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1.
Chemosphere ; 286(Pt 1): 131520, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34298294

RESUMO

The remediation of oil spills and treatment of oily wastewater remains challenging to cope with nowadays. This has caused a surge in demand on adsorbent materials with multi-functionalities to effectively separate oils and nonpolar solvents from water. A superhydrophobic composite aerogel prepared from industrial waste-derived leached carbon black waste (LCBW) and polyvinyl alcohol (PVA) was developed in this work via conventional freeze-casting followed by surface coating. The composite aerogel was ultralight and porous with porosity >85% and tunable density ranging between 0.015 and 0.065 g/cm3. It was found that the embedded LCBW in the PVA network is crucial to impart superhydrophobicity and superoleophilicity to the aerogel as it enhances the surface roughness. Wettability test showed that composite aerogel prepared from 0.5 wt% PVA at PVA/LCBW ratio of 1 exhibited the highest water contact angle (156.7 ± 2.9°). LCBW also improved the thermal stability of the composite aerogel. With its superior selectivity, PVA/LCBW aerogel was used as selective adsorbent for a variety of oils and organic solvents. The adsorption test showed that the composite aerogel exhibited an adsorption capacity up to 35 times its original weight and could be reused repeatedly and easily recovered through a simple drying method.


Assuntos
Álcool de Polivinil , Água , Géis , Óleos , Óleos Vegetais , Fuligem , Molhabilidade
2.
J Colloid Interface Sci ; 606(Pt 2): 1077-1086, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34487930

RESUMO

HYPOTHESIS: Droplet wetting on a solid substrate is affected by the surface heterogeneity. Introducing patterned wettability on the solid substrate is expected to engender anisotropic wetting morphologies, thereby manipulating droplet wetting behaviors. However, when the droplet size is comparable with that of the surface heterogeneity, the wetting morphologies cannot be depicted by the quintessential Cassie's theory but should be possible to be predicted from the perspective of thermodynamics via surface energy minimization. METHODS: Here, we investigate the equilibrium droplet shapes on chemically patterned substrates by using an analytical model, phase-field simulations, and experiments. The former two methods are sharp and diffuse interface treatments, respectively, which both are based on minimizing the free energy of the system. The experimental results are obtained by depositing droplets on chemically patterned glass substrates. FINDINGS: Various anisotropic wetting shapes are found from the three methods. Excellent agreement is observed between different methods, showing the possibility to quantify the anisotropic wetting droplet morphologies on patterned substrates by present methods. We also address a series of non-rotationally symmetric droplet shapes, which is the first resport about these special wetting morphologies. Furthermore, we reveal the anisotropic wetting shapes in a quasi-equilibrium evaporation process.


Assuntos
Propriedades de Superfície , Anisotropia , Simulação por Computador , Molhabilidade
3.
J Colloid Interface Sci ; 606(Pt 2): 1563-1571, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34500159

RESUMO

Endowing nanofibrous membranes with special wettability has always been the dominant strategy to improve the separation performance for water-in-oil emulsions. In this work, a rational design of deacetylated cellulose acetate/polyvinylidene fluoride (dCA/PVDF) Janus nanofibrous membrane, with asymmetric wettability in either air, water or diesel environment, was developed via sequential electrospinning PVDF and CA membranes followed by alkali treatment. In the process of water-in-diesel emulsion separation, the under-diesel superhydrophilic dCA layer is able to capture the emulsified water and strengthens the demulsification ability of the Janus membrane, while the under-diesel superhydrophobic PVDF layer acts as a water barrier and further improves the separation ability. The Janus membrane therefore exhibited prominent separation performance not only for the water/diesel mixture (separation efficiency 99.98%) but also for the surfactant-stabilized water-in-diesel emulsion with l vol% water (separation efficiency 97.74%). Moreover, the Janus membrane maintained high separation efficiency over 96% after repeated use for 50 times or soaking in corrosive solutions for 24 h. The Janus dCA/PVDF nanofibrous membrane possesses competitive efficiency, reusability and acid/alkali resistance, making it a promising candidate as the separation membrane for the surfactant-stabilized water-in-diesel emulsion.


Assuntos
Nanofibras , Água , Emulsões , Membranas Artificiais , Molhabilidade
4.
J Colloid Interface Sci ; 606(Pt 1): 57-66, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34388573

RESUMO

HYPOTHESIS: Weakly bound, physisorbed hydrocarbons could in principle provide a similar water-repellency as obtained by chemisorption of strongly bound hydrophobic molecules at surfaces. EXPERIMENTS: Here we present experiments and computer simulations on the wetting behaviour of water on molecularly thin, self-assembled alkane carpets of dotriacontane (n-C32H66 or C32) physisorbed on the hydrophilic native oxide layer of silicon surfaces during dip-coating from a binary alkane solution. By changing the dip-coating velocity we control the initial C32 surface coverage and achieve distinct film morphologies, encompassing homogeneous coatings with self-organised nanopatterns that range from dendritic nano-islands to stripes. FINDINGS: These patterns exhibit a good water wettability even though the carpets are initially prepared with a high coverage of hydrophobic alkane molecules. Using in-liquid atomic force microscopy, along with molecular dynamics simulations, we trace this to a rearrangement of the alkane layers upon contact with water. This restructuring is correlated to the morphology of the C32 coatings, i.e. their fractal dimension. Water molecules displace to a large extent the first adsorbed alkane monolayer and thereby reduce the hydrophobic C32 surface coverage. Thus, our experiments evidence that water molecules can very effectively hydrophilize initially hydrophobic surfaces that consist of weakly bound hydrocarbon carpets.


Assuntos
Silício , Água , Interações Hidrofóbicas e Hidrofílicas , Propriedades de Superfície , Molhabilidade
5.
J Colloid Interface Sci ; 606(Pt 1): 236-247, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34390991

RESUMO

HYPOTHESIS: In this original work, we aim to control both the surface wetting and fluorescence properties of extremely ordered and porous conducting polymer nanotubes prepared by soft template electropolymerization and post-grafting. For reaching this aim, various substituents of different hydrophobicity and fluorescence were post-grafted and the post-grafting yields were evaluated by surface analyses. We show that the used polymer is already fluorescent before post-grafting while the post-grafting yield and as a consequence the surface hydrophobicity highly depend on the substituent. EXPERIMENTS: Here, we have chosen to chemically grafting various fluorinated and aromatic substituents using a post-grafting in order to keep the same surface topography. Flat conducting polymer surfaces with similar properties have been also prepared for determining the surface energy with the Owens-Wendt equation and estimating the post-grafting yield by X-ray Photoemission Spectroscopy (XPS) and Time of Flight Secondary Emission Spectrometry (ToF-SIMS). For example, using fluorinated chains of various length (C4F9, C6F13 and C8F17), it is demonstrated that the surface hydrophobicity and oleophobicity do not increase with the fluorinated chain length due to the different post-grafting yields and because of the presence of nanoroughness after post-grafting. FINDINGS: These surfaces have high apparent water contact angle up to 130.5° but also strong water adhesion, comparable to rose petal effect even if there are no nanotubes on petal surface. XPS and ToF-SIMS analyses provided a detailed characterisation of the surface chemistry with a qualitative classification of the grafted surfaces (F6 > F4 > F8). SEM analysis shows that grafting does not alter the surface morphology. Finally, fluorescence analyses show that the polymer surfaces before post-treatment are already nicely fluorescent. Although the main goal of this paper was and is to understand the role of surface chemistry in tailoring the wetting properties of these surfaces rather than provide specific application examples, we believe that the obtained results can help the development of specific nanostructured materials for potential applications in liquid transport, or in stimuli responsive antimicrobial surfaces.


Assuntos
Nanotubos , Água , Polímeros , Propriedades de Superfície , Molhabilidade
6.
Sci Total Environ ; 803: 150010, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34487897

RESUMO

This study investigates the impact of aerosol liquid water content (ALWC) and related factors, i.e., relative humidity (RH), aerosol mass concentration (PM2.5), and aerosol hygroscopicity, on aerosol optical properties, based on field measurements made in the Pearl River Delta (PRD) region of China at the surface (1 November 2019 to 21 January 2020) and in the upper boundary layer (the 532-m Guangzhou tower from 1 February to 21 March 2020). In general, temporal variations in the ambient aerosol backscattering coefficient (ßp) and ALWC followed each other. However, the surface ßp and 532-m ßp had generally opposite diurnal variation patterns, caused by dramatic differences in PM2.5 and ambient RH between the surface and the upper boundary layer. The ambient 532-m RH was systematically higher than the surface RH, with the latter having a much pronounced diurnal cycle than the former. The surface PM2.5 concentration was systematically higher than the PM2.5 concentration at 532 m, and their diurnal cycle patterns were overall opposite. These dramatic differences reveal that the atmospheric variables, i.e., ambient RH and the PM2.5 concentration in the upper boundary layer, cannot be directly represented by the same variables at the surface. Vertical variability should be considered. Clear differences in the sensitivities of aerosol light scattering to ambient RH, PM2.5, and aerosol hygroscopicity between the two levels were found and examined. Aerosol chemical composition played a minor role in causing the differences between the two levels. In particular, ßp was more sensitive to PM2.5 at the surface level but more to the ambient RH in the upper boundary layer. The larger contribution of aerosol loading to the variability in ßp at the surface implies that local emission controls can decrease ßp and further improve atmospheric visibility effectively at the surface during winter in the PRD region.


Assuntos
Poluentes Atmosféricos , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental , Umidade , Material Particulado/análise , Molhabilidade
7.
J Colloid Interface Sci ; 607(Pt 1): 514-529, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34509122

RESUMO

HYPOTHESIS: 'Bridge splitting' is considered in the case of capillary adhesion: a fixed total volume of liquid is split into multiple capillary bridges. Previous studies have shown that bridge splitting only enhances the capillary-induced adhesion force between two planar surfaces in specific circumstances. We hypothesise that bridge splitting significantly enhances the total adhesion force between rough surfaces, since mobile wetting bridges can naturally migrate to narrower gaps. This migration of capillary bridges should also provide a resistance to shear. NUMERICAL EXPERIMENTS: We theoretically consider an idealized system of many liquid bridges confined between two solid surfaces. By numerically calculating the shape of a single bridge, the total adhesion force is found as the number of bridges and roughness are varied. The resistance to shear is also calculated in the limit of strong surface tension or small shears. FINDINGS: Bridge splitting on a rough surface significantly enhances the adhesion force, with an enhancement that increases with the amplitude of the roughness; maximising over the number of bridges can increase the total adhesion force by an order of magnitude. Resistance to shear is shown to increase linearly with the translation velocity, and the behaviour of many such shearing bridges is quantified.


Assuntos
Molhabilidade , Fenômenos Físicos , Tensão Superficial
8.
J Colloid Interface Sci ; 607(Pt 2): 1699-1708, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34592555

RESUMO

HYPOTHESIS: Quartz is one of the most common but important minerals, and its wettability plays a significant role in affecting various natural and industrial processes. Studies have revealed that different crystal faces of quartz are with different wettabilities, but its mechanism is still vague. EXPERIMENTS AND SIMULATIONS: For specifying the mechanism of crystal face dependent wettability, the contact angles of three different liquids on the crystal faces of α-quartz are measured; the time-of-flight secondary ion mass spectrometry (ToF-SIMS) is employed to establish the crystal surface models; molecular dynamics (MD) simulations with the surface models are performed to understand the wetting behavior at molecular scale. FINDINGS: Based on the contact angle measurements, the wettabilities of different crystal faces of α-quartz are found different, which can be directly attributed to the concentration of hydroxyl group on crystal faces based on ToF-SIMS results. MD simulations yield consistent results with the contact angle order recognized from experiments, revealing that the surface hydroxyl group controls the wettability of α-quartz crystal faces. It is also recognized that the pristine surface atomic arrangement, especially the surface concentration of unsaturated bond (an intrinsic property of α-quartz), is the intrinsic cause of the difference in the concentration of hydroxyl group of the crystal surface.


Assuntos
Quartzo , Espectrometria de Massa de Íon Secundário , Simulação de Dinâmica Molecular , Molhabilidade
9.
J Colloid Interface Sci ; 607(Pt 2): 1741-1753, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34598031

RESUMO

HYPOTHESIS: A unique adhesion-shielding (AS)-based method could be used to manufacture magnetic Janus nanoparticles (IM-JNPs) of promising interfacial activities, asymmetric surface wettability, and great performance on deoiling from oily wastewater under the external magnetic field. EXPERIMENTS: The IM-JNPs were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). The interfacial properties of IM-JNPs were investigated by the measurements of interfacial pressure-area isotherms (π-A), oil-water interfacial tension, and the related crumpling ratio. The Langmuir-Blodgett (L-B) technique was used to determine the asymmetric surface wettability of the IM-JNPs. The performance and recyclability of IM-JNPs for treating oily wastewater were also investigated. FINDINGS: Using the proposed AS-based method, 17.9 g IM-JNPs were synthesized at a time and exhibited excellent interfacial properties, as indicated by decreasing oil-water interfacial tension from 38 to 27 mN/m. The crumpling behavior of the oil droplet further demonstrated the irreversible deposition of IM-JNPs at the oil droplet surfaces. The L-B technique and water contact angle measurement confirmed the asymmetric surface wettability of the IM-JNPs. The IM-JNPs were applied to successful removal of > 90% emulsified oil droplets from the household-produced oily wastewater under the external magnetic field while realizing facile recyclability and regeneration.


Assuntos
Nanopartículas Multifuncionais , Fenômenos Magnéticos , Óleos , Tensão Superficial , Molhabilidade
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120256, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34416540

RESUMO

As an important component of atmospheric aerosols, water is profoundly related with aerosol hygroscopicity and provides a medium for atmospheric heterogeneous reactions. The quantitative analysis of water content in aerosol droplets is instrumental to understanding atmospheric chemistry, as well as to addressing the related environmental issues, such as air pollution and climate change. Fourier transform infrared (FTIR) spectroscopy has been widely adopted to quantify the amount of water content in atmospheric aerosols, which is based on the absorbance of OH functional group in proportion to water content. However, in the OH stretching vibration band around 3400 cm-1, spectral distortions may occur, making a quantitative analysis impossible. In addressing this issue, here we put forth a model to simulate the FTIR absorption of hemispherical water droplets, along with a quantitative description of the spectral distortion. Our model prediction was benchmarked with the microscopic-FTIR experiments conducted on sodium sulfate droplets, and good agreements between theoretical and experimental results were found. We observed that the absorbance spanning across the mid-wavenumber infrared region increases with water absorption coefficients; while such an increasing trend was not seen in the 3400 cm-1 band. We speculate that the spectral saturated absorption is related to the absorption coefficient of water and the ratio of the projected area of droplets to the aperture area. In addition, the effects of droplet size and number density on the absorption spectra were investigated. The waveband range of the saturated absorption broadens with an increase in droplet radius. On the other hand, as the number density of water droplets increases, the absorption at 3400 cm-1 is enhanced, and the characteristic peak of condensed water becomes increasingly sharper, asymptotic to the typical infrared spectra of water collected by the pressing method.


Assuntos
Água , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Molhabilidade
11.
J Colloid Interface Sci ; 605: 163-172, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34311311

RESUMO

HYPOTHESIS: In terms of the Young's equation, the temperature dependence of liquid-solid contact angle is affected by the surface material, so the wetting behavior could be tuned by both changing the temperature and surface material. However, the synergistic effects of surface material and temperature on the water contact angle remain unclear, especially at elevated temperatures. EXPERIMENTS: In this study, a systematic characterization of water contact angle against various smooth metallic and nonmetallic surfaces was conducted for temperatures up to 300 ℃ in a high-pressure chamber at 15 MPa. The measured results were finally compared with the predictions made by the sharp-kink approximation model. FINDINGS: Not surprisingly, it was observed the temperature-dependent water contact angle is sensitive to the type of solid surface. The temperature coefficients and critical temperature points on the contact-angle-temperature curves can be manipulated by altering the surface material. However, the influence of surface material is weakened by raising temperature, thus leading to the nearly consistent temperature-dependent water contact angle over 120℃. Additionally, the necessity of investigating the internal flows within the water drops was highlighted to unravel the positive temperature correlation of the water contact angle at high temperatures, in view of the presence of non-spherical-cap-shaped drops.


Assuntos
Água , Temperatura , Molhabilidade
12.
Braz. j. oral sci ; 20: e211194, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1253930

RESUMO

Aim: The aim of this study was to evaluate the effect of ethanol-conditioned dentin on endodontic sealer penetration into dentinal tubules by confocal laser scanning microscopy (CLSM). Methods: Forty human maxillary anterior teeth were instrumented and divided into four groups (n = 10) according to the drying methods: 1) wet: vacuum only, 2) paper points: vacuum + absorbent paper points, (3) 70% ethanol: 70% ethanol (1 min) + vacuum + absorbent paper points, and (4) 100% ethanol: 100% ethanol (1 min) + vacuum + absorbent paper points. All root canals were filled with resin-based endodontic sealer. Four sections from each third (cervical, middle, and apical) were examined by CLSM. Root canal wall perimeter infiltrated by sealer, maximum depth of sealer penetration, percentage of penetrated area, and fluorescence intensity of rhodamine B were measured. Statistical analysis was performed by analysis of variance and Tukey's tests (α = 0.05). Results: No statistical difference was found when percentage of root canal wall coverage infiltrated by sealer were compared. The groups in which ethanol solutions were used presented greater depth of sealer penetration, higher percentage of penetrated area, and higher fluorescence intensity of rhodamine B (p< 0.05) when compared with the wet and paper point groups. Overall, 100% ethanol produced better results than 70% ethanol, except for rhodamine B intensity (cervical third). In addition, the absorbent paper points drying method behaved better than did vacuum only group, except for rhodamine B intensity (apical third). Conclusion: Ethanol-conditioned dentin improved the penetration of resin-based sealer into dentinal tubules, especially at the concentration of 100%


Assuntos
Humanos , Molhabilidade , Microscopia Confocal , Cimentos de Resina , Dentina , Etanol , Endodontia
13.
Planta ; 255(1): 1, 2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34837118

RESUMO

MAIN CONCLUSION: Time-dependent contact angle measurements of pure water on barley leaf surfaces allow quantifying the kinetics of surfactant diffusion into the leaf. Barley leaf surfaces were sprayed with three different aqueous concentrations (0.1, 1.0 and 10%) of a monodisperse (tetraethylene glycol monododecyl ether) and a polydisperse alcohol ethoxylate (BrijL4). After 10 min, the surfactant solutions on the leaf surfaces were dry leading to surfactant coverages of 1, 10 and 63 µg cm-2, respectively. The highest surfactant coverage (63 µg cm-2) affected leaf physiology (photosynthesis and water loss) rapidly and irreversibly and leaves were dying within 2-6 h. These effects on leaf physiology did not occur with the lower surfactant coverages (1 and 10 µg cm-2). Directly after spraying of 0.1 and 1.0% surfactant solution and complete drying (10 min), leaf surfaces were fully wettable for pure water and contact angles were 0°. Within 60 min (0.1% surfactant) and 6 h (1.0% surfactant), leaf surfaces were non-wettable again and contact angles of pure water were identical to control leaves. Scanning electron microscopy investigations directly performed after surfactant spraying and drying indicated that leaf surface wax crystallites were partially or fully covered by surfactants. Wax platelets with unaltered microstructure were fully visible again within 2 to 6 h after treatment with 0.1% surfactant solutions. Gas chromatographic analysis showed that surfactant amounts on leaf surfaces continuously disappeared over time. Our results indicate that surfactants, applied at realistic coverages between 1 and 10 µg cm-2 to barley leaf surfaces, leading to total wetting (contact angles of 0°) of leaf surfaces, are rapidly taken up by the leaves. As a consequence, leaf surface non-wettability is fully reappearing. An irreversible damage of the leaf surface fine structure leading to enhanced wetting and increased foliar transpiration seems highly unlikely at low surfactant coverages of 1 µg cm-2.


Assuntos
Hordeum , Tensoativos , Folhas de Planta , Água , Molhabilidade
14.
Sensors (Basel) ; 21(19)2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34640953

RESUMO

Flexible capacitive humidity sensors are promising for low-cost, wearable, and radio frequency identification sensors, but their nonlinear response is an important issue for practical applications. Herein, the linearity of humidity response was controlled by surface water wettability and operating frequency of sensor, and the mechanism was explained in detail by surface water condensation. For a sensor with a Ag interdigitated electrode (IDE) on a poly(ethylene terephthalate) substrate, the capacitance showed a small linear increase with humidity up to 70% RH but a large nonlinear increase in the higher range. The response linearity was increased by a hydrophobic surface treatment of self-assembled monolayer coating while it was decreased by an ultraviolet/ozone irradiation for hydrophilicity. It was also increased by increasing the frequency in the range of 1-100 kHz, more prominently on a more hydrophilic surface. Based on experiment and simulation, the increase in sensor capacitance was greatly dependent on the geometric pattern (e.g., size, number, and contact angle) and electrical permittivity of surface water droplets. A larger and more nonlinear humidity response resulted from a larger increase in the number of droplets with a smaller contact angle on a sensor surface with higher water wettability and also from a higher permittivity of water at a lower frequency.


Assuntos
Água , Eletrodos , Umidade , Interações Hidrofóbicas e Hidrofílicas , Molhabilidade
15.
Analyst ; 146(22): 6815-6821, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34643194

RESUMO

Solid-state nanochannels have attracted considerable attention for their similar ion transport properties to biological ion channels. The construction of porous ion channels with good stability at the submicro/micrometer scale is very beneficial to develop large-area ion channel devices. In this manuscript, based on in-situ thermal crosslinking of a small organic molecule containing triphenylamine and styrene groups, we construct a heterogeneous membrane with asymmetrical charge and wettability on cylindrical anodic aluminum oxide (AAO) channels (D ≈ 319 nm). This heterogeneous membrane has typical ion current rectification characteristics with a high rectification ratio of 36.9 and good stability. This work provides an effective strategy for the construction of submicrochannel heterogeneous membranes and also broadens the application range of bionic ion channels.


Assuntos
Força Próton-Motriz , Transporte de Íons , Porosidade , Molhabilidade
16.
ACS Biomater Sci Eng ; 7(11): 5039-5047, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34637254

RESUMO

The peri-implant soft tissue with inferior adhesion takes a long healing period to form, which is undesirable for the reaction around the peri-implant soft tissues. The aim of this study is to improve the physicochemical properties of titanium (Ti) and zirconia (ZrO2) implant abutments and shorten the formation period of periabutment epithelium tissue. A nonthermal atmospheric plasma brush (NTAPB, N) was employed for Ti and ZrO2 activation. The surface topographies, roughness, crystallinity, wettability, and chemical elements of the abutment materials were examined. The epithelial cell behavior analysis and tissue remodeling of the periabutment epithelial tissue were performed in vitro and in vivo. N-Ti and N-ZrO2 had a similar good surface wettability, with a 65 and 70% increase in oxygen content and a 70 and 75% decrease in carbon content, respectively. Both N-Ti and N-ZrO2 showed excellent adhesion, spread, and proliferation of epithelial cells in vitro, with improved adhesion molecule expression levels compared to untreated samples. N-Ti and N-ZrO2 abutments were placed in the implantation sites of rats. From week 2 to week 6 after implantation, N-Ti and N-ZrO2 had similar periabutment epithelium tissue formation, and both had increased plectin-positive and laminin γ2-positive cell numbers compared to Ti and ZrO2. The NTAPB shows promising abutment modification abilities. It promotes the expression levels of adhesion molecules and the epithelial cell performance, which later leads to a quicker formation and remodeling of the important periabutment epithelial tissue.


Assuntos
Titânio , Zircônio , Animais , Epitélio , Ratos , Molhabilidade
17.
Water Res ; 206: 117759, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34715525

RESUMO

Freshwater shortage has been a terrible threat for the sustainable progress and development of human society in 21st century. Inspired from natural creatures, harvesting water from atmosphere has been a feasible and effective method to alleviate water shortage crisis. However, the recent works related to water collection just focuses on how to optimize fog-harvesting manners and efficiencies, the safety and availability of collected water are always ignored. In this paper, we proposed a new strategy accessed to freshwater resources through combining water collection and purification together on eco-friendly superwettable material inspired by cactus spines and desert beetles. Six superhydrophilic wedge-shaped patterns prepared by P25 TiO2 nanoparticles (NPs) were constructed on candle soot@polydimethylsiloxane (CS@PDMS) superhydrophobic coating. The special superhydrophilic regions not only effectively captured water from foggy environment but generated Laplace pressure gradient to faster drive water away. The bioinspired material exhibited an efficient water collection rate (WCR) of 14.9 ± 0.2 mg min-1 cm-2, which was 5.3 and 2.5 times larger than that on uniformed superhydrophilic and superhydrophobic surfaces, respectively. Because of the existence of photocatalytic P25 NPs in wetting areas, the harvested wastewater containing nine kinds of pesticides (0.5 mg/L) could be purified in low concentrations (< 5%) under UV light (365 nm, 5.0 ± 0.6 mW cm-2). Ten zebrafishes were still alive in such purified water for 72 h, as a contrast, the same number of fishes would almost die in untreated harvested wastewater in just 7 h. This work indeed opens up a new sight to freshwater accessibility, aiming to a promising project for alleviating water shortage around the world.


Assuntos
Cactaceae , Besouros , Animais , Humanos , Água , Tempo (Meteorologia) , Molhabilidade
18.
J R Soc Interface ; 18(183): 20210488, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34637642

RESUMO

Complex and at times extreme environments have pushed many bird species to develop unique eggshell surface properties to protect the embryo from external threats. Because microbes are usually transmitted into eggs by moisture, some species have evolved hydrophobic shell surfaces that resist water absorption, while also regulating heat loss and the exchange of gases. Here, we investigate the relationship between the wettability of eggshells from 441 bird species and their life-history traits. We measured the initial contact angle between sessile water droplets and the shell surface, and how far the droplet spread. Using phylogenetic comparative methods, we show that body mass, annual temperature and eggshell maculation primarily explained variance in water contact angle across eggshells. Species nesting in warm climates were more likely to exhibit highly hydrophobic eggshells than those nesting in cold climates, potentially to reduce microbial colonization. In non-passerines, immaculate eggs were found to have more hydrophobic surfaces than maculate eggshells. Droplets spread more quickly on eggshells incubated in open nests compared to domed nests, likely to decrease heat transfer from the egg. Here, we identify clear adaptations of eggshell wettability across a diverse range of nesting environments, driven by the need to retain heat and prevent microbial adhesion.


Assuntos
Aves , Casca de Ovo , Animais , Filogenia , Água , Molhabilidade
19.
An Acad Bras Cienc ; 93(4): e20190534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34705930

RESUMO

The understanding of the mechanisms that affect oil production in carbonaceous reservoirs has become increasingly necessary, particularly in limestone, which mostly features oil wettability properties that diminishes petroleum recovery. The objective of this work was to investigate the ability of anionic surfactant (coconut oil derived soap) to adsorb in limestone in order to promote wettability change. The finite-bath technique was employed with changes in temperature, mass of adsorbent material (limestone), contact time and surfactant concentration. Contact angle and zeta potential measurements were also made. The surfactant could be significantly adsorbed on the rock, possibly due to ions that are charged oppositely to the species on the rock surface. A temperature rise from 30 °C to 50 °C was unfavourable to the adsorption capacity. The oil-wettable in-natura limestone had its wettability reduced after the treatment with surfactant. The zeta potential measurements showed that electrostatic attractions play an important role in the adsorption process.


Assuntos
Carbonato de Cálcio , Tensoativos , Adsorção , Propriedades de Superfície , Molhabilidade
20.
Environ Sci Technol ; 55(20): 14156-14164, 2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34597031

RESUMO

Although membrane distillation (MD) has been identified as a promising technology to treat hypersaline wastewaters, its practical applications face two prominent challenges: membrane wetting and fouling. Herein, we report a facile and scalable approach for fabricating a Janus MD membrane comprising a dense polyvinyl alcohol (PVA) surface layer and a hydrophobic polyvinylidene fluoride (PVDF) membrane substrate. By testing the Janus membrane in direct contact MD experiments using feeds containing a sodium dodecyl sulfate (SDS) surfactant or/and mineral oil, we demonstrated that the dense Janus membrane can simultaneously resist wetting and fouling. This method represents the simplest approach to date for fabricating MD membranes with simultaneous wetting and fouling resistance. Importantly, we also unveil the mechanism of wetting resistance by measuring the breakthrough pressure and surfactant permeation (through the PVA layer) and found that wetting resistance imparted by a dense hydrophilic layer is attributable to capillary pressure. This new insight will potentially change the paradigm of fabricating wetting-resistant membranes and enable robust applications of MD and other membrane contactor processes facing challenges of pore wetting or/and membrane fouling.


Assuntos
Destilação , Purificação da Água , Membranas Artificiais , Águas Residuárias , Molhabilidade
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