Anionic Components Research Articles

Structures of LaH10, EuH9, and UH8 superhydrides rationalized by electron counting and Jahn-Teller distortions in a covalent cluster model.

The superconducting hydrides LaH10, EuH9 and UH8 are studied using chemically intuitive bonding analysis of periodic and molecular models. We find trends in the crystallographic and electronic structures of the materials by focusing on chemically meaningful building blocks in the predicted H sublattices. Atomic charge calculations, using two complementary techniques, allow us to assign oxidation states to the metals and divide the H sublattice into neutral and anionic components. Cubic [H8]q- clusters are an important structural motif, and molecular orbital analysis of this cluster in isolation shows the crystal structures to be consistent with our oxidation state assignments. Crystal orbital Hamilton population analysis confirms the applicability of the cluster model to the periodic electronic structure. A Jahn-Teller distortion predicted by MO analysis rationalises the distortion observed in a prior study of EuH9. The impact of this distortion on superconductivity is determined, and implications for crystal structure prediction in other metal-hydrogen systems are discussed. Additionally, the performance of electronic structure analysis methods at high pressures are tested and recommendations for future studies are given. These results demonstrate the value of simple bonding models in rationalizing chemical structures under extreme conditions.

Locality in amino-acid based imidazolium ionic liquids.

Several amino-acid based imidazolium ILs are investigated through the use of ab initio molecular dynamics (AIMD), which includes full polarization. The electric dipole moment distribution and polarization is used as a means of characterizing and understanding these complex systems. Various charge scheme methods were analyzed (Wannier function, Blöchl, Löwdin and Mulliken charge schemes and Voronoi tessellation) to determine their ability to predict dipole moments. These results and the following comparison of methods further deepen the knowledge of polarization by highlighting the importance of the anion and cation separately on polarizability contribution and the need to select a suitable method to predict these. The angular probability distribution is utilized to measure the degree of locality in monopole-dipole electrostatic interactions, which showed no preferential alignment over 700 pm. In addition, the IR and Raman spectra from Voronoi tessellation of [C2C1Im][ala] were analyzed. In these, the strongest signalling peaks showed consistency with experiment and the ability to differentiate between anion and cation components of the IL.

Membrane interaction and selectivity of novel alternating cationic lipid-nanodisc assembling polymers.

Synthetic polymer nanodiscs are self-assembled structures formed from amphipathic copolymers encapsulating membrane proteins and surrounding phospholipids into water soluble discs. These nanostructures have served as an analytical tool for the detergent free solubilisation and structural study of membrane proteins (MPs) in their native lipid environment. We established the polymer-lipid nanodisc forming ability of a novel class of amphipathic copolymer comprised of an alternating sequence of N-alkyl functionalised maleimide (AlkylM) of systematically varied hydrocarbon chain length, and cationic N-methyl-4-vinyl pyridinium iodide (MVP). Using a combination of physicochemical techniques, the solubilisation efficiency, size, structure and shape of DMPC lipid containing poly(MVP-co-AlkylM) nanodiscs were determined. Lipid solubilisation increased with AlkylM hydrocarbon chain length from methyl (MM), ethyl (EtM), n-propyl (PM), iso-butyl (IBM) through to n-butyl (BM) maleimide bearing polymers. More hydrophobic derivatives formed smaller sized nanodiscs and lipid ordering within poly(MVP-co-AlkylM) nanodiscs was affected by nanodisc size. In dye-release assays, shorter N-alkyl substituted polymers, particularly poly(MVP-co-EtM), exhibited low activities against eukaryotic mimetic POPC membrane and increased their liposome disruption as POPC : POPG membrane mixtures increased in their anionic POPG component, resembling the charge profile of bacterial membranes. These trends in membrane selectivity were transferred towards native cell systems in which gram-positive Staphylococcus aureus and gram-negative Acenobacter baumannii bacterial strains were relatively susceptible to disruption by hydrophobic n-butyl- and n-propyl-poly(MVP-co-AlkylM) derivatives compared to human red blood cells (HRBCs), with a more pronounced selectivity resulting from poly(MVP-co-PM). Such selective membrane interaction by less hydrophobic polymers provides a framework for polymer design towards applications including selective membrane component solubilisation, biosensing and antimicrobial development.

An inhibitory mechanism for suppressing high salt intake in Drosophila.

High concentrations of dietary salt are harmful to health. Like most animals, Drosophila melanogaster are attracted to foods that have low concentrations of salt, but show strong taste avoidance of high salt foods. Salt in known on multiple classes of taste neurons, activating Gr64f sweet-sensing neurons that drive food acceptance and 2 others (Gr66a bitter and Ppk23 high salt) that drive food rejection. Here we find that NaCl elicits a bimodal dose-dependent response in Gr64f taste neurons, which show high activity with low salt and depressed activity with high salt. High salt also inhibits the sugar response of Gr64f neurons, and this action is independent of the neuron's taste response to salt. Consistent with the electrophysiological analysis, feeding suppression in the presence of salt correlates with inhibition of Gr64f neuron activity, and remains if high salt taste neurons are genetically silenced. Other salts such as Na2SO4, KCl, MgSO4, CaCl2, and FeCl3 act on sugar response and feeding behavior in the same way. A comparison of the effects of various salts suggests that inhibition is dictated by the cationic moiety rather than the anionic component of the salt. Notably, high salt-dependent inhibition is not observed in Gr66a neurons-response to a canonical bitter tastant, denatonium, is not altered by high salt. Overall, this study characterizes a mechanism in appetitive Gr64f neurons that can deter ingestion of potentially harmful salts.

Salinity and Heavy Metal Tolerance, and Phytoextraction Potential of Ranunculus sceleratus Plants from a Sandy Coastal Beach.

The aim of the present study was to evaluate tolerance to salinity and different heavy metals as well as the phytoextraction potential of Ranunculus sceleratus plants from a brackish coastal sandy beach habitat. Four separate experiments were performed with R. sceleratus plants in controlled conditions: (1) the effect of NaCl gradient on growth and ion accumulation, (2) the effect of different Na+ and K+ salts on growth and ion accumulation, (3) heavy metal tolerance and metal accumulation potential, (4) the effect of different forms of Pb salts (nitrate and acetate) on plant growth and Pb accumulation. A negative effect of NaCl on plant biomass was evident at 0.5 g L-1 Na+ and growth was inhibited by 44% at 10 g L-1 Na+, and this was associated with changes in biomass allocation. The maximum Na+ accumulation (90.8 g kg-1) was found in the stems of plants treated with 10 g kg-1 Na+. The type of anion determined the salinity tolerance of R. sceleratus plants, as Na+ and K+ salts with an identical anion component had a comparable effect on plant growth: nitrates strongly stimulated plant growth, and chloride treatment resulted in slight but significant growth reduction, but plants treated with nitrites and carbonates died within 4 and 5 weeks after the full treatment, respectively. The shoot growth of R. sceleratus plants was relatively insensitive to treatment with Mn, Cd and Zn in the form of sulphate salts, but Pb nitrate increased it. Hyperaccumulation threshold concentration values in the leaves of R. sceleratus were reached for Cd, Pb and Zn. R. sceleratus can be characterized as a shoot accumulator of heavy metals and a hyperaccumulator of Na+. A relatively short life cycle together with a high biomass accumulation rate makes R. sceleratus useful for dynamic constructed wetland systems aiming for the purification of concentrated wastewaters.

PH-Driven Selective Adsorption of Multi-Dyes Solutions by Loofah Sponge and Polyaniline-Modified Loofah Sponge.

In the last decades, sorbent materials characterized by low selectivity have been developed for the removal of pollutants (in particular dyes) from wastewater. However, following the circular economy perspective, the possibility to selectively adsorb and desorb dyes molecules today represents an unavoidable challenge deserving to be faced. Herein, we propose a sequential treatment based on the use of PANI-modified loofah (P-LS) and loofah sponge (LS) to selectively adsorb cationic (rhodamine, RHB, and methylene blue, MB) and anionic (methyl orange, MO) dyes mixed in aqueous solution by tuning the adsorption pH (100% MO removal by P-LS and 100% and 70% abatement of MB and RHB, respectively, by LS). The system maintained high sorption activity for five consecutive cycles. A simple and effective regeneration procedure for the spent adsorbents permits the recovery of the initial sorption capability of the materials (81% for MO, ca. 85% for both RHB and MB, respectively) and, at the same time, the selective release of most of the adsorbed cationic dyes (50% of the adsorbed MB and 50% of the adsorbed RHB), although the procedure failed regarding the release of the anionic component. This approach paved the way to overcome the traditional procedure based on an indiscriminate removal/degradation of pollutants, making the industrial wastewater a potential source of useful chemicals.

Compositional characterisation of papadkhar and deciphering the influence of cationic and anionic component(s) of salt on the quality attributes of papads

SummaryPapadkhar, an efflorescent ash, is an essential ingredient in papad manufacturing which enhances texture. This study is comprised of two parts: Initially, papadkhar samples were collected from various regions of India and evaluated for physicochemical parameters and heavy metals. Cadmium (<2.29 mass%), mercury (<2.48 mass%) and lead (<32.38 mass%) were detected. However, the regulations for heavy metal contamination in papadkhar are inexplicit. The study suggested the need to evaluate toxicity and regulate heavy metal contamination below the threshold value. Optimal papadkhar concentration was found to be 3% (w/w). Furthermore, literature emphasising the role of salt components on papad quality is scanty. The second part of the study focused on deciphering the role of cationic and anionic salt component(s) on physicochemical properties of papads. To study the effect of cations, varying levels (0.5%–1.5%) of sodium, calcium, magnesium and potassium carbonates were used. Sodium salts were chosen for further studies considering lower dough hardness (136.3–123.0 g). Hereinafter, sodium salt of sulphate, phosphate, chloride and carbonate (0.5%–1.5%) were selected. A blend of 3:1 ratio of sodium carbonate and sodium bicarbonate at 1% (w/w) showed the best organoleptic acceptability.

Influence of wastewater matrix on the visible light degradation of phenol using AgCl/Bi24O31Cl10 photocatalyst.

A significant amount of research has been conducted on the development and application of photocatalytic materials for the visible light degradation of organic pollutants in wastewater. However, most pollutant degradation studies are conducted using simulated wastewater often prepared using DI water. This is far removed from the realities of environmentally relevant water systems. It is therefore important to investigate the activity of these semiconductor materials with real water samples. In this study, the photocatalytic activity of the photocatalyst was investigated in the secondary effluent of a wastewater treatment plant (WWTP) in Pretoria, South Africa, for the degradation of phenol under visible light irradiation. The experimental design was done using the Taguchi method L16 orthogonal tray with three factors (pH, initial phenol concentration, and photocatalyst dosage) and four levels. The results show that pH is the highest-ranked significant factor influencing the degradation rate, closely followed by the initial concentration of the pollutant. The photocatalyst dosage had the least significant impact on degradation. The effects of individual anion components such as Cl-, NO3-, NO2-, SO42- and cations such as Ca2+, Mg2+, Zn2+, and K+ were investigated. While Cl- did not negatively influence the degradation rate, the results show that NO3- and SO42- inhibit the degradation of phenol. More specifically, the presence of nitrites resulted in total impeding of the degradation process illustrating that nitrite concentrations ≥ 20ppm should be removed from wastewater prior to photocatalytic degradation. The cations investigated promoted the degradation of phenol. Generally, there was enhanced degradation in the water matrix when compared to DI water, and the results revealed improved degradation efficiency due to the cumulative impact of various components of the wastewater.

Influence of brine compositions on wetting preference of montmorillonite in rock/brine/oil system: An in silico study

In this paper, we investigated dependency of thin brine film stability confined between rock and hydrocarbon layer on brine solution properties in terms of salinity and anionic components. Molecular Dynamics simulation was used to investigate behavior of the system at rock/brine and brine/oil interfaces to characterize thin brine film. Here, montmorillonite, a thin water film containing different salinities (low salinity water, 5,000 ppm, and high salinity water, 70,000 ppm) of NaCl and Na2SO4, and organic components constituting 3:1 M mixture of decane and sodium decanoate were considered to represent rock, brine, and oil, respectively. High salinity brine makes the thin film more stable. Extensive repulsive electrostatic forces between Cl− anions distributed in brine film and carboxylate functional groups at the brine/oil interface impede penetration of oil components into the brine film and then their adsorption onto the clay surface. Low salinity Na2SO4 showed the most stable brine film, in which distribution of anions at the brine/oil interface prevents intrusion of oil components into the brine film. However, high salinity Na2SO4 showed strong potential in forming ionic aggregations comprising Na+ cations and anions. These ionic aggregations act as bridging agents to adhere oil constituents onto the clay slab.

Enhancing performance of organic-inorganic perovskite solar cells using super halogen additive

Compositional engineering in perovskite solar cells usually uses mixed cations and halide anions to optimize the growth of perovskite films, reduce film defects and inhibit carrier recombination to achieve high-performance devices. The most commonly used anion component of perovskite is the iodine ion. However, the ionic behavior of iodine greatly affects the stability of perovskite solar cell devices. Here, NaBF 4 was first used to partially replace iodine in perovskite CS 0.05 (FA 0.92 MA 0.08 ) 0.95 Pb(I 0.92 Br 0.08 ) 3 . After doping NaBF 4 , perovskite films show a longer PL lifetime and greater recombination resistance. It is found that the Stokes shift of the PL peak of the target film is reduced, indicating that doping NaBF 4 significantly inhibits the non-radiative recombination in the perovskite film. Doping NaBF 4 in perovskite passivates its defects, significantly improves the open-circuit voltage, filling factor and the power conversion efficiency of the device from 18.31% of the original device to 20.63%. After being stored in a nitrogen environment for 2400 hours, the device efficiency remains unchanged. • A super halogen BF 4 − anion is used to partially replace iodine ion to fine tune the perovskite components. • The efficiency of perovskite solar cell is increased from 18.31% to 20.63%. • After being stored in a nitrogen environment for 2400 hours, the device efficiency remains unchanged.

Anion-induced morphology control of Al-fumarate MOFs via synergetic coordination and hydrogen bond effects for graded dehumidification

Metal organic framework (MOF) dehumidifier presents vast application value to alleviate the humidity stress to improve the comfort of humans. Aluminum-fumarate based MOFs (AF-MOFs) are expected as an important class in this field since their flexibility allows the water adsorption properties to be tunable from the molecular level of the inorganic node and/or organic linkers. Here, AF-MOFs samples were prepared using aluminum salts containing different anions (SO42−, Cl−, NO3−) to reveal how the anion components affect their morphology and thereby disclose the relationship between their structures and activities of water absorption. Systematic characterizations demonstrated that the anions achieved fine morphology control of AF-MOF samples without changing their basic framework, wherein the coordination effect between aluminum atoms in MOF units and atoms in anions (such as oxygen and nitrogen) induced this process. What's more, the water adsorption experiments revealed that by means of the collaborative assistance of specific surface area, hydrogen bond interaction and/or coordination effects, the SO42−, Cl− and NO3− induced AF-MOFs reveal optimal water absorption performance at low, medium and high relative pressure, respectively. With no complex steps, extra morphology modulators and harsh temperature/pressure, this study provides an environmentally friendly new sight for regulating the morphology of AF-MOFs to optimize their dehumidification abilities.

Filtering the NMR Spectra of Mixtures by Coordination to Paramagnetic Cu2.

The paramagnetic spin relaxation (PSR) filter allows the selective NMR signal suppression of components in mixtures according to their complexation ability to a paramagnetic ion. It relies on the faster relaxation of nuclei in paramagnetic environments and thus is complementary to classical diffusion and relaxation filters. So far, the PSR filter has established Gd3+ as the sole PSR agent, restricting the paramagnetic filtering repertoire. Herein, we present Cu2+ as a robust PSR agent with characteristic filtering properties. While Gd3+ depends on unspecific ion-pair interactions with anionic components, Cu2+ stands out for filtering species via ordered coordination complexes. An evaluation of the paramagnetic effect of Cu2+ over more than 50 small molecules and polymers has unveiled different sensitivities to Cu2+ (especially high for pyridines, diamines, polyamines, and amino alcohols) and precise filtering conditions for mixtures (1H, COSY, and HMQC) that were challenged with a test bed of commercial drugs. The advantage of integrating Cu2+ and Gd3+ for the stepwise PSR filtering of complex mixtures is also shown.

Micro-Environment mapping of mole fraction inspired contrasting charged aqueous gemini micelles: A drug solubilization/release study

Data on aggregation/morphological behaviour of contrasting charge aqueous gemini mixtures at 303 K have been acquired in this study. Anionic and cationic components of the mixture were phosphoric acid, P, P' −1,4-butanedieyl, P, P' didodecylester, disodium salt (12–4-12A) and (ethane-1,2-diyl bis (N, N-dimethyl-N-alkylammoniumacetoamide) dichloride) (12-Eda-12 or 14-Eda-14), respectively. Fluorescence data are used to acquire critical micelle concentration (CMC) value and micro-environmental information (micro-polarity and dielectric constant). DLS, SANS and TEM confirm the presence of ellipsoidal, rod-shaped or vesicles at different compositions of the mixture(s). Further, zeta-potential (ζ) data reveal the charge reversal on the aggregate by mole fraction (x) variation (0–1) of the mixture. Solubilization of an anti-cancer drug (raloxifene hydrochloride, RLX) has been seen in various morphologies (spectrophotometrically) and it has been found that vesicles (formed at x = 0.4 or 0.6) solubilize more RLX than the any other morphology. RLX release profile follows Higuchi model which confirms the diffusional release mechanism. RLX solubilised in 12–4-12A + 14-Eda-14 mixture (x = 0.6 and x = 0.4, respectively) showed good cell proliferation behaviour (9.06 µg/mL) over pure RLX (21.75 µg/mL) towards MCF-7.

Highly efficient and stable red-emitting Sb-doped Indium-based perovskites via anionic component engineering

Indium (In)-based perovskites have become promising benign alternatives of lead halide perovskites due to their considerable stability, less toxicity and highly luminescence efficiency. Herein, the highly efficient and stable red-emitting Sb-doped In-based perovskites were synthesized via anionic component engineering. The as-synthesized Sb:Cs2InClBr4·H2O crystals gave a wide emission band at 680 nm from self-trapped excitons with an extraordinary high photoluminescence quantum yield of 93% due to the modified charge-transfer energy and distorted lattice enhanced electron-phonon coupling by Br- ions incorporation. In addition, the Sb:Cs2InClBr4·H2O crystals also exhibited excellent thermal stability, which could facilitate their applications. In addition, a cool white light-emitting diode with high brightness was manufactured by using this product, with some other luminescent QDs. These results demonstrate the applicability and processibility of anionic component engineering in the synthesis of highly efficient and tunable emitting In-based perovskites, which would promote their application in optoelectronic devices.

Column leaching of ion adsorption rare earth ore at low ammonium concentration

Ammonium sulfate ((NH4)2SO4) is currently the most commonly used leaching agent for the extraction of ion adsorption rare earth ore (IARE-ore) in industrial production. However, ammonium sulfate technology has been gradually restricted to use mainly due to its environmental damage, thus resulting in serious challenges in the IARE-ore industry. Based on the leaching mechanism of cation exchange, a high ammonium concentration is required in ammonium sulfate leaching. In addition, the anion of sulfate radicals has almost no ability to leach rare earth elements (REEs), which are also a component of environmental pollution. Therefore, it is important to reduce the concentration of the leaching agent, especially the ammonium concentration in the IARE-ore leaching process. In this work, ammonium citrate was used as a new leaching agent in IARE-ore leaching. The column leaching results showed that high REEs recovery can be obtained at relatively low ammonium concentration. Both of the cation and anion components of ammonium citrate were effective in the REEs leaching process, thus resulting in cooperative effects. A liquid/solid ratio of 4:1 and a pH of 6 were the appropriate conditions for the extraction of rare earth with ammonium citrate, while the appropriate pH for ammonium sulfate was 2. This work provides a new approach to solving the challenge of traditional ammonium technology by designing and changing the molecular structure of ammonium leaching agents.

Ionic liquid-mediated reconstruction of perovskite surface for highly efficient photovoltaics

To achieve efficient harvesting of light energy, perovskite photovoltaics require a surface passivation process of the perovskite layer. In this study, 1-butylmethylimidazolium hexafluorophosphate ionic liquid was adopted as a surface modifier to passivate a perovskite layer through post-treatment. Results revealed that the ionic liquid effectively reduces surface traps by inducing simultaneous interactions from both cation and anion components. Consequently, the surface treatment with the ionic liquid provided a ∼ 15% improvement in the efficiency of the perovskite photovoltaics. However, the formation of perovskite–ionic liquid complex, leading to inefficient charge transport and extraction, was observed when an excess amount of the ionic liquid was used owing to the penetration of the ionic liquid into the photo-active layer. These observations suggest that the ionic liquid should be selectively exposed to the perovskite surface to optimize the efficiency of perovskite photovoltaics treated with ionic liquids.

Fluoride Ion-Encapsulated Germoxane Cages Modified with Organosiloxane Chains as Anionic Components of Ionic Liquids

Fluoride Ion-Encapsulated Germoxane Cages Modified with Organosiloxane Chains as Anionic Components of Ionic Liquids

The Novel Polymethacrylate Based Hydrophilic Stationary Phase for Ion Chromatography.

Ion chromatography is widely used as a useful and powerful tool for the analysis of anionic and cationic components found in waters and aqueous media. The performance and selectivity of ion chromatography are based on the stationary phase column packed material. In this study, it is aimed to develop new column material with quaternary ammonium functional group based on monodisperse polymeric particles for ion chromatography and to investigate their chromatographic performance. For the analysis of inorganic anions by ion chromatography, new stationary phases macroporous monodisperse particles based on 3-chloro-2-hydroxy propylmethacrylate-co-ethylene dimethacrylate are obtained as column packing material. 3-chloro-2-hydroxy propylmethacrylate and ethylene glycol dimethacrylate are transformed to porous monodisperse particle form by using glycidyl methacrylate as the seed latex and ethyl benzene as the porogen solvent via micro-suspension polymerization technique. Then macroporous monodisperse particles surface is functionalized by triethylamine so strong anion exchange is obtained for ion chromatography packing material. A series of stationary phases prepared from polymer particles containing different amounts of porogen solvent were tested. The results show that column packing material is successful to separate inorganic anions mixture such as F-, Cl-, NO2-, Br-, NO3- by using the carbonate and bicarbonate solutions as mobile phases.

Symmetry between Structure–Antibacterial Effect of Polymers Functionalized with Phosphonium Salts

In actual context, when the terms of biomass and bioenergy are extensively used, it becomes clear that the comparative study of some biopolymers, such as cellulose and chitosan, can offer a large usage range, based on the scientific progress obtained in the biomaterials field. Starting from the structural similarity of these two polymers, we synthesized composite materials by grafting on their surface biocide substances (phosphonium salts). After testing the biocidal effect, we can conclude that the antibacterial effect depends on the ratio of support to phosphonium salt, influenced by the interaction between the cationic component of the biocides and by the anionic component of the bacterial cellular membrane. It was also observed that for the materials obtained by cellulose functionalization with tri-n-butyl-hexadecyl phosphonium bromide, the bacterial effect on E. coli strain was much better when chitosan was used as the support material.

Atomistic insights into role of low salinity water on montmorillonite-brine interface: Implications for EOR from clay-bearing sandstone reservoirs

Low salinity waterflooding (LSWF) is considered as a potentially promising approach to improve oil production from petroleum reservoirs. Nevertheless, ambiguities about dominant mechanisms and influential factors controlling the wettability alteration on rock surface still remain elusive. To date, the main attention has been given to securitizing the impact of salinity, oil composition, rock surface characteristics, and cationic part of the brine, largely overlooking the impact of anionic components of the brine. However, this is of great importance and interest to clarify how the anionic component of salt can contribute to rock-brine interface characteristics. In this paper, we used Molecular Dynamics (MD) simulation technique to characterize the effect of anionic components of brine solution on intermolecular interactions at the montmorillonite-brine interface. Here, the emphasis was put on NaCl and Na2SO4 brine solution to compare the ionic behavior of Cl- and SO42- in terms of distribution adjacent to the clay surface, potential for ionic aggregation formation, and pairwise interactions over a salinity range of 2000 ppm to 70000 ppm. Results obtained from this research work show that anionic SO42- accumulate nearby the clay surface in the form of ionic aggregations with Na+ cations, compared to the Cl- anions, which are uniformly distribute over the clay surface. The strong propensity of SO42- towards Na+ reduces the possibility of hydration by water molecules, disintegrating the bridging role of Na+ to adsorb oil constituents onto the clay surface. Furthermore, the disparate adsorption of SO42--Na+ aggregation onto the clay slab hinders oil diffusion toward the surface. Finally, besides salinity, anionic components of brine solution have no effect on expansion of the electrical double layer (EDL), casting a shadow on this phenomenon as a driving factor of LSWI-EOR. The results obtained from this research work can further our understanding of clay-brine interaction which is a major mechanism behind low salinity effect in clay-bearing petroleum reservoirs.