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In this paper we present the results of an investigation of the influence of excess energy applied through ball milling on surface hydration behavior of alumina particles manufactured by three different methods. It is shown that different hydration amount are generated due to the defects and newly generated surfaces introduced during high energy ball milling processes. And the various gibbsite/bayerite ratio of the formed hydrates are attributed to the coordination defects resulting from heat treatment during the manufacturing process. As a result, it is confirmed that the dispersant works more efficiently with particles in which hydrates are formed, and the surfaces with structures closer to gibbsite seem to respond more effectively to dispersant in slurries. [ABSTRACT FROM AUTHOR]

To elucidate the microscopic mechanisms underlying the impact of hydrated cations on the surface hydration of slime mineral particles (specifically, kaolinite and quartz, the primary minerals in slime), this study focused on constructing two common hydrated cations in slime water: [Na(H2O)5]+ and [Ca(H2O)8]2+. Using density functional theory, the adsorption of these two hydrated cations on the surfaces of kaolinite (001), (\begin{document}$ 00\overline 1 $\end{document}) and α-quartz (001), as well as their competitive adsorption with water molecules were simulated. The simulation results revealed that the adsorption energy of hydrated cations on all three surfaces was over 50% lower than that of water molecules. The adsorption stability on mineral surfaces was as follows: α-quartz (001) surface > kaolinite (001) surface > kaolinite (\begin{document}$ 00\overline 1 $\end{document}) surface. The adsorption energy of the competitively stable configuration was 34%–57% lower than that of a single hydrated cation on kaolinite and quartz. Additionally, the [Ca(H2O)8]2+ configuration exhibited a greater stability than the [Na(H2O)5]+ configuration under both adsorption conditions. When the hydrated cations adsorbed onto three surfaces, strong hydrogen bonds formed with surface, surpassing the strength of hydrogen bonds between water molecules and kaolinite/quartz surfaces. The hierarchy of hydrogen bonds between two hydrated cations on mineral surfaces was as follows: kaolinite (001) surface > α-quartz (001) surface > kaolinite (\begin{document}$ 00\overline 1 $\end{document}) surface. Under a competitive adsorption, the hydrogen bond between [Na(H2O)5]+ and mineral surface strengthened, while the bond between [Ca(H2O)8]2+ and mineral surface weakened. Although hydrogen bonding did not entirely correlate with changes in adsorption energy, electrostatic interactions in the adsorption configuration were identified. The electrostatic interaction in the single adsorption configuration of hydrated cations proved stronger than that in water molecular adsorption. Under a competitive adsorption, the electrostatic interactions between hydrated cations and mineral surfaces intensified, with [Ca(H2O)8]2+ demonstrating stronger interaction than [Na(H2O)5]+. Given the robust adsorption of hydrated cations on the surfaces of kaolinite and quartz, the dehydration of slime particles becomes more challenging. This could increase hydration repulsion between particles, resulting in a more stable dispersion of particles in slime water.

The inhibition of surface hydration is the most fundamental technical measure for controlling shale borehole stability, but little research has been conducted on the inhibition of surface hydration. In this study, the low-molecular-weight amine inhibitor NH-2 was prepared. The inhibition performance of the NH-2 inhibitor was studied by linear expansion experiment, shale rolling recovery, isothermal adsorption, X-ray diffraction and thermogravimetric analysis. The inhibition mechanism was studied by X-ray diffraction and X-ray photoelectron spectroscopy. The results showed that 1 wt% NH-2 had a lower linear expansion ratio than did 5 wt% KCl and 1 wt% polyamine. The shale rolling recovery rate of the drilling fluid significantly improved after the addition of the NH-2 inhibitor. After the inhibitor NH-2 was added, the unit adsorbed water content of sodium montmorillonite decreased from 0.1104 g/g to 0.0331 g/g. The basal spacing of dry sodium montmorillonite increased from 1.01 nm to 1.3 nm, while that of wet sodium montmorillonite decreased from 1.9 nm to 1.31 nm. The DTG curve has only one low-temperature peak, and the sodium ion content in sodium montmorillonite was greatly reduced. These results showed that the NH-2 inhibitor has good inhibition performance. The inhibitor NH-2 enters the interlayer space of sodium montmorillonite through intercalation, displaces exchangeable cations, and minimizes the base spacing of sodium montmorillonite. Thus, the surface hydration of sodium montmorillonite was completely inhibited. In addition, the decomposition temperature of the NH-2 inhibitor was 232°C, which indicates good thermal stability. This study provides an inhibitor with high temperature resistance and efficient inhibition of hydration. [ABSTRACT FROM AUTHOR]

Borehole instability is one of the most complicated technical problems in oil and gas exploration and development.The hydration and expansion of clay minerals is the critical factor causing wellbore instability in which the surface hydration is difficult to be removed due to the large hydration potential.In this light, through molecular dynamic simulation, this paper probed into the CaCl2 inhibitory effect of concentrations, temperatures and pressures on the surface hydration of montmorillonite which revealed the macroscopic mechanism.Results indicated that inhibition of cations were achieved by binding water molecules on the surface of montmorillonite and decreasing the transport and conductivity of water molecules, thereby regulating the invasion of water molecules into the surface of montmorillonite.The ability of inorganic salts to inhibit surface hydration were CaCl2>NaCl>MgCl2>KCl.The study found that calcium ions easily adsorbed surface water molecules to form stable outer sphere complex.With the increase of CaCl2 concentration, coordination number, hydration number and hydration radius of calcium ion decreased, and the inhibitory effect diminished.When the temperature increased and the pressure decreased, the conductivity and transport capacity of water molecules was enhanced in the system, the coordination number of calcium ion descended, and mechanical strength declined.

To understand the research progress of molecular dynamics (MD) method in the field of clay minerals, the application of MD in the interface interaction of clay minerals is reviewed in this paper. MD simulations have become the indispensable means to study mineral interface effects. Clay minerals are common associated minerals with hydrophilic surface, the ease of argillization, negative electricity, and the ability of forming impurities and defects. They are widely concerned in the fields of mine wastewater treatment, fine clay mineral flotation, shale oil and gas exploitation, and so forth. In addition, clay minerals are considered as natural adsorbents due to their large specific surface area, but their complex interface interactions hinder their effective utilization. Therefore, it is particularly important to reveal the interaction mechanism of clay interface at the atomic/molecular level by means of software simulation technology. In this review, our focus is on the applications of MD method in the field of clay mineral interface interaction, such as clay/gas interface, clay/water interface, agents and clay/water interface, and mineral particle and clay/water interface. Furthermore, the history and shortcomings of MD simulation are summarized. The research and effective utilization of clay interface are summarized and prospected as well. [ABSTRACT FROM AUTHOR]

[Display omitted] Underwater oil-repellency of polyelectrolyte brushes has been attributed mainly to electric double-layer repulsion forces based on Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Many non-polyelectrolyte materials also exhibit oil-repellent behaviour, but it is not clear if there exist similar electric double-layer repulsion and if it is the sole mechanism governing their underwater oil-repellency. In this article, the oil-repellency of highly amorphous cellulose exhibiting is investigated in detail, through experiments and molecular dynamics simulations (MDS). It was found that the stable surface hydration on regenerated cellulose was due to a combination of long-range electrostatic repulsions (DLVO theory) and short-range interfacial hydrogen bonding between cellulose and water molecules (as revealed by MDS). The presence of a stable water layer of about 200 nm thick (similar to that of polyelectrolyte brushes) was confirmed. Such stable surface hydration effectively separates cellulose surface from oil droplets, resulting in extremely low adhesion between them. As a demonstration of its practicality, regenerated cellulose membranes were fabricated via electrospinning, and they exhibit high oil/water separation efficiencies (including oil-in-water emulsions) as well as self-cleaning ability. [ABSTRACT FROM AUTHOR]

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In this study, the effects of Fe3+ doping on the crystal structure and surface properties of quartz were analyzed using density functional theory (DFT) calculations and molecular dynamics (MD) simulations. The crystal structure, surface model, and adsorption model of the water molecule layer for Fe3+-doped α-quartz were established. The DFT calculations reveal that Fe3+ doping affects the α-quartz lattice parameters and surface active sites. The adsorption energy near the sites occupied by Fe3+ is −66.20 kJ/mol, which is considerably lower than that of the undoped system (−42.35 kJ/mol). This makes it easier for water molecules to be adsorbed on the Fe3+-doped α-quartz (001) surface. The frontier orbital energy, electron density difference, charge density, and Mulliken bond population analyses indicate that the presence of Fe3+ improves the ability of the (001) surface of α-quartz to attract and bind water molecules. This improvement is mainly due to the formation of hydrogen bonds between the surface hydroxyl groups and water molecules on the surface of Fe3+-doped quartz and the equilibrium of the electrostatic interaction between the cation and water molecules. MD simulations show that a hydration layer with a thickness of approximately 8 Å is formed on the surface of Fe3+-doped α-quartz. Compared with the undoped system, the hydration film on the surface of the doped system is thicker, indicating that the incorporation of Fe3+ impurities in the lattice enhances the surface hydration characteristics of quartz. These results offer theoretical guidance for achieving efficient separation and thorough purification of quartz. [Display omitted] • A quartz crystal and surface model with lattice iron impurities are established. • The adhesion mechanism of water molecules to the surface of Fe3+ doping quartz is elucidated. • The adsorption of water molecules on the Fe3+ doping α-quartz surface is primarily governed by hydrogen bonding and electrostatic interactions. • Molecular dynamics calculations show that Fe3+ doping improves the hydration characteristics of the α-quartz surface. [ABSTRACT FROM AUTHOR]

Applying electric fields to promote water/oil recovery efficiency is gaining increasing attention in downstream of heavy oil development. In this work, molecular dynamics simulations were performed to study the motion of N-(1-Hexylheptyl)-N′-(5-carboxylicpentyl) perylene-3,4,9,10-tetracarboxylic bisimide (C5Pe) between kaolinite (Kaol) surfaces mediated by external electric field in water under different pH. Aggregation of C5Pe was mainly mediated by pH and not affected by the electric field, while adsorption responded to both pH and the electric field. In neutral and alkaline solutions, C5Pe was deprotonated, and its distribution between two Kaol surfaces was mainly mediated by the Coulombic force exerted by the electric field. In acidic solutions, C5Pe carried zero charge, and yet its distribution was still affected by the electric field. The external electric fields mediated the wettability of the two Kaol surfaces in different extents, and C5Pe preferred to adsorb on the more hydrated surface. The mediation of the electric fields on the wettability of surfaces was achieved in two stages. In the first stage, when the electric field of a low strength was applied, diffusion of water enhanced. The hydration of both Kaol surfaces became increased as water molecules formed more hydrogen bonds with the surfaces. As the electric field strength became sufficiently high, diffusion showed no further enhancement, and the re-orientation of water dipoles started dominating the hydrogen bonding with the surfaces. Carrying opposite charges, the hydrogen bond donors and acceptors of water were differently regulated by the electric field, and therefore water molecules conformed in a certain manner under the electric field of high strength. As a result, the hydrogen bonding between water and the two Kaol surfaces (placed on two sides of the simulated box under the electric field) varied with their positions. Due to the structural hindrance of the hydroxyl groups on the surface, the surface could provide more hydrogen bonding donors formed more hydrogen bonds with water, and thus became more hydrophilic and had stronger attraction to C5Pe. • pH affected C5Pe aggregation (face-to-face stacking) via mediating the carboxylate group status. • Electric fields could mediate the adsorption of neutral C5Pe adsorption on kaolinite surface. • Regulation of electric fields on kaolinite wettability varied with acceptor/donor sites on the surface [ABSTRACT FROM AUTHOR]

The commonly used oxide-supported metal catalysts are usually prepared in aqueous phase, which then often need to undergo calcination before usage. Therefore, the surface hydration and dehydration of oxide supports are critical for the realistic modeling of supported metal catalysts. In this work, by ab initio molecular dynamics (AIMD) simulations, the initial anhydrous monoclinic ZrO2( 1 ¯ 11) surfaces are evaluated within explicit solvents in aqueous phase at mild temperatures. During the simulations, all the two-fold-coordinated O sites will soon be protonated to form the acidic hydroxyls (HOL), remaining the basic hydroxyls (HO*) on Zr. The basic hydroxyls (HO*) can easily diffuse on surfaces via the active proton exchange with the undissociated adsorption water (H2O*). Within the temperatures ranging from 273 K to 373 K, in aqueous phase a certain representative equilibrium hydrated m-ZrO2( 1 ¯ 11) surface is obtained with the coverage (θ) of 0.75 on surface Zr atoms. Later, free energies on the stepwise surface water desorption are calculated by density functional theory to mimic the surface dehydration under the mild calcination temperatures lower than 800 K. By obtaining the phase diagrams of surface dehydration, the representative partially hydrated m-ZrO2( 1 ¯ 11) surfaces (0.25≤θ<0.75) at various calcination temperatures are illustrated. These hydrated m-ZrO2( 1 ¯ 11) surfaces can be crucial and readily applied for more realistic modeling of ZrO2 catalysts and ZrO2-supported metal catalysts. [ABSTRACT FROM AUTHOR]

Zwitterionic polymers as crucial antifouling materials exhibit excellent antifouling performance due to their strong hydration ability. The structure–property relationship at the molecular level still remains to be elucidated. In this work, the surface hydration ability of three antifouling polymer membranes grafting on polysiloxane membranes Poly(sulfobetaine methacrylate) (T4-SB), poly(3-(methacryloyloxy)propane-1-sulfonate) (T4-SP), and poly(2-(dimethylamino)ethyl methacrylate) (T4-DM) was investigated. An orderly packed, and tightly bound surface hydration layer above T4-SP and T4-SB antifouling membranes was found by means of analyzing the dipole orientation distribution, diffusion coefficient, and average residence time. To further understand the surface hydration ability of three antifouling membranes, the surface structure, density profile, roughness, and area percentage of hydrophilic surface combining electrostatic potential, RDFs, SDFs, and noncovalent interactions of three polymers' monomers were studied. It was concluded that the broadest distribution of electrostatic potential on the surface and the nature of anionic SO3- groups led to the following antifouling order of T4-SB > T4-SP > T4-DM. We hope that this work will gain some insight for the rational design and optimization of ecofriendly antifouling materials. [ABSTRACT FROM AUTHOR]

The development of shale gas reservoirs with water-based drilling fluids is complicated by the problem of clay mineral hydration. The method of molecular simulation is widely used in many research fields, in both humanitarian and material sciences. In this paper, based on the previously published studies, the authors propose a comprehensive review of molecular simulation of inhibiting the surface hydration swelling of clay minerals. Swelling characteristics and the adsorption properties of clay minerals are reviewed and discussed. The results can be useful for future development of the MD (molecular dynamics) simulation method and its application in studies of inhibition of the surface hydration swelling in clay minerals. [ABSTRACT FROM AUTHOR]

Purpose: Numerous clinical findings support the idea that increased surface laryngeal hydration prevents and manages voice problems in professional voice users. However, empirical evidence for surface laryngeal hydration (nebulized saline solution) through multidimensional voice measures is lacking, especially in speech-language pathologists (SLPs). Hence, the present study investigated the effect of surface hydration using nebulized saline solution on voice quality using thermal, acoustic, and self-perceptual measures in SLPs., Methods: The study involved 30 SLPs divided into three groups: group I had no voice usage, group II read aloud passage for 1 hour without surface hydration, and group III read aloud passage for 1 hour with surface hydration for 10 minutes. Multidimensional voice outcomes such as thermal (front, right, and left view of the throat), acoustic (Multidimensional Voice Program), and self-perceptual (perceived phonatory effort, perceived vocal tiredness) were measured for the pretest and post test condition in all the group., Results: Pre-post comparison shows that thermal measures showed a significant increase in group II and a significant decrease in group III. Also, fundamental frequency, perturbation, and self-perceptual measures showed a significant increase in group II compared to group III. Further, the between-group post test comparisons revealed a significant decrease in many outcome measures in group III compared to group II. The above results support that surface hydration significantly influenced the voice quality during the vocal loading task., Conclusion: The study confirms the benefits of surface hydration using saline solution in SLPs. Surface hydration preserves vocal quality compared to those not hydrated during vocal loading., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2024 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

The aim of the work was to study the peculiarities of interaction of the surface of bacterial lectin of Bacillus subtilis IMB B-7724 inthe native state and under different model conditions with water molecules by ¹ H NMR; to create a composite system based on the studied lectin, in which the protein molecule is minimally affected by the surface of the carrier, because protein molecules are capable to bind a significant amount of water localized in the spaces between the polymer chains. A method of “dry” immobilization of bacterial lectin on the surface of hydrophobic silica has been developed.Hydration of native lectin and lectin fixed on the surface of hydrophobic silica AM-1-175 was studied by low-temperature ¹ H NMR spectroscopy. It has been shown that the immobilization of lectin on the surface of AM1 is accompanied by an increase in the interfacial energy gS from 4.1 to 5.2 J/g. This is due to an increase in the concentration of strongly bound water. Analysis of changes in the distributions of radii R of clusters of adsorbed water allows us to state that in water adsorbed by native lectin, there are two main maxima at R = 1 and 3 nm. In the immobilized state, the maximum at R = 1 nm is present in both types of water (of different order), but the second maximum is observed only for more ordered associates.Chloroform medium slightly reduces the binding energy of water to native lectin molecules (from 4.3 to 4.1 J/g), but in the case of immobilized lectin in CDCl3 medium, the value of ΣgS increases from 5.2 to 7.4 J/g. That is, the weakly polar medium promotes to increase in the interaction of water with interfaces, which is manifested in a relative increase in the number of water clusters of smaller size (Fig. 4). It should be noted that weakly associated forms of water (signal 3) are also represented by several types of clusters that have a radius in the range R = 1–10 nm, and their size distribution changes significantly during immobilization of lectin on the surface of AM1. Probably, weakly associated types of water are formed both in cavities, between polymer chains of protein molecules, and on the surface of AM1, free of protein. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanism of xanthate adsorption on hydrated ZnS is understood by QCM-D and DFTB+. • Adsorption of water is more favorable than EX/BX on unactivated ZnS. • Existence of water's lone pair electrons increases hydrophobicity of activated ZnS. • Interaction of EX/BX with hydrated, activated ZnS surface is chemisorption. • Higher reactivity of Cu+ d orbitals & orbital symmetry matching led to the results. The mechanism of surface hydration and xanthate adsorption in the flotation of unactivated/Cu-activated sphalerite is still controversial. Therefore, a study combining in-situ measurement and quantum simulation is employed to investigate the interaction mechanism of ethyl xanthate (EX) and butyl xanthate (BX) on the fully hydrated, unactivated/Cu-activated sphalerite surfaces at solid–liquid interfaces. Density functional based on tight-binding (DFTB+) and molecular dynamics (MD) results suggest that the Cu-activated surface is hydrophobic with the first layer of water being distributed more disorderly on it. This is due to the difficulty of the lone pair electrons of water to interact with Cu. On the unactivated surface, water adsorption is more favorable than xanthates, hence, water molecules are physically adsorbed on it. Whereas the interaction of EX/BX with the hydrated, activated surface is chemisorption. The higher reactivity of Cu+ d orbitals to form π-backbonds with xanthate and the orbital symmetry matching of the Cu d yz orbitals and xanthate p z orbitals contribute to these results. Microcalorimetric results also demonstrate that copper activation enhances the exothermic heat and reaction rate, facilitating the interaction of EX/BX with sphalerite. These are consistent with the flotation and quartz crystal microbalance with dissipation (QCM-D) results. [ABSTRACT FROM AUTHOR]

The pH of flotation slurry directly affects the surface potentials of mineral particles and bubbles, and therefore the hydration of coal surface and the mineralization process of flotation. In this paper, the effect of pH on the surface potential, hydration degree, and floatability of lignite particles was studied, wherein Einstein’s dispersion viscosity theory was adopted to calculate the hydration degree, and DLVO theory was used to estimate the interaction between coal particles and oily bubbles. The effect of pH on the lignite floatability was evaluated in terms of induction time and oily-bubble flotation results. The results showed that with increasing pH, the zeta potentials of coal particles and oily bubbles decrease, causing a 37.89% increase in the coal surface hydration from pH 3 to pH 11. As a result, the energy barrier for attachment between the coal particles and oily bubbles reaches the maximum value of 2.669 × 10−16 J at pH 11, resulting in low attachment efficiency. Correspondingly, the combustible matter recovery of oily-bubble flotation is significantly decreased from 57.76% to 28.00%. [ABSTRACT FROM AUTHOR]

Surface charges and hydration are predominant properties of colloidal particles that govern colloidal stability in aqueous suspensions. These properties usually coexist and interact with each other. The correlation between the surface charge and hydration of minerals is summarized on the basis of innovative experimental, theoretical, and molecular dynamics simulation studies. The factors affecting the adsorption behavior of ions and water molecules, such as ion concentration, ion hydration radius and valence, and surface properties, are discussed. For example, the hydration and adsorption states completely differ between monovalent and divalent ions. For ions of the same valence, the effect of surface charge on the hydration force follows the Hofmeister adsorption series. Electrolyte concentration exerts a significant effect on the hydration force at high ion concentrations. Meanwhile, the ion correlations in high-concentration electrolyte systems become long range. The interfacial water structure largely depends on surface chemistry. The hydration layer between different surfaces shows large qualitative differences. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We investigate the surface hydration of kaolinite particles. • We calculate single water molecule adsorption on kaolinite surfaces with DFT. • We simulate hydration characteristics of kaolinite surfaces with MD. • Hydration layer of kaolinite is mainly composed of about 3 layers of water molecules. • The hydration mechanism of kaolinite surface is hydrogen bonding. Abstract The surface hydration is one of the main reasons for the difficulty of coal slurry water sedimentation and dewatering, the Density functional theory (DFT) and Molecular dynamics (MD) simulations on the surface hydration of kaolinite were investigated in this study. The results indicate that the adsorption of single water molecule on kaolinite (0 0 1) surface and (0 0 1 ¯ ) surface mainly by forming hydrogen bonds, and the adsorption energies of single water molecule on different initial positions of kaolinite (0 0 1) surface are −72.12 to −19.23 kJ/moL, less than that of kaolinite (0 0 1 ¯ ) surface with −19.23 to −5.77 kJ/moL, which mean that the water molecule preferentially adsorption on kaolinite (0 0 1) surface. The binding force between kaolinite surfaces and water molecules decreased with the increase of water coverage rate (or the number of water molecules), the hydrogen-bond interaction on kaolinite/water interface gradually weakened, and the water molecules on hydrophilic kaolinite surfaces can be gradually formed 3 layers of water molecules. The hydrated film of kaolinite surface is mainly composed of about 3 layers of water molecules, and its thickness is about 8–10 Å. The hydration mechanism of kaolinite surface is mainly that the water molecules at kaolinite interface are adsorbed on surface with hydrogen bonds, and a hydrated film composed of multiple water molecules is gradually formed on kaolinite surface with the increase of water coverage rate. [ABSTRACT FROM AUTHOR]

Inhibiting the surface hydration of clay is the main task for the water-based drilling fluids used in the development of shale gas. Branching polyethyleneimine (BPEI) completely inhibits the clay surface hydration. However, the use of BPEI is limited by its high toxicity. In this paper, BPEI was modified by grafting with hydroxyethyl groups to reduce the toxicities of BPEI hydration inhibitors. The structures and properties of the modified BPEI were characterized by infrared spectroscopy, mass spectrometry, the luminescent bacteria method, isothermal adsorption, X-ray diffraction, thermogravimetric analysis, contact angle measurement, scanning electron microscopy, X-ray photoelectron spectroscopy and molecular simulations. The relative luminescence rate of the modified BPEI inhibitors increased from 14 % to 62 % with increases in the number of grafted hydroxyethyl groups. After hydrated sodium montmorillonite (Na–Mt) contacted the modified BPEI inhibitors, the basal spacings of the Na–Mt decreased from 1.90 nm to a minimum of 1.40 nm, and the DTG curve had only one low-temperature peak. Molecular simulations showed that the energy for adsorption of the inhibitor on the Mt surface increased with increases in the number of grafted hydroxyethyl groups. These results suggested a structure-activity relationship for inhibition and the biological toxicity of the modified BPEI inhibitor. That is, within the range of 20:1 to 5:1 for the molar ratios of amino and hydroxyl groups, increases in the number of grafted hydroxyethyl groups gradually decreased the biological toxicities of BPEI inhibitors, and the inhibition performance was gradually enhanced. BPEI-OH4 (amino:hydroxyl = 5:1) showed the best performance among the modified BPEI inhibitors. This provides an excellent inhibitor and a low-toxicity modification method, which will facilitate the development of environmentally friendly high-performance water-based drilling fluids. • The biotoxicity of BPEI was effectively reduced by grafting of hydroxyethyl groups. • The inhibition efficiency of BPEI was improved by grafting of the hydroxyethyl groups. • The adsorption capacity of BPEI was improved by grafting with different numbers of hydroxyethyl groups. • These results provide a way to decrease the toxicities of amino inhibitors without weakening the inhibition performance. [ABSTRACT FROM AUTHOR]

Water is a molecule always present in the reaction environment in photocatalytic and biomedical applications of TiO2 and a better understanding of its interaction with the surface of TiO2 nanoparticles is crucial to develop materials with improved performance. In this contribution, we first studied the nature and the surface structure of the exposed facets of three commercial TiO2 samples (i.e., TiO2 P25, SX001, and PC105) by electron microscopy and IR spectroscopy of adsorbed CO. The morphological information was then correlated with the water adsorption properties, investigated at the molecular level, moving from multilayers of adsorbed H2O to the monolayer, combining medium- and near-IR spectroscopies. Finally, we assessed in a quantitative way the surface hydration state at different water equilibrium pressures by microgravimetric measurements.

The interaction between drilling fluid and shale has a significant impact on wellbore stability during shale oil and gas drilling operations. This paper investigates the effects of the drilling fluid activity on the surface and osmotic hydration characteristics of shale. Experiments were conducted to measure the influence of drilling fluid activity on surface wettability by monitoring the evolution of fluid-shale contact angles. The relationship between drilling fluid activity and shale swelling ratio was determined to investigate the osmotic hydration behavior. The results indicate that, with increasing drilling fluid activity, the fluid−shale contact angles gradually increase—the higher the activity, the faster the adsorption rate; and the stronger the inhibition ability, the weaker the surface hydration action. The surface adsorption rate of the shale with a KCl drilling fluid was found to be the highest. Regarding the osmotic hydration action on the shale, the negative extreme swelling ratio (b) of the shale was found to be: bKCl < bCTAB < bSDBS. Moreover, based on the relationship between the shale swelling ratio and drilling fluid activity, shale hydration can be divided into complete dehydration, weak dehydration, surface hydration, and osmotic hydration, which contributes to the choice of drilling fluids to improve wellbore stability.

The surface hydration of shale has severe effect on the wellbore stability during drilling through the shale formation. In this paper, a novel method was developed to measure wettability of shale power by determining real contact angle. A variety of methods including measurements of Zeta potential, uniaxial compressive strength, shale stability indexes, surface hydration water, linear swelling, and cuttings hot-rolling dispersion experiment were used to evaluate the inhibition of surfactants. Meanwhile, Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD) were used to investigate the interaction between surfactants and shale particles. Results revealed that the surface hydration of shale could be inhibited by using suitable surfactants. The surfactants compound of PA and THAO possessed stronger surface hydrating inhibition and capacity of restraining osmotic hydration. This is because the compound can enhance the surface hydrophobicity after adsorption onto the surface of shale particles, restrained osmotic hydration through swapping out inorganic cations in the clay interlayer, thus reducing the zeta potential and bounding clay gall together. [ABSTRACT FROM AUTHOR]

Synthetic hydroxyapatite (HAp) is used clinically as a material for bone prostheses owing to its good bone-bonding ability; however, it does not contribute to bone remodeling. Carbonate-substituted hydroxyapatite (CAp) has greater bioresorption capacity than HAp while having similar bone-bonding potential, and is therefore considered as a next promising material for bone prostheses. However, the effects of the CAp instability on inflammatory and immune responses are unknown in detail. Here, we show that the surface layer of CAp is more hydrated than that of HAp and induces changes in the shape and function of macrophage-like cells. HAp and CAp were synthesized by wet method and molded into disks. The carbonate content of CAp disks was 6.2% as determined by Fourier transform (FT) infrared spectral analysis. Diffuse reflectance infrared FT analysis confirmed that physisorbed water and surface hydroxyl groups (OH−) were increased whereas structural OH− was decreased on the CAp as compared to the HAp surface. The degree of hydroxylation in CAp was comparable to that in bone-apatite structures, and the CAp surface exhibited greater hydrophilicity and solubility than HAp. We investigated immune responses to these materials by culturing RAW264 cells (macrophage precursors) on their surfaces. Cell spreading on the CAp disk was suppressed and the secretion level of inflammatory cytokines was reduced as compared to cells grown on HAp. These results indicate that the greater surface hydration of CAp surface can attenuate adverse inflammatory responses to implanted bone prostheses composed of this material. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1063-1070, 2017. [ABSTRACT FROM AUTHOR]

Summary Objectives Vocal loading tasks provide insight regarding the mechanisms underlying healthy laryngeal function. Determining the manner in which the larynx can most efficiently be loaded is a complex task. The goal of this study was to determine if vocal loading could be achieved in 30 minutes by altering phonatory mode. Owing to the fact that surface hydration facilitates efficient vocal fold oscillation, the effects of environmental humidity on vocal loading were also examined. This study also investigated whether the detrimental effects of vocal loading could be attenuated by increasing environmental humidity. Methods Sixteen vocally healthy adults (8 men, 8 women) completed a 30-minute vocal loading task in low and moderate humidity. The order of humidities was counterbalanced across subjects. The vocal loading task consisted of reading with elevated pitch and pressed vocal quality and low pitch and pressed and/or raspy vocal quality in the presence of 65 dB ambient, multi-talker babble noise. Results Significant effects were observed for (1) cepstral peak prominence on soft sustained phonation at 10th and 80th pitches, (2) perceived phonatory effort, and (3) perceived tiredness ratings. No loading effects were observed for cepstral peak prominence on the rainbow passage, although fundamental frequency on the rainbow passage increased post loading. No main effect was observed for humidity. Conclusions Following a 30-minute vocal loading task involving altering laryngeal vibratory mode in combination with increased volume. Also, moderate environmental humidity did not significantly attenuate the negative effects of loading. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: To investigate the effects of steam inhalation using a facial steamer on voice quality-related acoustic measures.Study Design: Prospective outcome research: single-blinded experimental study.Methods: Forty-five vocally healthy female subjects ranging in age from 18 to 30 years (Mean age: 22.41 years; standard deviation [SD]: 8.91) participated in the study. Phonation samples were recorded under three different conditions in triplicate: baseline recording, immediately after mouth breathing (dehydration), and immediately after 3 minutes of steam inhalation via the mouth (rehydration).Results: In the initial voice recording (prior to dehydration), mean jitter (0.42 %; SD: 0.07), shimmer (2.20 dB; SD: 0.45), and harmonics-to-noise ratio (HNR) (21.60; SD: 2.41) values were within normal limits. After short-term mouth breathing (dehydration, approximately 10 minutes), the mean jitter (1.57 %; SD: 1.82) and shimmer (4.73 dB; SD: 1.83) were significantly increased (P < 0.05), and HNR (18.64; SD: 3.16) was reduced (P < 0.05). After steam inhalation (rehydration) for 3 minutes, mean jitter (0.48 %; SD: 0.12) and shimmer (2.70 dB; SD: 0.71) showed significant decrease (P < 0.05), and HNR (20.10; SD: 3.69) showed significant increase (P < 0.05). All parameters statistically significantly improved from post dehydration values.Conclusion: The simple procedure of steam inhalation using a facial steamer displayed positive effects on parameters proposed to reflect voice quality.Level Of Evidence: 4. Laryngoscope, 126:2305-2309, 2016. [ABSTRACT FROM AUTHOR]

By means of Monte Carlo computer simulations in the isothermal-isobaric ensemble, we investigated the interaction of a hydrophobic ligand with the hydrophobic surfaces of various curvatures (planar, convex and concave). A simple two-dimensional model of water, hydrophobic ligand and surface was used. Hydration/dehidration phenomena concerning water molecules confined close to the molecular surface were investigated. A notable dewetting of the hydrophobic surfaces was observed together with the reorientation of the water molecules close to the surface. The hydrogen bonding network was formed to accommodate cavities next to the surfaces as well as beyond the first hydration shell. The effects were most strongly pronounced in the case of concave surfaces having large curvature. This simplified model can be further used to evaluate the thermodynamic fingerprint of the docking of hydrophobic ligands. [ABSTRACT FROM AUTHOR]

Objectives The larynx is susceptible to irradiation, which causes significant vocal fold (VF) edema and dehydration shortly after radiotherapy for head and neck cancers. However little is known about radiation-induced damage to VF liquid homeostasis. To evaluate the effects of irradiation on VF hydration and lubrication, we investigated changes in water transporters (aquaporins [AQPs]) and mucin production in vivo and ex vivo, as well as morphometric changes in the laryngeal mucosa and glands of irradiated rat larynges. Study Design Animal study. Materials and Methods Local irradiation at 18 Gy was delivered to rat larynges. Histologic changes in laryngeal mucosa and glands were observed by light microscopy, and the distributions of AQPs and mucin were investigated by immunofluorescence staining 3 months after irradiation. Early effects on gene regulation of AQPs and mucin were evaluated by quantitative real-time polymerase chain reaction of the extirpated VFs and subglottic laryngeal mucosa at 12, 24, and 72 hours after irradiation. Results Laryngeal glands exhibited severe atrophic changes and showed decreased density throughout the irradiated larynx. The expression of AQP1, 4, 5, and mucin in VFs, as well as AQP5 and mucin in submucosal laryngeal glands, decreased significantly 3 months after irradiation. An ex vivo study revealed that the gene expression of AQP5 in VF tissues was significantly downregulated at 12 hours postirradiation. Conclusion Laryngeal irradiation induces damage in laryngeal mucosal barriers and alters laryngeal liquid homeostasis, which may be one reason for vocal dysfunction following irradiation. Level of Evidence N/A. Laryngoscope, 125:1900-1907, 2015 [ABSTRACT FROM AUTHOR]

The flotation separation of water-soluble salt minerals has to be conducted under the condition of saturation in brines which represents a challenging but exciting topic of colloid and surface chemistry. Despite several proposals on explaining the success of this industrial application for many decades, our understanding of the flotation separation is still far from complete yet, owing to the complexity of the highly selective collection of salt crystals by air bubbles in brines. Here, we thoroughly review the experimental results for halogen, oxyanion, and double salts and match them with the proposed theories on the flotation of soluble salts to identify the agreed and disagreed cases. The experimental results show that the flotation of these salts varies from collectors (surfactants applied to control the crystal hydrophobicity) to collectors and is strongly affected by the brine ion composition and pH conditions. We find some exceptional flotation results that cannot be simply explained by the crystal surface charge and wettability. Furthermore, we outline several disputes and discrepancies between the experiments and the theories when different collectors are applied. Apart from the extensive consideration of surface hydration, the presence of external ion species exhibits ubiquitous effects on the surface properties of salt crystals and the colloidal properties of collectors. We conclude that the interactions between salt ions, water molecules, collectors, and salt crystals must be considered more thoroughly, and the activity of collectors at the air-liquid interface should also be the focus. Advanced techniques such as molecular dynamics simulation, atomic force microscopy, X-ray photoelectron spectroscopy, and sum-frequency generation spectroscopy are expected to be promising research tools for future studies. [Display omitted] • Flotation of soluble salt minerals in various brine conditions is reviewed. • Surface chemical properties of soluble salt minerals are presented. • Merits and demerits of current collector adsorption theories are described. • Perspectives and future investigations of salt flotation chemistry are proposed. [ABSTRACT FROM AUTHOR]

• In situ growth of MOF–303 on polymeric nanofibers. • Water-absorbing MOF–303 induces the surface hydration of polymeric nanofibers. • Hydrated surfaces improve the electrostatic trapping of polar PMs. • The efficient removal properties of ultrafine PMs are achieved. Air pollution, particularly from particulate matters (PMs), has become a serious global issue. Thus, there are increasing demands for improving PM filtering systems for public safety. Here, we have first demonstrated that the surface hydration of electrospun fiber-based filters significantly improves capturing ability of ultrafine PM 0.3 (PMs having a diameter of ∼ 0.3 µm). Aluminum-based metal–organic framework (MOF)–303, which is uniformly coated on the surface of polyimide nanofibers (PI NFs), provides sufficient surface hydration with PI NFs due to its high-water uptake capability, resulting in favorable trapping sites for polar molecules or particles in the air. Furthermore, the MOF–303-coated PI NF (PI@MOF–303) filters show relatively low pressure drops, which can be attributed to increasing fiber diameters after MOF–303 coating, resulting from enlarged spaces between fibers. Consequently, the PI@MOF–303 filters afford highly efficient PM 0.3 removal properties (95.70%) and low pressure drop (ΔP = 36.73 Pa). Our strategy offers new insights into the fabrication of high-performance electrospun fiber-based filters with desirable properties for filtering PMs. [ABSTRACT FROM AUTHOR]

This work focuses on the study of the hydration phenomenon operating in Na–mordenite membranes during the conditioning step (stabilisation of filtration properties). First, experimental (filtration of pure water) tests are carried out immediately after putting the membrane in its casing and until the stabilization of the membrane permeation flux. The evolution of the hydraulic permeability shows that there are two separate steps during the conditioning of the membrane. A numerical approximation of the hydraulic permeability during the conditioning step was carried out. The first part of the equation expresses a fast decrease in the membrane's permeability during the beginning of the conditioning step (several hours). This behaviour is attributed to a surface hydration of the membrane and also to a modification of the crystalline framework. The second one is a slower phenomenon that takes place until the end of the conditioning step. It is attributed to the (intra-crystalline) hydration of micropores. [ABSTRACT FROM AUTHOR]

The connection between antifouling and surface hydration is a fascinating but daunting question to answer. Herein, we use molecular dynamics (MD) computer simulations to gain further insight into the role of surface functionalities in the molecular-level structuration of water (surface kosmotropicity) – within and atop subnanometric organosilane adlayers that were shown in previous experimental work to display varied antifouling behavior. Our simulations support the hypothesized intimate link between surface hydration and antifouling, in particular the importance of both internal and interfacial hydrophilicity and kosmotropicity. The antifouling mechanism is also discussed in terms of surface dehydration energy and water dynamicity (lability and mobility), notably the crucial requirement for clustered water molecules to remain tightly bound for extensive periods of time – i.e. exhibit slow exchange dynamics. A substrate effect on surface hydration, which would also participate in endowing antifouling adlayers with hydrogel-like characteristics, is also proposed. In contrast, the role of adlayer flexibility, if any, is assigned a secondary role in these ultrathin structures made of short building blocks. The conclusions from this work are well in line with those previously drawn in the literature. [ABSTRACT FROM AUTHOR]

Abstract: Two types of ball milling methods, wet planetary ball milling and dry tumbling ball milling, were used to grind fused silica powders for the preparation of silica-based suspensions in this experiment. The effect of surface hydration and particle shape caused by the two milling methods on the slurry rheology was investigated. The results showed that, with similar particle size distribution, the viscosity of the suspensions prepared from the powders milled by wet ball milling ranged from 275mPas to 311mPas within 20min and the suspension exhibited a continuous shear thickening behaviour whereas the viscosity of the suspensions prepared from the powders milled by dry ball milling ranged from 69mPas to 74mPas and the suspension exhibited a shear thinning behaviour first, and then exhibited a slightly shear thickening behaviour. The reasons were attributed to the differences in surface hydration and particle shape. It was postulated that the two factors affected the slurry rheology through the modification of particle interactions during the flow of high concentration suspensions. [Copyright &y& Elsevier]