Cation Hydration Research Articles

Water adsorption isotherms on soil external particle surface by molecular simulation

Water adsorption isotherm describes soils’ ability in retaining water under given relative humidity and isothermal conditions, and is frequently utilized to characterize soils’ engineering properties. Fundamentally, the water adsorption isotherm on soil external particle surface is the macroscopic manifestation of atomistic scale soil–water interaction mechanisms, including van der Waals, surface hydration, cation hydration, and electrical double layer. Yet, the quantitative link between these mechanisms and water adsorption isotherms remains obscure, and it still lacks effective approaches to probe these mechanisms. Here, a general framework based on Grand Canonical Monte Carlo simulation was developed to directly obtain water adsorption isotherms on soil external particle surface from the interatomic potentials. The simulated adsorption isotherm agrees well with existing experimental and numerical results, confirming the validity of the proposed framework. The proposed framework facilitates a quantitative assessment of the impact of atomistic scale soil–water interaction mechanisms on the macroscale water adsorption isotherms. It reveals that the atomistic scale soil–water interaction mechanisms dictate the shape of adsorption isotherms, i.e., an ‘S’ shape by prevailing cation hydration and a concave shape by prevailing surface hydroxyl hydration; and divalent cations exhibit a much more intensive interaction with water molecules than univalent cations, increasing the adsorption capacity up to 9.5 times.

Hydration of Heavy Alkaline-Earth Cations Studied by Molecular Dynamics Simulations and X-ray Absorption Spectroscopy.

The physicochemical properties of the three heaviest alkaline-earth cations, Sr2+, Ba2+, and Ra2+ in water have been studied by means of classical molecular dynamics (MD) simulations. A specific set of cation–water intermolecular potentials based on ab initio potential energy surfaces has been built on the basis of the hydrated ion concept. The polarizable and flexible model of water MCDHO2 was adopted. The theoretical–experimental comparison of structural, dynamical, energetic, and spectroscopical properties of Sr2+ and Ba2+ aqueous solutions is satisfactory, which supports the methodology developed. This good behavior allows a reasonable reliability for the predicted Ra2+ physicochemical data not experimentally determined yet. Simulated extended X-ray absorption fine-structure (EXAFS) and X-ray absorption near-edge spectroscopy spectra have been computed from the snapshots of the MD simulations and compared with the experimental information available for Sr2+ and Ba2+. For the Ra2+ case, the Ra L3-edge EXAFS spectrum is proposed. Structural and dynamical properties of the aqua ions for the three cations have been obtained and analyzed. Along the [M(H2O)n]m+ series, the M–O distance for the first-hydration shell is 2.57, 2.81, and 2.93 Å for Sr2+, Ba2+, and Ra2+, respectively. The hydration number also increases when one is going down along the group: 8.1, 9.4, and 9.8 for Sr2+, Ba2+, and Ra2+, respectively. Whereas [Sr(H2O)8]2+ is a typical aqua ion with a well-defined structure, the Ba2+ and Ra2+ hydration provides a picture exhibiting an average between the ennea- and the deca-hydration. These results show a similar chemical behavior of Ba2+ and Ra2+ aqueous solutions and support experimental studies on the removal of Ra-226 of aquifers by different techniques, where Ra2+ is replaced by Ba2+. A comparison of the heavy alkaline ions, Rb+ and Cs+, with the heavy alkaline-earth ions is made.

Investigation of NO adsorption and desorption phenomena on a Pd/ZSM-5 passive NOx adsorber

Pd-based zeolite materials have gained significant attention as passive NOx adsorbers (PNAs) for diesel-engine cold-start NOx mitigation due to their ability to store NOx at low temperatures. Pd/ZSM-5 is a promising PNA candidate, however, the NO adsorption mechanism over this material is not well understood. This study combines flow reactor experiments and surface spectroscopy to investigate NO adsorption under a variety of conditions. The state of hydration of the Pd cations played an important role in determining the impact of H2O and CO concentration on the PNA performance. Below 150 °C, the inhibition effect of H2O on NO adsorption was mitigated by CO. Due to dehydration, neither H2O nor CO had an impact on NO uptake at 150 °C, where maximum NO storage capacity of the PNA was also observed. The observed gas composition and temperature effects on NO adsorption and formation of surface intermediates ultimately inform a proposed mechanism.

Molecular Dynamics Simulation of Clay Hydration Inhibition of Deep Shale

In the process of the exploitation of deep oil and gas resources, shale wellbore stability control faces great challenges under complex temperature and pressure conditions. It is difficult to reflect the micro mechanism and process of the action of inorganic salt on shale hydration with the traditional experimental evaluation technology on the macro effect of restraining shale hydration. Aiming at the characteristics of clay minerals of deep shale, the molecular dynamics models of four typical cations (K+, NH4+, Cs+ and Ca2+) inhibiting the hydration of clay minerals have been established by the use of the molecular dynamics simulation method. Moreover, the micro dynamics mechanism of typical inorganic cations inhibiting the hydration of clay minerals has been systematically evaluated, as has the law of cation hydration inhibition performance in response to temperature, pressure and ion type. The research indicates that the cations can promote the contraction of interlayer spacing, compress fluid intrusion channels, reduce the intrusion ability of water molecules, increase the negative charge balance ability and reduce the interlayer electrostatic repulsion force. With the increase in temperature, the inhibition of the cations on montmorillonite hydration is weakened, while the effect of pressure is opposite. Through the molecular dynamics simulation under different temperatures and pressures, we can systematically understand the microcosmic dynamics mechanism of restraining the hydration of clay in deep shale and provide theoretical guidance for the microcosmic control of clay hydration.

Structural contribution of cationic groups to water sorption in anion exchange membranes: A combined DFT and MD simulation study

Water sorption heavily influences the ionic conduction and dimensional stability of anion exchange membranes (AEMs), however, it is extremely difficult to investigate the structural contributions of different cationic groups to water sorption with only experiments. Here, with the aid of density functional theory (DFT) and molecular dynamics (MD) simulations, such typical structural characteristics as π-conjugated ring and steric hindrance were extracted; and trimethylammonium (QA), 1-methylimidazolium (Im) and tris(2,4,6-trimethoxyphenyl) phosphonium (QP) were investigated as the model cations. It was found that water molecules tend to first fill into the free volume of the AEMs, while the equilibrium water content is the overall result of interchain interactions, cationic hydration, and cationic location in the hydrophilic phase. The interchain interactions (Im > QA > QP) are enhanced by the π-conjugated ring but weakened by the steric hindrance, whereas the cationic hydrations (QA > Im > QP) are reduced by the π-conjugation and steric effects. Accordingly, schematics of the water sorption mechanism and hydrophilic channel morphology are proposed to clarify the impact of cationic structural features on ion conductivity.

Role of cation size on swelling pressure and free energy of mica pores

The ion exchange capacity of clay plays an important role in many industrial applications ranging from radioactive waste disposal to cosmetics. However, swelling or shrinking of clay platelets due to water and ions adsorption in the interstitial zone is also a well-known phenomenon. For their applications, it is crucial to understand the stability of these layered materials, especially after exchange of interstitial ions with surrounding ions having different properties. Here, we probed the role of cation size on swelling pressure and free energy profile. We used molecular simulations to investigate the stability of mica pore, having K+, Rb+, and Cs+ ions. We performed a series of grand canonical Monte Carlo simulations at various pore widths. We probed water adsorption in mica pores from which disjoining pressure, grand potential (swelling free energy), and structural properties of confined water and ions were calculated. While the behavior of these three systems is similar qualitatively because of similar hydration properties of ions, significant differences are observed at the quantitative level due to changes in the hydration structure of cations. The global minimum in swelling free energy is found to be at the smaller pore widths (first minimum) for Rb- and K-mica and at bigger pore widths (second minimum) for Cs-mica pores. We find that ±0.1 Å change in the interstitial cation size leads to a -15 to 5% change in equilibrium loading of adsorbed water and -2 to 35% change in swelling. Our thermodynamic analysis reveals an intricate interplay between enthalpic and entropic contributions caused by the structural change of water in the pores due to the hydration of interstitial cations.

Adsorption of Ca(II) and K(I) on the kaolinite surface: a DFT study with an experimental verification

The clay minerals have a negative influence on the settlement of coal tailings, and the addition of metal cations has a positive effect on treating coal tailings water. Microscopic adsorption mechanism of Ca(II) and K(I) on kaolinite surface was investigated by means of density functional theory (DFT) calculations and Monte Carlo method. The structures of Ca(II) and K(I) adsorption on kaolinite (001) and (00−1) was obtained, with Mulliken bond populations and binding energies calculated. Ca(II) adsorbed on kaolinite (001) surface and K(I) adsorbed on (00−1) surface are their main products, respectively, and the binding energies of all the adsorption products of Ca(II) are higher than those of K(I). Partial density of states projections combining with Mulliken bond charge and populations indicate that Ca−O and K−O bonds of the adsorption products are dominated by ionic interaction. Cation hydration can make the adsorption occurs more easily and enhance the covalent interaction of the bonds. The adsorption experiment verifies that Ca(II) is easier to adsorb on kaolinite than K(I).

Behavior and mechanism of different fraction lead leach with several typical sulfate lixiviants in the weathered crust elution-deposited rare earth ore.

Recently, some new leaching agents without ammonium, such as magnesium sulfate (MgSO4) and aluminum sulfate [Al2(SO4)3], have been developed to eliminate ammonia nitrogen pollution in in situ mining process of the weathered crust elution-deposited rare earth ore (WCED-REO), but they might cause heavy metal contamination. In this study, characteristics and mechanisms of different fractions of lead (Pb) released by (NH4)2SO4, MgSO4 and Al2(SO4)3 leaching agents were investigated using batch experiments and column leaching tests. The experimental results showed that the amounts of Pb released by the different leaching agents followed the trend of Al2(SO4)3 > (NH4)2SO4 > MgSO4 under the same total cationic charge, and both the acid extractable and reducible fractions of Pb were released. The release of acid extractable fraction Pb was related to the cation hydration radius of NH4+, Mg2+, and Al3+, whereas the release of reducible fraction Pb was mainly influenced by the concentration of H+, especially at pH < 4.0. Furthermore, column leaching tests indicated that pH has little effect on the Pb contents of different fractions released by (NH4)2SO4 and MgSO4 in leaching the WCED-REO. Although Al2(SO4)3 released the largest contents of rare earth and Pb in leachate, the content of residual acid extractable fraction Pb in soil was the most after water injection (simulating the cleaning process after mining). This work can provide a scientific method and theoretical basis for comprehensively assessing the environmental impact of new leaching agents on WCED-REO mining.

Study of soil expansion characteristics in rainfall-induced red-bed shallow landslides: Microscopic and macroscopic perspectives.

The main cause of rainfall-induced red-bed shallow landslides is the tendency of red-bed weathered soil to expand when it meets water. However, studies on the expansion mechanism of expansive soil have not considered the effects of hydration and particle orientation. In this study, the hydration force of soil was determined according to the electric double-layer theory, the particle direction of soil was determined by analyzing images of soil obtained by scanning electron microscopy, and, finally, a microscopic model of the electrical double layer of red-bed weathered expansive soil was established in which the hydration force and soil-particle orientation were taken into account. The results showed that the expansion of red-bed weathered expansive soil is the result of hydration forces and repulsive forces in the electric double layer. The grain orientation of the soil strongly influenced the microscopic model. The unloading expansion rate of red-bed weathered expansive soil decreased with an increase in cation concentration and a decrease in pH value. It increased with an increase in the hydration cation radius. These experiments indicate the reliability of the microscopic model and provide a theoretical basis for the prevention and control of rainfall-induced red-bed shallow landslides.

Anionic Tuning of Zeolite Crystallization

Zeolites are of great industrial relevance as catalysts, adsorbents, and ion-exchangers and typically synthesized under hydrothermal conditions. Rational regulation of their crystallization process...

Acid–base reaction of a cationic hydration probe in vicinity of anionic interface of AOT reverse micelles

The excited-state proton transfer (ESPT) of a cationic super-photoacid, N-methyl-7-hydroxyquinolium, has been studied within the water pool of an aerosol-OT reverse micelle (RM). Time-resolved emission spectra were obtained and analyzed to reveal the effect of environmental heterogeneity on the ESPT process. The ESPT was found to involve two main emissive species, namely the excited cationic and keto forms of the photoacid and was facilitated by scenarios that expose them to an abundance of water molecules. The dynamic charge-state transition (from positive to neutral) induced by the ESPT dictated the location and diffusion of the probe with the modulation of the Coulombic interaction between the probe and anionic interface of the RM. The non-exponential behavior of the ESPT was observed using time-resolved intensity profiles and rationalized in terms of the heterogeneity along the reaction coordinates involving the hydrogen-bond network, polarity, and viscosity of the confined water pool within the RM. It was found that the disruption of the hydrogen-bond network in the vicinity of the interface resulted in the decrease of polarity that retarded the overall ESPT by modulating the energetics of the reactant and the product in the ESPT. Solvation dynamics was also considered and found to occur on timescales faster than the ESPT process, profoundly for larger water pools.

Reaction mechanism and dynamics for C8-hydroxylation of 9-methylguanine radical cation by water molecules.

In contrast to their spontaneous deprotonation in aqueous solution, reactions of guanine and guanosine radical cations with water in the gas phase are exclusively initiated by hydration of the radical cations as reported in recent work (Y. Sun et al., Phys. Chem. Chem. Phys., 2018, 20, 27510). As gas-phase hydration reactions closely mimic the actual scenario for guanine radical cations in double-stranded DNA, exploration of subsequent reactions within their water complexes can provide an insight into the resulting oxidative damage to nucleosides. Herein guided-ion beam mass spectrometry experiment and direct dynamics trajectory simulations were carried out to examine prototype complexes of the 9-methylguanine radical cation with one and two water ligands (i.e., 9MG˙+·(H2O)1-2) in the gas phase, wherein the complexes were activated by collisional activation in the experiment and by thermal excitation at high temperatures in the simulations. Guided by mass spectroscopic measurements, trajectory results and reaction potential energy surface, three reaction pathways were identified. The first two reaction pathways start with H-atom abstraction from water by the O6 and N7 atoms in 9MG˙+ and are referred to as HAO6 and HAN7, respectively. The primary products of HAO6 and HAN7 reactions, including [9MG + HO6]+/[9MG + HN7]+ and ˙OH, react further to either form [8OH-9MG + HO6]˙+ and [8OH-9MG + HN7]˙+via C8-hydroxylation or form radical cations of 6-enol-guanine (6-enol-G˙+) and 7H-guanine (7HG˙+) via SN2-type methanol elimination. The third reaction pathway corresponds to the formation of 8OH-9MG+ by H elimination from the complex, referred to as HE. Among these product channels, [8OH-9MG + HN7]˙+ has the most favorable formation probability, especially in the presence of additional water molecules. This product may serve as a preceding structure to the 8-oxo-7,8-dihydroguanine lesion in DNA and has implications for health effects of radiation exposure and radiation therapy.

Isolation sources of micro and macro elements among connection rice samples the creation of drought-resistant forms

Metals content affects not only for nutritional value of plants, but also their resistance to stress. So it was revealed that cationic composition changes hydration of cytoplasm. Hydration of cytoplasm positively correlated with content of alkali metals, a representative of which is potassium, and negatively with amount of alkaline earth metals (calcium, magnesium). Variability of rice collection samples in terms of content of potassium, sodium, calcium, magnesium, ammonium cations has been studied. Sources that are recommended to be used in breeding programs for the creation of drought-resistant forms are highlighted. The potassium content varied in the rice samples from 40 to 90%. In 18 samples, its content did not exceed 70%, in 13 it was above 80%, which makes it possible to recommend them as sources of these trait: Olymp, Ivushka, Dozhdik, Berezka, Rapan, Aurora, Fisht. The study of the relationship between the content of cations showed their presence between the content of potassium and sodium - 0.87, potassium and ammonium - 0.45, calcium and magnesium 0.35.

Pore-Scale Water Vapor Condensation Behaviors in Shales: An Experimental Study

Water condensation in shales impacts its hydro-mechanical response. A mechanistic understanding of the pore-water system is made more challenging by significant anisotropy of pore architecture and nano-scale heterogeneity of pore surfaces. We probe the condensation response in two contrasting shales exposed to a vapor of contrast-matching water, as characterized by in situ ultra-small/small-angle neutron scattering (USANS/SANS) techniques under various relative humidities. One shale with a higher content of both kerogen and clay has rougher surfaces and higher anisotropy than the other shale (less clay and no kerogen) over length scales from 2.5 to 250 nm. Scanning electron microscopy with energy-dispersive spectrometry (SEM–EDS) analysis also confirms that the organic-rich shale presents more anisotropic microfabrics and higher heterogeneity compared to the other shale with less clay and no kerogen. USANS/SANS results show that water condensation effectively narrows the pore volume in the way of reducing the aspect ratio of non-equiaxed pores. For the shale with less clays and no kerogen under a relative humidity of 83%, a wetting film uniformly covers the pore-matrix interface over a wide range of length scale (1 nm–1.9 µm) without smoothing the surface roughness. In contrast, for the organic-rich and clay-rich shale with a strong wetting heterogeneity, condensation occurs at strongly curved hydrophilic asperities (1–10 nm) and smoothens the surface roughness. This is consistent with water vapor condensation behavior in a Vosges sandstone by Broseta et al. (Phys. Rev. Lett. 86:5313, 2001). Though well representing the condensation behavior of water vapor in mesopores/macropores (radii > 1 nm), USANS/SANS techniques could underestimate total water adsorption due to potential cation hydration and clay swelling in micropores (radii < 1 nm).

Fenton reaction mechanism generating no OH radicals in Nafion membrane decomposition

Mechanism of Fenton reaction, which is a most widely-used degradation test for organic materials using hydrogen peroxide (H_2O_2) and iron (Fe) cations, is revealed for the decomposition of hydrated Nafion membrane. This reaction mechanism has been assumed to generate OH radicals. For a doubly-hydrated Nafion membrane model, Fenton reaction with divalent and monovalent Fe (Fe^{2+} and Fe^+) cation hydration complexes is explored for experimentally-supported hydration numbers using long-range correction for density functional theory. As a result, it is found that H_2O_2 coordinating to the Fe^{2+} hydration complexes first approaches Nafion side chains in high humidity, then leads to the C–S bond dissociation of the side chain to produce carbonic acid group and sulfonic acid ion. On the other hand, once electron transfer proceeds between iron ions, the O–O bond of the coordinating H_2O_2 is extended, then the C–S bond is dissociated to produce trihydroxymethyl group and sulfur trioxide, which are rapidly transformed to carboxyl group and sulfonic acid ion in aquo. This mechanism is confirmed by the vibrational spectrum analysis of the decomposed product. Collective Nafion decomposition mechanisms also suggest that the decomposition reaction uses the recycle of generated Fe cation hydration complexes under acidic condition near membrane surface.

Formation of the oxonium phenol ion in the stepwise hydration of the phenyl cation in the gas phase

This study provides the first evidence for the formation of the oxonium phenol ion and its hydrated clusters by the sequential addition of water molecules onto the phenylium ion in the gas phase. The oxonium phenol ion exhibits thermal stability at higher temperatures up to nearly 575 K while the hydrated phenyl cation dissociates by the loss of water at temperatures below 400 K. A second water molecule is attached reversibly to each of the oxonium phenol and the hydrated phenyl ions and equilibrium thermochemical measurements in the low temperature range yield an average −ΔH° of 15.5 kcal/mol reflecting 35% contribution from the hydrated oxonium phenol C6H5OH2+(H2O) and 65% contribution from the second hydration step of the phenyl cation C6H5+(H2O)2. In the high temperature range (373–423 K), the measured average −ΔH° of 18.7 kcal/mol reflects 45% and 55% contributions from the hydrated oxonium phenol and the second hydration step of the phenyl cation, respectively. DFT calculations at the B3LYP/6-311++G** level show that the sequential hydration of the oxonium phenol ion results in the formation of externally hydrated clusters C6H5OH2+(H2O)n where the incoming water molecules form a hydrogen bonding network attached to the oxonium site, and the sequential hydration energy decreases from 25.9 kcal/mol for n = 1 to 11.5 kcal/mol for n = 5. For the hydrated phenyl cation clusters C6H5+(H2O)n, the water molecules are attached at two CHδ+ sites of the phenyl cation, and the sequential hydration energy decreases slowly from 11.3 kcal/mol for n = 1 to 8.1 kcal/mol for n = 5.

Flexible cationic side chains for enhancing the hydroxide ion conductivity of olefinic-type copolymer-based anion exchange membranes: An experimental and theoretical study

The performance of anion exchange membranes (AEMs) is closely related to their cationic groups, hydration degree, and nano-phase morphology. Here, mono- (and di-) quaternary ammonium, pyrrolidinium, and imidazolium cation-based AEMs were synthesized by one-step photo-polymerization. Through combination of experimental and molecular dynamics (MD) approaches, the effects of mono- (and di-) cationic functional groups on the properties of the AEMs, in terms of physicochemical, electrochemical properties, and alkaline stability were comprehensively investigated. It was concluded by the experimental data that AEMs with di-cations exhibit better water uptake, swelling ratio, alkaline stability, and higher ionic conductivity than those with mono-cations. Furthermore, mathematical models of the synthesized AEMs were established for MD simulations, and the calculated radial distribution function and mean square displacements between cationic functional groups, hydroxide ions, and water molecules obtained using the simulated molecular trajectories were examined for the solvation, transport properties, and alkaline stability of AEMs, which are in good qualitative agreement with the experimental results.

Hydration and Diffusion of H+, Li+, Na+, Cs+ Ions in Cation-Exchange Membranes Based on Polyethylene- and Sulfonated-Grafted Polystyrene Studied by NMR Technique and Ionic Conductivity Measurements.

The main particularities of sulfonate groups hydration, water molecule and alkaline metal cation translation mobility as well as ionic conductivity were revealed by NMR and impedance spectroscopy techniques. Cation-exchange membranes MSC based on cross-linked sulfonated polystyrene (PS) grafted on polyethylene with ion-exchange capacity of 2.5 mg-eq/g were investigated. Alkaline metal cation hydration numbers (h) calculated from temperature dependences of 1H chemical shift of water molecule for membranes equilibrated with water vapor at RH = 95% are 5, 6, and 4 for Li+, Na+, and Cs+ ions, respectively. These values are close to h for equimolar aqueous salt solutions. Water molecules and counter ions Li+, Na+, and Cs+ diffusion coefficients were measured by pulsed field gradient NMR on the 1H, 7Li, 23Na, and 133Cs nuclei. For membranes as well as for aqueous chloride solutions, cation diffusion coefficients increased in the following sequence: Li+ < Na+ < Cs+. Cation and water molecule diffusion activation energies in temperature range from 20 °C to 80 °C were close to each other (about 20 kJ/mol). The cation conductivity of MSC membranes is in the same sequence, Li+ < Na+ < Cs+ << H+. The conductivity values calculated from the NMR diffusion coefficients with the use of the Nernst–Einstein equation are essentially higher than experimentally determined coefficients. The reason for this discrepancy is the heterogeneity of membrane pore and channel system. Ionic conductivity is limited by cation transfer in narrow channels, whereas the diffusion coefficient characterizes ion mobility in wide pores first of all.

Understanding the stability mechanism of silica nanoparticles: The effect of cations and EOR chemicals

We have investigated the conditions of colloidal stability of silica nanoparticles smaller than 100 nm for their applications in enhanced oil recovery (EOR), especially pertaining to chemical flooding processes. Using zeta sizer and dynamic light scattering techniques, the stability of silica nanoparticle (SNP) dispersions has been investigated by variation of the pH, composition of salt solutions, addition of surfactants and polyelectrolytes. Such conditions can be encountered in oil reservoirs. It was found that changing pH from 5 to 10 had a negligible effect on the size of SNPs, whereas its zeta potential increased with increasing pH. Aggregation of SNPs is a partially reversible process for low degrees of aggregation in 500 mM NaCl, whereas observed strong aggregation in 1000 mM NaCl was irreversible. A critical aggregation concentration (CAC) was defined for the different salts investigated, above which the SNP dispersion became unstable at a fixed pH of 9.5. The CAC for NaCl was approximately 200 times higher than for CaCl2 and MgCl2. Our observations could not be explained completely by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Therefore, we have included non-DLVO interactions such as cation bridging, hydration forces, and steric effects. The additional presence of anionic alcohol alkoxy sulfate (AAS) surfactant slightly destabilized the SNP solution, but by the addition of polyacrylate (PA) was effectively stabilized. With increasing PA concentration, the CAC for both CaCl2 and MgCl2 increased. Upon addition of 100 ppm PA, the CAC increased by a factor of five compared to the situation in the absence of PA. Reducing the solution pH below 8.5, SNP can be stabilized in higher salinity in the presence of PA. The obtained results contribute to a better fundamental understanding of the SNP stability mechanism and a guide to optimize the SNP injection process with EOR chemicals.

The Influence of Electrolyte Solutions on the Mechanical Properties of Bacterial Cellulose

The mechanical characteristics of bacterial cellulose (one of the most promising cellulose-based nanomaterials) fundamentally depend on its moisture content. It has been found that the effect of aqueous solutions of alkali metal chlorides on its strength and deformation properties is determined by the mobility of water molecules in the near coordination spheres of cation hydration shells.