Bulk Water Phase Research Articles

What causes cardiac mitochondrial failure at high environmental temperatures?

Although a mechanism accounting for hyperthermic death at critical temperatures remains elusive, the mitochondria of crucial active excitable tissues (i.e. heart and brain) may well be key to this process. Mitochondria produce ∼90% of the ATP required by cells to maintain cellular integrity and function. They also integrate into biosynthetic pathways that support metabolism as a whole, allow communication within the cell, and regulate cellular health and death pathways. We have previously shown that cardiac and brain mitochondria demonstrate decreases in the efficiency of, and absolute capacity for ATP synthesis as temperatures rise, until ultimately there is too little ATP to support cellular demands, and organ failure follows. Importantly, substantial decreases in ATP synthesis occur at temperatures immediately below the temperature of heart failure, and this suggests a causal role of mitochondria in hyperthermic death. However, what causes mitochondria to fail? Here, we consider the answers to this question. Mitochondrial dysfunction at high temperature has classically been attributed to elevated leak respiration suspected to result from increased movement of protons (H+) through the inner mitochondrial membrane (IMM), thereby bypassing the ATP synthases. In this Commentary, we introduce some alternative explanations for elevated leak respiration. We first consider respiratory complex I and then propose that a loss of IMM structure occurs as temperatures rise. The loss of the cristae folds of the IMM may affect the efficiency of H+ transport, increasing H+ conductance either through the IMM or into the bulk water phases of mitochondria. In either case, O2 consumption increases while ATP synthesis decreases.

Enhanced Photobiocatalytic Cascades at Pickering Droplet Interfaces.

Developing new methods to engineer photobiocatalytic reactions is of utmost significance for artificial photosynthesis, but it remains a grand challenge due to the intrinsic incompatibility of biocatalysts with photocatalysts. In this work, photocatalysts and enzymes were spatially colocalized at Pickering droplet interfaces, where the reaction microenvironment and the spatial distance between two distinct catalysts were exquisitely regulated to achieve unprecedented photobiocatalytic cascade reactions. As proof of the concept, ultrathin graphitic carbon nitride nanosheets loaded with Au nanoparticles were precisely positioned in the outer interfacial layer of Pickering oil droplets to produce H2O2 under light irradiation, while enzymes were exactly placed in the inner interfacial layer to catalyze the subsequent biocatalytic oxidation reactions using in situ formed H2O2 as an oxidant. In the alkene epoxidation and thioether oxidation, our interfacial photobiocatalytic cascades showed a 2.0-5.8-fold higher overall reaction efficiency than the photobiocatalytic cascades in the bulk water phase. It was demonstrated that spatial localization of the photocatalyst and the enzyme at Pickering oil droplet interfaces not only provided their respective preferable reaction environments and intimate proximity for rapid H2O2 transport but also protected the enzyme from oxidative inactivation caused by the photogenerated species. These remarkable interfacial effects contributed to the significantly enhanced photobiocatalytic cascading efficiency. Our work presents an innovative photobiocatalytic reaction system with manifold benefits, providing a cutting-edge platform for solar-driven chemical transformations via photobiocatalysis.

Gas solubility enhancement and hydrogen bond recombination regulated by terahertz electromagnetic field for rapid formation of gas hydrates

The low solubility of methane in water and the formation of hydrate film at methane-water interface restrict interfacial mass transfer between methane and water, thereby impeding the rapid formation of hydrate. Herein, THz electromagnetic field (TEMF) is introduced to destroy hydrogen bonds through resonance with water molecules for decreasing methane-water interfacial tension (IFT) and improving methane solubility in water. Thereafter, TEMF is removed to restore hydrogen bonding interaction for hydrate nucleation within bulk-phase water rather than at methane-water interface, thereby accelerating hydrate formation. The results show that a TEMF at 15.8 THz can increase methane solubility by 50-fold and provide more nucleation sites for hydrate formation by lowering the IFT by 15-fold. Furthermore, the hydrate nucleation follows “blob” nucleation at low solubility and Local Structuring Mechanism nucleation at high solubility. The higher solubility of methane shortens the induction period of hydrate nucleation form 58.5 ns to 29 ns. Particularly, small 512 cages form preferentially regardless of nucleation pathway. The underlying mechanism for TEMF-induced the acceleration of hydrate formation is attributed to the transition of water phase from a disordered to an ordered structure. This transition arises from the resonance of the TEMF with water molecules, disrupting the hydrogen bond between water molecules and providing sufficient driving force for their rearrangement after removing the TEMF. In rearrangement process, weakly hydrogen-bond interactions correspondingly are converted into strongly hydrogen-bond ones. These findings are expected to improve the understanding of hydrate formation mechanism and promote the applications of terahertz technology in gas hydrates.

Dissolved organic matter isolates obtained by solid phase extraction exhibit higher absorption and lower photo-reactivity: Effect of components

Notable differences in photo-physical and chemical properties were found between bulk water and solid phase extraction (SPE) isolates for dissolved organic matter (DOM). The moieties extracted using modified styrene divinylbenzene cartridges, which predominantly consist of conjugated aromatic molecules like humic acids, contribute mainly to light absorption but exhibit lower quantum yields of fluorescence and photo-produced reactive intermediates (PPRIs). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) revealed lignin as the moieties displaying most significant variance in abundance. In Van Krevelen-Spearman plot, we observed molecules positively or negatively correlated with DOM's optical and photochemical properties (including SUVA254, steady-state concentrations of ·OH, 1O2 quantum yield, etc.) were confined to specific regions, which can be delineated using a threshold modified aromaticity index (AImod) of 0.3. Based on the relationships between optical properties and PPRI production, it is suggested that the energy gap between ground state and excited singlet state (△ES1→S0), governing the inner conversion rate, serves as a determinant for apparent quantum yield of PPRIs in DOM, with intra-molecular charge transfer (CT) interactions potentially playing a pivotal role. Regarding DOM's photoreactivity with pollutants, this study has revealed, for the first time, that protein/amino sugars/amino acids could act as antioxidant groups in addition to phenols on the photolysis of sulfadiazine. These findings provide valuable insights into DOM photochemistry and are expected to stimulate further research in this area.

Utilization of Bubbles and Oil for Microplastic Capture from Water

The removal of microplastics (MPs) from water using oil has shown early promise; however, incorporation of this technique into a feasible in situ method has yet to be developed. Here, a simple yet effective method of MP capture from water using vegetable oil with bubbles is demonstrated to achieve high removal efficiencies of > 98%. Comparisons are made with other methods of agitation, and higher removal efficiencies are observed when bubbles are used. Due to the low agitation provided by the bubbles, the oil layer remains unbroken, meaning that no oil is released into the bulk water phase. In this way, secondary contamination is avoided—unlike membrane filtration, another effective removal method, in which polymer-based membranes can break down due to chemical backwashing and ageing. It is demonstrated that variation in MP size within the micrometer range (50–170 μm) has minor impact on the removal efficiency; however, 100% removal is achieved for larger, millimeter-sized MPs (500–5000 μm). Similarly, a high removal efficiency of greater than 99% is achieved in the capture of microfibers. Other factors such as oil volume and water salinity are also investigated and discussed. Based on these results, the proposed method can be introduced into multiple setting types as a passive and continuous method of MP capture.

Domestic hot-water boilers harbour active thermophilic bacterial communities distinctly different from those in the cold-water supply

Running cold and hot water in buildings is a widely established commodity. However, interests regarding hygiene and microbiological aspects had so far been focussed on cold water. Little attention has been given to the microbiology of domestic hot-water installations (DHWIs), except for aspects of pathogenic Legionella. World-wide, regulations consider hot (or warm) water as ‘heated drinking water’ that must comply (cold) drinking water (DW) standards. However, the few reports that exist indicate presence and growth of microbial flora in DHWIs, even when supplied with water with disinfectant residual. Using flow cytometric (FCM) total cell counting (TCC), FCM-fingerprinting, and 16S rRNA-gene-based metagenomic analysis, the characteristics and composition of bacterial communities in cold drinking water (DW) and hot water from associated boilers (operating at 50 – 60 °C) was studied in 14 selected inhouse DW installations located in Switzerland and Austria. A sampling strategy was applied that ensured access to the bulk water phase of both, supplied cold DW and produced hot boiler water. Generally, 1.3- to 8-fold enhanced TCCs were recorded in hot water compared to those in the supplied cold DW. FCM-fingerprints of cold and corresponding hot water from individual buildings indicated different composition of cold- and hot-water microbial floras. Also, hot waters from each of the boilers sampled had its own individual FCM-fingerprint. 16S rRNA-gene-based metagenomic analysis confirmed the marked differences in composition of microbiomes. E.g., in three neighbouring houses supplied from the same public network pipe each hot-water boiler contained its own thermophilic bacterial flora. Generally, bacterial diversity in cold DW was broad, that in hot water was restricted, with mostly thermophilic strains from the families Hydrogenophilaceae, Nitrosomonadaceae and Thermaceae dominating. Batch growth assays, consisting of cold DW heated up to 50 – 60 °C and inoculated with hot water, resulted in immediate cell growth with doubling times between 5 and 10 h. When cold DW was used as an inoculum no significant growth was observed. Even boilers supplied with UVC-treated cold DW contained an actively growing microbial flora, suggesting such hot-water systems as autonomously operating, thermophilic bioreactors. The generation of assimilable organic carbon from dissolved organic carbon due to heating appears to be the driver for growth of thermophilic microbial communities. Our report suggests that a man-made microbial ecosystem, very close to us all and of potential hygienic importance, may have been overlooked so far. Despite consumers having been exposed to microbial hot-water flora for a long time, with no major pathogens so far been associated specifically with hot-water usage (except for Legionella), the role of harmless thermophiles and their interaction with potential human pathogens able to grow at elevated temperatures in DHWIs remains to be investigated.

Structure of polyethylene glycol/water mixtures as a separation medium of aqueous two-phase extraction systems studied by equilibrium analysis of thiocyanato complexation of Cobalt(II)

Aqueous two-phase systems (ATPS) utilizing polyethylene glycol (PEG) have been successfully used for the separation of various organic and inorganic compounds as an environmentally benign extraction method. However, a fundamental understanding of the role of the hydration structures around PEG chains in solute partitioning in ATPS remains elusive although it has been considered that PEG molecules are involved in separation. In the present work, the equilibria of Co(II) thiocyanate complexation reaction in aqueous PEG solutions were studied by spectrophotometry with varying ethylene oxide chain length and concentration of PEG. From the formation constants of the tetrahedral and octahedral Co(II) thiocyanate complexes obtained, a microheterogeneous structure consisting of pseudo phases formed by hydration of ethylene oxide (EO) chain and terminal hydroxyl (OH) groups in the PEG molecule in addition to the bulk water phase was estimated. It was revealed that the formation of tetrahedral Co(NCS)42− complex proceeds in the EO pseudo phase by the involvement of hydrophobic ethylene groups, while the OH phase and the bulk phase inhibit the progress of the reaction. This indicates that Co(NCS)42− is stable in hydrophobic hydration structure of water around the EO moiety. The EO phase imparts hydrophobicity to aqueous PEG solutions and plays a predominant role in partition of solute molecules in PEG-based ATPS.

A molecular dynamics-based approach to the crystallization of bulk water in the presence of an electric field

The phenomenon of water crystallization is of vital importance for aircraft, warships, transmission lines and daily food preservation. In this paper, the crystalline phase transition of bulk-phase water under the action of an electric field is investigated from a microscopic point of view using molecular dynamics simulations. Based on the melting point and response to electric field, the TIP4P/Ice water molecule model was selected to establish the bulk phase water model, and the effects of the applied electric field in the intensity range of 0.1 V/nm to 30.0 V/nm and different cooling rates on the crystallization of the bulk phase water were investigated. It is found that the water in the system remains in the liquid state under the action of relatively low electric field strengths (0.1 V/nm, 0.2 V/nm, 0.5 V/nm) when the temperature is lowered to 200 K or 100 K. The water in the system is still in the liquid state. Under the action of relatively high electric field strengths (1.0 V/nm-30 V/nm), the hydrogen-bonded network elements are transformed from irregular to ice-phase structure with six-membered rings, which promotes the crystalline phase transition of bulk-phase water. At twice the cooling rate (100 K), the short-range ordering of the system is enhanced at 1.0 V/nm, 5.0 V/nm and 10.0 V/nm electric field strengths.

Template-Directed Replication and Chiral Resolution during Wet-Dry Cycling in Hydrothermal Pools.

The commonly supposed template-based format for RNA self-replication requires both duplex assembly and disassembly. This requisite binary provision presents a challenge to the development of a serviceable self-replication model since chemical reactions are thermochemically unidirectional. We submit that a solution to this problem lies in volcanic landmasses that engage in continuous cycles of wetting and drying and thus uniquely provide the twofold state required for self-replication. Moreover, they offer conditions that initiate chain branching, and thus furnish a path to autocatalytic self-replication. The foundations of this dual thermochemical landscape arise from the broad differences in the properties of the bulk water phase on the one hand, and the air/water interfacial regions that emerge in the evaporative stages on the other. With this reaction system as a basis and employing recognized thermochemical and kinetic parameters, we present simulations displaying the spontaneous and autocatalyzed conversion of racemic and unactivated RNA monomers to necessarily homochiral duplex structures over characteristic periods of years.

How does surfactant aid the displacement of oil by water in nanoscale cracks?

The displacement of oil by water is the central concern in enhanced oil recovery. In this paper, we present an experimental study of the displacement of oil by water in a nano-scale, glass channel. The channel was 100 nm thick, composed of hydrophilic glass, and was closed at one end. Displacement was examined under zero applied pressure. Three surfactants were examined for their ability to aid displacement of oil: sodium dodecylsulfate (SDS), an anionic surfactant; Aerosol OT (AOT), an anionic surfactant; and dodecyltrimethylammonium bromide (DTAB), a cationic surfactant. AOT was the only surfactant that caused displacement of oil within 12 h. AOT is also the only one of the three surfactants that can form reverse micelles in the oil phase, and we attribute the oil displacement to the delivery of water to the hydrophilic glass by reverse micelles. We support this conclusion with experiments showing (a) lesser displacement with fewer reverse micelles and (b) that the water phase is discontinuous. The latter implies transport of water through the oil phase. Therefore, the conclusion of this work is that the surfactant aids oil recovery from a hydrophilic channel by enhancing transport of water through oil. The delivered water can adsorb at the solid and continued transport can spontaneously grow a bulk water phase, thereby displacing the oil.

Improved Methods for Characterizing Emulsions by Low-Resolution Nuclear Magnetic Resonance via Surface Relaxation and One-Dimensional Images

The use of nuclear magnetic resonance (NMR) is an appropriate tool for studying colloids in a non-invasive manner. Droplet size distributions and one-dimensional sample profiles are readily produced to characterize an emulsion, its stability, the size distribution of the dispersed phase, and rheological behavior with respect to parameters as temperature and/or water cut. Here, we present pulsed field Grgdient NMR methods that improve the performance as compared to existing methods. In particular, the so-called multi-echo approach is introduced to enhance the signal-to-noise ratio significantly making it possible to characterize emulsions in a minute or less. Thus, any evolution that takes place in the order of just a few minutes can be monitored. In addition to the multi-echo approach, an improved method for determining the droplet size distribution from a residual emulsion, i.e., in the presence of a bulk water phase, is presented.

Thin sheets of bean curd treated by cold plasma: Changes in surface structure and physicochemical properties

Thin sheets of bean curd (TSBC), a favorite food in China, is mostly vacuum packed to maintain the shelf life. However, the vacuum packing processing will cause adhesion between sheets, which is difficult to peel. To solve this problem, a rapid dehydration technique for the TSBC using cold plasma was developed. The surface structure and physicochemical properties of the TSBC treated by cold plasma were evaluated. The results indicated that water contact angle increased from 0° to 66.37° and 66.94°, and adhesion between sheets decreased from 2.81 g.sec to 0.01 g.sec. It was due to the removal of the bulk-phase water from the TSBC. And scanning electron microscopy showed the formation of a dense structure on the TSBC surface. Moreover, surface structure determination revealed that the cold plasma etching led to the depolymerization of protein and the exposure of hydrophobic points without any effect on the primary structure.

Galvani Offset Potential and Constant-pH Simulations of Membrane Proteins.

A central problem in computational biophysics is the treatment of titratable residues in molecular dynamics simulations of large biological macromolecular systems. Conventional simulation methods ascribe a fixed ionization state to titratable residues in accordance with their pKa and the pH of the system, assuming that an effective average model will be able to capture the predominant behavior of the system. While this assumption may be justifiable in many cases, it is certainly limited, and it is important to design alternative methodologies allowing a more realistic treatment. Constant-pH simulation methods provide powerful approaches to handle titratable residues more realistically by allowing the ionization state to vary statistically during the simulation. Extending the molecular mechanical (MM) potential energy function to a family of potential functions accounting for different ionization states, constant-pH simulations are designed to sample all accessible configurations and ionization states, properly weighted according to their Boltzmann factor. Because protonation and deprotonation events correspond to a change in the total charge, difficulties arise when the long-range Coulomb interaction is treated on the basis of an idealized infinite simulation model and periodic boundary conditions with particle-mesh Ewald lattice sums. Charging free-energy calculations performed under these conditions in aqueous solution depend on the Galvani potential of the bulk water phase. This has important implications for the equilibrium and nonequilibrium constant-pH simulation methods grounded in the relative free-energy difference corresponding to the protonated and unprotonated residues. Here, the effect of the Galvani potential is clarified, and a simple practical solution is introduced to address this issue in constant-pH simulations of the acid-sensing ion channel (ASIC).

Molecular dynamics simulations of cRGD-conjugated PEGylated TiO2 nanoparticles for targeted photodynamic therapy

The conjugation of high-affinity cRGD-containing peptides is a promising approach in nanomedicine to efficiently reduce off-targeting effects and enhance the cellular uptake by integrin-overexpressing tumor cells. Herein we utilize atomistic molecular dynamics simulations to evaluate key structural–functional parameters of these targeting ligands for an effective binding activity towards αVβ3 integrins. An increasing number of cRGD ligands is conjugated to PEG chains grafted to highly curved TiO2 nanoparticles to unveil the impact of cRGD density on the ligand’s presentation, stability, and conformation in an explicit aqueous environment. We find that a low density leads to an optimal spatial presentation of cRGD ligands out of the “stealth” PEGylated layer around the nanosystem, favoring a straight upward orientation and spaced distribution of the targeting ligands in the bulk-water phase. On the contrary, high densities favor over-clustering of cRGD ligands, driven by a concerted mechanism of enhanced ligand–ligand interactions and reduced water accessibility over the ligand’s molecular surface. These findings strongly suggest that the ligand density modulation is a key factor in the design of cRGD-targeting nanodevices to maximize their binding efficiency into over-expressed αVβ3 integrin receptors.

Effect of superheated steam treated wheat flour on quality characteristics and storage stability of fresh noodles

The objective of this study was to enhance the shelf life of fresh noodles prepared by superheated steam (SS) treated wheat flour, and to elucidate the effect of SS treated wheat flour on the quality and storage stability of fresh noodles. SS treated wheat flour improved the initial quality of fresh noodles. Compared with the untreated group, the total plate count (TPC) of SS treated group decreased from 4.10 to 2.87 log10 CFU/g, the L* value increased from 37.98 to 52.00, and the cooking time was significantly shortened from 150 s to 45 s, and the textural properties decreased. SS treatment also improved the storage stability of fresh noodles, prolonged the shelf life to 2 days. During the whole storage period, the TPC of SS treated group was lower than that of the untreated group, and the acidity was significantly reduced. Likewise, the PPO activity and bulk-phase water content were lower, and the water migration was restricted, which inhibited the browning and surface adhesion phenomenon, delaying the deterioration of cooking and textural properties.

Spontaneous generation of stable CO2 emulsions via the dissociation of nanoparticle-aided CO2 hydrate

This study finds that CO2 hydrate dissociation spontaneously generates fine-textured emulsions or foams, and that the phase state of CO2 which was used to form hydrate determines the stability of the emulsion or foam when hydrate is dissociated in an aqueous dispersion of hydrophilic silica nanoparticles. This process suggests an energy-efficient method of generating stable emulsions for high-pressure applications without a need for mechanical energy input. We proved experimentally that the CO2 hydrate phase could be used to generate foams and emulsions because the hydrate formation process naturally disconnects a hydrate guest molecule phase from the bulk water phase. During dissociation, easy adsorption of nanoparticles at CO2-water interfaces hinders the coalescence of bubbles. As a result, CO2 emulsions or foams were generated upon the completion of hydrate dissociation. The CO2 emulsions generated remained fairly stable, while the CO2 foams generated became unstable and the buoyant force of the CO2 bubbles led to their coalescence. The concepts experimentally proven here could be applicable to any suitable clathrate compound undergoing a solid to a liquid phase transition.

Ion-induced oil–water wettability alteration of rock surfaces. Part III: Ion-bridging interactions between oil and solid

We reveal the effects of ions on the oil–water wettability of rock surfaces, which originally adsorb polar molecules via ion-bridging interactions. The ion-induced oil-water wettability alteration is instead revealed by using molecular dynamics simulations, owing to the difficult in the realization of ion-bridging interactions in a hydrated water film in experiments. The results show that the spontaneous displacement of Ca2+ ions in water film by Na+ ions in bulk water phase can weaken the ion-bridging effect and accordingly the rock surface becomes more water-wet. A maximum decrease of approximately 20° in the water contact angle is observed in a period of 30 ns at 0.5 mol/L of Na+ ions. The displacement is guaranteed because smaller Na+ ions can easily embed into silica structure and subsequently weaken the electronegativity of rock surfaces. This study gives a molecular insight of the mechanism of wettability alteration on rock surfaces under ion-bridging interactions.

Polarizable Water Potential Derived from a Model Electron Density.

A new empirical potential for efficient, large scale molecular dynamics simulation of water is presented. The HIPPO (Hydrogen-like Intermolecular Polarizable POtential) force field is based upon the model electron density of a hydrogen-like atom. This framework is used to derive and parametrize individual terms describing charge penetration damped permanent electrostatics, damped polarization, charge transfer, anisotropic Pauli repulsion, and damped dispersion interactions. Initial parameter values were fit to Symmetry Adapted Perturbation Theory (SAPT) energy components for ten water dimer configurations, as well as the radial and angular dependence of the canonical dimer. The SAPT-based parameters were then systematically refined to extend the treatment to water bulk phases. The final HIPPO water model provides a balanced representation of a wide variety of properties of gas phase clusters, liquid water, and ice polymorphs, across a range of temperatures and pressures. This water potential yields a rationalization of water structure, dynamics, and thermodynamics explicitly correlated with an ab initio energy decomposition, while providing a level of accuracy comparable or superior to previous polarizable atomic multipole force fields. The HIPPO water model serves as a cornerstone around which similarly detailed physics-based models can be developed for additional molecular species.

Role of Ferryl Ion Intermediates in Fast Fenton Chemistry on Aqueous Microdroplets.

In the aqueous environment, FeII ions enhance the oxidative potential of ozone and hydrogen peroxide by generating the reactive oxoiron species (ferryl ion, FeIVO2+) and hydroxyl radical (·OH) via Fenton chemistry. Herein, we investigate factors that control the pathways of these reactive intermediates in the oxidation of dimethyl sulfoxide (Me2SO) in FeII solutions reacting with O3 in both bulk-phase water and on the surfaces of aqueous microdroplets. Electrospray ionization mass spectrometry is used to quantify the formation of dimethyl sulfone (Me2SO2, from FeIVO2+ + Me2SO) and methanesulfonate (MeSO3-, from ·OH + Me2SO) over a wide range of FeII and O3 concentrations and pH. In addition, the role of environmentally relevant organic ligands on the reaction kinetics was also explored. The experimental results show that Fenton chemistry proceeds at a rate ∼104 times faster on microdroplets than that in bulk-phase water. Since the production of MeSO3- is initiated by ·OH radicals at diffusion-controlled rates, experimental ratios of Me2SO2/MeSO3- > 102 suggest that FeIVO2+ is the dominant intermediate under all conditions. Me2SO2 yields in the presence of ligands, L, vary as volcano-plot functions of E0(LFeIVO2++ O2/LFe2+ + O3) reduction potentials calculated by DFT with a maximum achieved in the case of L≡oxalate. Our findings underscore the key role of ferryl FeIVO2+ intermediates in Fenton chemistry taking place on aqueous microdroplets.

Energetic Arguments on the Microstructural Analysis in Ionic Liquids

AbstractThe interaction of ionic liquids (ILs) with additives or impurities is crucial for the performance of ILs in technological applications. In order to understand the interaction between these, an insight onto the microscopic arrangement of molecules is needed. As a representative case, 1‐ethyl‐3‐methylimidazolium dicyanamide ([EMIM]+[DCA]−) mixtures are studied with dimethyl sulfoxide (DMSO) and water in bulk phase using molecular dynamics (MD) simulations. Different molar fractions of DMSO and water are studied to elucidate the influence of the molecular solute concentration on the structuring of the ILs. The results indicate that DMSO‐[EMIM]+[DCA] and water‐[EMIM]+[DCA]− mixtures are defined by quite distinct molecular interactions between the species. By increasing the DMSO or water concentration, in the former the solute molecules are repelled from the ions, while in the latter they accumulate closer to the ions. The differences arise from the weakening of the interactions between the ions imposed by the presence of the water molecules whereas DMSO promotes a strengthening of these interactions. Accordingly, this study provides a deep understanding of the IL behavior in combination with neutral solute molecules and allows for a proper selection of IL‐solute combinations in view of specific technological applications.