) test specimens, respectively. Further, with increasing the cold deformation degree, the dislocation density of TZNT-Ag1.5 alloy increased as this parameter is 2.79 × 1015 (m-2 ) for the 90%CR test specimen. On the other hand, the values of the contact angle for the 90%CR test specimen (46.2 ± 3.5°) exhibit a higher hydrophilic and wettable surface as compared to the other studied test specimens. After 5 days of incubation, osteoblastic cells on the surface of the 90% cold-rolled TZNT-Ag1.5 test specimens revealed significant differences in cell proliferation and differentiation as compared to the as-cast alloy test specimens and/or CP-Ti. Finally, because the maximum orientation intensities were generally

BACKGROUND Different thermoplastic starch (TPS) films were prepared with or without the addition of microcrystalline cellulose (MCC) obtained via the melt-extrusion method, and then the hot-press method was used to produce environmentally friendly TPS-based film/paper composites to replace petroleum-based materials. RESULTS The paper-plastic composites exhibited good interfacial adhesion from the scannign elctron microscopy images. It was seen that 5 wt.% MCC was added to reinforce the mechanical properties of TPS films, such that it also improved the barrier properties of MCC@TPS/paper composites and extended the path of water vapor through TPS films, which decreased the water vapor transmission rate of MCC@TPS/paper composites. TPS/paper composites and MCC@TPS/paper composites have better physical properties (i.e. smoothness, flexibility and folding resistance) than only paper. In particular, it was found that the water contact angle of MCC@TPS/paper composites and TPS/paper composites were higher than single-layer paper. Furthermore, MCC reinforced paper-plastic composites demonstrated good barrier properties which can meet the requirement of the need for lower water sensitive materials in the food packaging industry. CONCLUSION Thermoplastic corn starch-based film/paper composites have good application properties as a potential source of bioplastic materials. © 2021 Society of Chemical Industry.

BACKGROUND Because of the high surface/volume ratio in nanometric size particles, they exhibit novel functional properties in many industries, such as emulsion stabilization. Tragacanth nanoparticles (TNPs) were prepared in this research, applying intense ultrasound energy followed by anti-solvent precipitation in ethanol. RESULTS Investigation of wettability showed a contact angle of 88.9 ± 1.7° for TNPs, providing partial wetting of the nanoparticles at the oil-water interface. Pickering emulsions were prepared using TNPs at different oil contents. Also, emulsions containing tragacanth gum solution were prepared as control emulsions. Results showed that the viscosity of the emulsions prepared by the TNPs was significantly lower than those of the control emulsions. Microscopic images showed that the size of the emulsion droplets decreased by increasing the nanoparticle concentrations. Evaluation of the stability of the emulsions showed that changes in the average diameter of the emulsion droplets stabilized by nanoparticles were not significant after 1 month of storage at room temperature. In contrast, the size of the droplet of control emulsions increased over the 30 days of storage. Thermal and mechanical stresses confirmed the effect of the concentration of TNPs and the oil ratio on the stability of the emulsions. CONCLUSION The use of TNPs as a natural biopolymer is a promising approach in emulsion systems to prevent coalescence and increase the stability of the Pickering emulsions. © 2021 Society of Chemical Industry.

This review summarizes the results of cold atmospheric pressure plasma technology application in polymers surface treatment. Attention is given to results of changes in the hydrophilic property of polymer surfaces by incorporation of polar functional groups when exposed to atmospheric pressure plasma, depending on the time of treatment, applied voltage, gas flow rate, and distance from the surface. We have successfully developed a plasma device that is able to generate cold atmospheric pressure argon plasma of low temperature (20 – 26) ° C downstream using a high-voltage power source which can be widely used in materials processing. Therefore, a cost-effective system of generating a plasma jet at atmospheric pressure with potential applications has been developed. Cold atmospheric pressure plasma jet (CAPPJ) has shown a lot of applications in recent years such as in materials processing, surface modification, and biomedical materials processing. CAPPJ has been generated by a high voltage (0-20 kV) and high frequency (20-30 kHz) power supply. The discharge has been characterized by optical and electrical methods. In order to characterize cold atmospheric pressure argon plasma jet, its electron density, electron temperature, rotational temperature, and vibration temperature have been determined using the power balance method, intensity ratio method, Stark broadening method, and Boltzmann plot method, respectively. The improvement in hydrophilicity of the cold plasma-treated polymer samples was characterized by contact angle measurements, surface free energy analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Contact angle analysis showed that the discharge was effective in improving the wettability of polymers after the treatment. Furthermore, atmospheric plasma can be effectively used to remove surface contamination and to chemically modify different polymer surfaces. The chemical changes, especially oxidation and cross-linking, enhance the surface properties of the polymers.

Superhydrophobicity is a property of surfaces characterized by extreme water repellence and it is observed in highly textured low surface energy materials. The surface roughness can be varied widely. There are several ways by which superhydrophobicity can be achieved on various kinds of surfaces. Polymer surfaces have a wide range of applications and are a good candidate for making superhydrophobic surfaces. Superhydrophobic surfaces are well known for their self-cleaning and anti-icing properties so that water droplets roll off the surface taking away all the external contaminant particles that are present on the surface along with it. Surfaces that have a static water drop contact angle of greater than 150° and a roll-off angle of less than 10° can be termed as superhydrophobic surfaces. The various methods for making superhydrophobic surfaces that have been developed are templating, lithography, plasma treatment, electrochemical deposition, layer-by-layer self-assembly, sol-gel deposition, wet chemical reaction, hydrothermal reaction, chemical vapor deposition, and electrospinning. Many physical and chemical methods have been used to design and fabricate superhydrophobic surfaces. However, surfaces are prone to damage by scratches, abrasion, or even brief contact with fingers, and, therefore, surfaces might lose their superhydrophobicity. Hence, improving mechanical robustness and self-replenishment of superhydrophobic surfaces upon damage is an active area of research. Potential applications of superhydrophobic surfaces include biomaterials, microelectronics, microfluidics, coatings, textiles, and so on. Various superhydrophobic surfaces have been discussed in this paper, namely poly(dimethylsiloxane), polytetrafluoroethylene, etc., and their applications.

Marine facilities and ships are easily plagued by biofouling. Synergistic surfaces combining surface reactive ion etching and peptide modification were designed and prepared to tackle surface biofouling. Six microstructural surfaces were first designed and machined based on the contact point theory; the synergistic surfaces were then prepared by peptide modification. Laser confocal scanning microscope (LCSM), scanning electron microscopy (SEM), contact angle measurement, and X-ray photoelectron spectroscopy (XPS) were utilized to analyze the surface morphology and surface chemical properties; the results demonstrated that six synergistic surfaces were prepared successfully with 0.8-mu m depth, surface contact angle increased from 75 degrees to 116.99 degrees, and the surface chemical compositions were also changed significantly due to peptide modification. Antibiofilm assays showed that surface modification and surface topology could slightly reduce the formation of biofilm. While the synergistic surfaces possess strong anti-algal performance, and anti-Chlorella pyrenoidosa (C. pyrenoidosa) and anti-Phaeodactylum tricornutum (P. tricornutum) rates reached 78.56% and 87.80%, respectively after 7-day immersion in artificial seawater. Compared with the single surface treatment method, the antifouling performance of the synergetic surfaces were stronger. This strategy demonstrated a realistic paradigm for the further improving surface antifouling performance in a green method.

Background The wettability of the target surfaces affects the wetting and deposition of pesticides on them. The properties of leaf surfaces change after infestation by Tetranychus urticae Koch. Studying the surface wettability of T. urticae and the changes in leaf wettability after infestation is important to guide the use of acaricides. Results The body surface of T. urticae is an ellipsoidal crown covered with dense cuticle striations and hairs arranged in different directions, which makes the surface of T. urticae rough and hydrophobic. The abaxial surfaces of the leaves are rougher and more hydrophobic than the adaxial surfaces. After infestation by T. urticae, the faded spots were sunken on the adaxial surface and raised on the abaxial surface, where they had formed new wide peaks and valleys. The adaxial surface became obviously rougher and more hydrophobic, while the roughness of the abaxial surface became slightly larger, and the change in hydrophobicity was not obvious. The contact angles of the studied commercial acaricide on these surfaces were greater than 65° and were affected by the infestation. Reducing the surface tension can allow for better wetting of these surfaces and eliminate changes in leaf wettability. Conclusion The surfaces of kidney bean leaves became more hydrophobic after infestation by T. urticae with hydrophobic surface. The wettability of the acaricide solution should be adjusted according to the changes in leaf wettability. This study has important theoretical guiding significance for improving effective deposition of acaricide.

Much effort has made to lessen the cytotoxicity and enhance the corrosion resistance of biodegradable magnesium alloys, for example, by depositing multilayered polymeric coatings containing hydroxyapatite. In this work, a hierarchical structure composed of ciprofloxacin (Cip)-loaded on polyacrylic acid (PAA) and poly (ethyleneimine) (PEI) as biocompatible polymeric multilayers and calcium phosphate coating as the top layer is formed by the sol-gel method on the AZ91 Mg alloy with an intermediate layer formed by nitrogen plasma immersion ion implantation. The thicknesses of the multilayered coating and nitrided layer (Mg3 N2 ) are 10 μm and 140 nm, respectively. The corrosion current density decreases by 95.6% and the corrosion potential in the polarization curve shifts to the positive direction by 23%. The passivation process which occurs at defects by deposition of corrosion products mitigates both galvanic and localized corrosion. Slight increase in the contact angle and surface free energy, enhanced corrosion resistance, and reduced cytotoxicity are observed from the multilayered structure. The better corrosion resistance enables better control of release of Cip. Biological assessment indicates that the antibacterial activity against Escherichia coli is improved by 100% after culturing for 24 hr and the cell viability and noncytotoxic behavior of the coated AZ91 are enhanced as well. The corrosion behavior and biological results suggest that the strategy of using a hierarchical structure composed of Cip-loaded polymeric multilayers in conjunction with an intermediate plasma nitrided layer has large potential in the development of biodegradable orthopedic implants made of Mg alloys.

Polypropylene (PP) mesh is most commonly used for the treatment of hernia and pelvic floor construction. However, some of the patients have a few complications after surgery due to the rejection or infection of the implanted meshes. The poor biocompatibility of PP mesh, low wettability results in poor cell attachment/proliferation and restricts the loading of antibacterial agent, leading to a slow healing process and high risk of infection after surgery. Here in this study, a new technique has been employed to develop a novel antimicrobial and biocompatible PP mesh modified with bioactive chitosan and functionalized nanodiamond (FND) for infection inhibition and acceleration of the healing process. An oxygen plasma treatment PP mesh was used then chitosan was strongly attached to the surface of the PP fibers. Subsequently, FND as an antibacterial agent was loaded into the chitosan modified PP fiber to provide desired antibacterial functions. The meshes were characterised with XRD, FTIR, SEM, EDX, water contact angle, confocal, and optical microscopy. The modified PP mesh with chitosan and FND showed a significant increase in its hydrophilicity and L929 fibroblast cell attachment. Furthermore, the modified mesh exhibited great antibacterial efficiency against Escherichia coli. Therefore, the newly developed technique to modify PP mesh could be a promising technique to generate a biocompatible PP mesh to accelerate the healing process and reduce the risk of infection after surgery.

BACKGROUND Understanding performance matching of pesticide droplets on the surface of cucumber leaves modified by powdery mildew is of practical importance for the agricultural sector. Here, the surface texture and wettability of cucumber leaves covered by powdery mildew were systematically examined using parameters such as micromorphology, physicochemical properties, and liquid droplet contact angle measurements. RESULTS Our results show that powdery mildew growth can be divided into four distinct stages according to the surface texture characteristics of the diseased cucumber leaves. The three-dimensional (3D) surface structures of powdery mildew layers on cucumber leaves had individual characteristics at different mildew growth stages, among which powdery mildew was more easily spread in the last growth stage, and powdery mildew height was greatest in the NO. 2 growth stage (Sa = 425.35 μm). Surface free energy values, static contact angle, and contact angle hysteresis all correlated strongly with the surface characteristics of powdery mildew layers at different growth stages. When the concentration of surfactant reached the critical micelle concentration, the wetting state of AEO-5 solution droplets on the surface of cucumber powdery mildew leaves reached the Wenzel state more easily. The wettability of a droplet on the leaf surface depends on the state of the monomer and micelle in the surfactant solution and the surface characteristics of the powdery mildew-covered leaf. CONCLUSION The 3D structure and relative dielectric constant of powdery mildew-covered leaves influenced surface texture characteristics, which in turn controlled the wetting and matching ability of surfactant droplets on diseased leaves. This work provides valuable new insights into the matching of the structure of powdery mildew-covered plant leaves with the properties of surfactant solutions. © 2021 Society of Chemical Industry.

The biologically synthesised tellurium nanoparticles (Te NPs) were applied in the fabrication of Te NP‐embedded polycaprolactone/gelatin (PCL/GEL) electrospun nanofibres and their antioxidant and in vivo wound healing properties were determined. The as‐synthesised nanofibres were characterised using scanning electron microscopy (SEM), energy‐dispersive X‐ray (EDX) spectroscopy and elemental mapping, thermogravimetric analysis (TGA), and Fourier‐transform infrared (FTIR) spectroscopy. The mechanical properties and surface hydrophobicity of scaffolds were investigated using tensile analysis and contact angle tests, respectively. The biocompatibility of the produced scaffolds on mouse embryonic fibroblast cells (3T3) was evaluated using MTT assay. The highest wound healing activity (score 15/19) was achieved for scaffolds containing Te NPs. The wounds treated with PCL/GEL/Te NPs had inflammation state equal to the positive control. Also, the mentioned scaffold represented positive effects on collagen formation and collagen fibre's horizontalisation in a dose‐dependent manner. The antioxidative potency of Te NP‐containing scaffolds was demonstrated with lower levels of malondialdehyde (MDA) and catalase (∼3 times) and a higher level of glutathione (GSH) (∼2 times) in PCL/GEL/Te NP‐treated samples than the negative control. The obtained results strongly demonstrated the healing activity of the produced nanofibres, and it can be inferred that scaffolds containing Te NPs are suitable for wound dressing.

The impact of heat treatment and wetting–drying cycles on the wetting properties of sandy forest soils was explored. Topsoil and upper subsoil were sampled at three beech forest sites in northern Germany. The air-dried soils were treated at 20, 40 and 80°C for 24 h, with materials treated at 20°C serving as reference. After wetting, materials were air-dried or shock-frozen in liquid N2 and freeze-dried. Interfacial properties were monitored by sessile drop contact angles (CAs) and X-ray photoelectron spectroscopy (XPS), which provide physical and chemical information on the outermost particle interface layer. CAs of reference samples were around 90° and significantly increased after 80°C-treatment to >90°, whereas 40°C-treatment had in comparison to reference soils no distinct impact on CA. Depending on the initial temperature treatment, air-drying after wetting decreased CA to 60–80% and shock-freezing and freeze-drying decreased CA to 10–50% of the reference value. Results suggest that shock-freezing may preserve the organic matter molecular structure that prevails during contact with water at the solid–liquid interface, thus indicating the wettability of the wet surface. Generally, wetting–drying cycles had the least impact on 80°C-treated material. XPS analysis confirmed dynamic interfacial molecular restructuring processes by changes in O and C content and the content of non-polar C compounds. A second heat treatment after two wetting–drying cycles again proved the distinct and pronounced impact of 80°C-treatment on CA, especially with prior shock-freezing and freeze-drying. In conclusion, the findings of our study indicate a sensitive and partly reversible reorganization of the solid interfacial wetting properties. Results may conceptually be used to develop dynamic wettability models, which are needed to simulate the sensitive interplay between wettability and dynamic soil hydraulic functions at sites that are exposed to intensive and periodic moisture fluctuations. Highlights: T > 40°C increased contact angle; after wetting contact angle depended on how the water was removed Shock-freezing and freeze-drying preserves contact angle of the wetted state Contact angle changes confirm interface molecular restructuring due to heat treatment or wetting Contact angle change goes along with changes in element content within XPS analysis depth.

Hydroxyapatite (HAp) nanoparticles stabilized Pickering emulsions were prepared by dichloromethane (CH2 Cl2 ) dissolved poly(L-lactic acid) (PLLA) as the oil phase and the deionized water with different concentrations of cetyltrimethyl-ammonium bromide (CTAB) as the aqueous phase. Effect of CTAB concentration on emulsions type and stability were studied. The emulsion type underwent a two-phase inversion, and emulsion stability increased first and then decreased with increasing CTAB concentrations. Besides, effect of CTAB concentration on zeta potential, aggregate size, contact angle of HAp nanoparticles and the oil-water interfacial tension were studied. The results indicated that zeta potential value of HAp nanoparticles changed from negative to positive, and the contact angle increased to over 80° initially and then decreased to below 40° rapidly. The distribution of HAp nanoparticles on the surface of emulsion droplets with different concentrations of CTAB (5 and 20 mM) was characterized using laser-induced confocal microscope. It revealed the distribution of HAp nanoparticles changed with different CTAB concentrations. The cured PLLA materials were obtained after the solvent being volatilized using as-received emulsions as templates. Scanning electron microscope images showed both microspheres and porous materials with interconnected pore structure were obtained. In conclusion, the microstructure of microspheres or porous PLLA materials is controllable by adjusting the property of HAp nanoparticles stabilized Pickering emulsions with appropriate amount of CTAB.

A simple method for the preparation of multifunctional nanocomposite was developed towards the production of water-repellent, electrically conductive, and photoluminescent film onto cotton fibres. The nanocomposite was composed of lanthanide-doped strontium aluminium oxide and silicon rubber dispersed in petroleum ether. The electrically conductive fabric was woven from nickel strips twisted with cotton filaments as core yarns, which were wrapped with pure cotton yarns. The nanoparticles (NPs) of lanthanide-doped strontium aluminium oxide were mixed with environmentally friendly room-temperature vulcanizing silicon rubber (RTV-SR) dissolved in petroleum ether to give the silicon rubber/strontium aluminate nanocomposites. The produced nanocomposites were applied onto electrically conductive cotton/nickel fibres using spray-coating technology. The surface of the cotton/nickel fibres showed different hierarchical morphologies depending on the total content of the silicon rubber. Additionally, the superhydrophobic effect was found to be improved upon increasing the total content of the luminescence pigment NPs. The morphologies of the prepared phosphor NPs were determined using transmission electron microscopy (TEM). The generated transparent luminescence film demonstrated an absorbance peak at 358 nm and an emission peak at 515 nm. Photoluminescence of cotton fibres was monitored with the generation of different colours, including grey, green-yellow, bright white, and turquoise shades as recognized using CIE Laboratory colorimetric parameters. The emission, excitation, lifetime, and decay time spectra of the phosphorescent spray-coated cotton samples were studied. The surface morphologies and chemical compositions of the spray-coated cotton/nickel were investigated using wavelength-dispersive X-ray fluorescence (WD-XRF), scanning electron microscope (SEM), Fourier-transform infrared spectra (FTIR), and energy-dispersive X-ray analyzer (EDAX). The superhydrophobic effects were characterized by measuring static water contact angle. The comfort characteristics of the treated cotton/nickel substrates were assessed by investigating their air permeability and stiffness. The treated cotton/nickel fabrics also displayed an antimicrobial activity. The results displayed water repellence with high electrical conductivity and photoluminescence properties.

This work is aimed to investigate the permeation characteristic of CA/γ‐CD‐metal organic framework (MOF) based mixed matrix membranes (MMM) for CO2/CH4 separation. The defect‐free CA/γ‐CD‐MOF MMMs with dense, isotropic morphology were fabricated using solution casting method. The fabricated membranes were characterized through Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), ultimate tensile testing, and contact angle measurements. The characterization techniques revealed the uniform dispersion of filler in cellulose acetate matrix and absence of the agglomerates or cracks in the synthesized membrane samples. Moreover, the CO2/CH4 separation performance of fabricated membrane was evaluated using single and mixed gas permeation tests. A general trend of decreasing permeability and selectivity, that is, 36.79–35 of both CO2 and CH4 was observed by increasing the filler weight percentage (0.2–1.0) and pressure (1–5 bar). However, the highest CO2/CH4 selectivity of 38.49 was achieved by CA/γ‐CD‐MOF 0.4wt% MMM. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.

Nowadays, the problem of oil spill and organic solvent pollution has become more and more serious, and developing a green and efficient treatment method has become a research hotspot. Herein, the preparation of porous super‐hydrophobic aerogel by directional freezing with cellulose nanofibre (CNF) as the base material, polyvinyl alcohol (PVA) as the cross‐linking agent and montmorillonite (MMT) as the modifier and filler, followed by hydrophobic treatment with chemical vapour deposition is reported. The prepared composite aerogel presented three‐dimensional inter‐perforation network structure, low density (26.52 mg⋅cm−3), high porosity (96.1 %) and good hydrophobicity (water contact angle of 140°). Notably, the composite aerogel has a good adsorption effect on different oils and organic solutions, and its adsorption capacity can reach 40–68 times of its initial weight. After complete adsorption, the aerogel could be easily collected. More importantly, the composite aerogel had high strength, whose compressive stress at 70 % strain reached 0.15 MPa and could bear over 1290 times its weight without deformation after 2 weeks. A new, green, simple and efficient absorbent for the adsorption of oils and organic solvents is provided.

Background Chitin nanocrystals (ChN) are insoluble particles that can be used as stabilizers for Pickering emulsions. Their unique cationic properties and antibacterial activity have generated considerable interest among researchers. However, ChN have remained largely underexplored. Furthermore, the droplets of the emulsions stabilized by ChN are as large as 10-100 μm, and their physical stability requires further improvement. Some studies have shown that the spontaneous reaction of oppositely charged particles can effectively stabilize the emulsions. Positively charged ChN and negatively charged fucoidan (F) were therefore compounded to stabilize Pickering emulsions, and the stability of these emulsions was analyzed qualitatively. Results The results showed that the composite particles comprising two polysaccharides in a mass ratio of 1:1 and at a pH of 2 (ChN1 -F1 -pH 2) possessed the lowest sulfate content (20.1%) and almost zero potential (-3 mV), indicating a high degree of neutralization of the positively charged amino group in ChN and the negatively charged sulfate group in F. Meanwhile, ChN1 -F1 -pH 2 displayed a dense network structure that improved the dispersibility and wettability (contact angle = 9.3°). Fourier transform infrared spectroscopy results confirmed that ChN and F were effectively combined through electrostatic interaction or neutralization to produce a polyelectrolyte complex. Furthermore, the particle size of the Pickering emulsion stabilized by ChN-F was significantly reduced, and the maximum size did not exceed 10 μm; the physical and storage stability also improved. The ChN1 -F1 -pH 2 emulsion presented excellent storage stability; in particular, the emulsions stabilized by ChN1 -F1 -pH 5 and ChN1 -F1 -pH 6 exhibited excellent flocculation stabilities. Conclusion The size of the emulsion droplets stabilized by the oppositely charged polysaccharide particles (ChN-F complexes) reduced significantly. Furthermore, by changing the mass ratio and pH, the microstructure and binding degree of the complexes can be adjusted, thereby promoting their adsorption on the oil-water interface and improving the stability of the Pickering emulsion. © 2020 Society of Chemical Industry.

This study reports the differences in the protein composition of salivary pellicles formed under in situ conditions on two Titanium (Ti) surfaces, with different roughness and wettability. Smooth pretreatment Ti surfaces (Ti-PT) with an average roughness (Ra) of 0.45 μm and a water contact angle (WCA) of 92.4°, as well as a more rough sandblasted, large grit, acid-etched treatment Ti surfaces (Ti-SLA) with a Ra of 3.3 μm and WCA of 131.8°, were tested. The salivary pellicles were quantitatively analyzed by bicinchoninic acid assays, and the protein identification was performed by Nano-LC-MS/MS (nano mass spectrometry). Protein levels of 2.5, and 9.1 μg/ml were quantified from the detached salivary pellicle formed on the Ti-PT and Ti-SLA surfaces, respectively. Using Nano-LC-MS/MS, a total of 597 proteins were identified on all the substrates tested; 43 proteins were identified only on the Ti-PT, and 226 proteins were adsorbed solely on the Ti-SLA substrates. The physicochemical characteristics of the Ti implant surfaces modified the amount and the identity of the salivary proteome of the pellicles formed, confirming the high selectivity of the protein pellicle formed on a surface once is exposed in the oral cavity.