Liquid-liquid Interaction Research Articles

Therapeutic targeting of FUBP3 phase separation by GATA2-AS1 inhibits malate-aspartate shuttle and neuroblastoma progression via modulating SUZ12 activity.

Malate-aspartate shuttle (MAS) is essential for maintaining glycolysis and energy metabolism in tumors, while its regulatory mechanisms in neuroblastoma (NB), the commonest extracranial malignancy during childhood, still remain to be elucidated. Herein, by analyzing multi-omics data, GATA binding protein 2 (GATA2) and its antisense RNA 1 (GATA2-AS1) were identified to suppress MAS during NB progression. Mechanistic studies revealed that GATA2 inhibited the transcription of glutamic-oxaloacetic transaminase 2 (GOT2) and malate dehydrogenase 2 (MDH2). As a long non-coding RNA destabilized by RNA binding motif protein 15-mediated N6-methyladenosine methylation, GATA2-AS1 bound with far upstream element binding protein 3 (FUBP3) to repress its liquid-liquid phase separation and interaction with suppressor of zest 12 (SUZ12), resulting in decrease of SUZ12 activity and epigenetic up-regulation of GATA2 and other tumor suppressors. Rescue experiments revealed that GATA2-AS1 inhibited MAS and NB progression via repressing interaction between FUBP3 and SUZ12. Pre-clinically, administration of lentivirus carrying GATA2-AS1 suppressed MAS, aerobic glycolysis, and aggressive behaviors of NB xenografts. Notably, low GATA2-AS1 or GATA2 expression and high FUBP3, SUZ12, GOT2 or MDH2 levels were linked with unfavorable outcome of NB patients. These findings suggest that GATA2-AS1 inhibits FUBP3 phase separation to repress MAS and NB progression via modulating SUZ12 activity.

On chip microfluidic separation of cyclotides.

Cyclotides as a cyclic peptide produced by different groups of plants have been a very attractive field of research due to their exceptional properties in biological activities and drug design applications. The importance of cyclotides as new biological activities from nature caused to attract researchers to develop new separation systems. Recent growth and development on chip-based technology for separation and bioassay especially for anticancer having sparklingly advantages comparison with common traditional methods. In this study, the microfluidic separation of Vigno 1-5 cyclotides extracted from Viola ignobilis by using polar and nonpolar forces as a liquid-liquid interaction was investigated through modified microfluidic chips and then the results were compared with a traditional counterpart technique of high-performance liquid chromatography (HPLC). The traditional process of separating cyclotides from plants is a costly and time-consuming procedure. The scientific novelty of this study is to accelerate the separation of cyclotides using modified microfluidic chips with low cost and high efficiency. The results revealed that a novel and simple microfluidic chip concept is an effective approach for separating the Vigno groups in the violet extract. We believe that the concept could potentially be utilized for further drug development process especially for anticancer studies by coupling bioassay chips as online procedures via reducing in time and cost compared with traditional offline methods.

Wetting-Induced Water Promoted Flow on Tunable Liquid-Liquid Interface-Based Nanopore Membrane System.

Membrane separation provides effective methods for solving the global water crisis. Contemporary membrane systems depend on interfacial interactions between liquid and solid membrane matrixes. However, it may lead to a limiting permeate flux due to the large flow resistance at hydrophobic liquid-solid interfaces. Herein, the liquid-liquid interface with improved interface energy is reversibly introduced in membrane systems to boost wetting and reduce transport resistance. A series of interfaces were systematically explored to reveal mechanisms of wetting and boosted flow performances, which are further supported by simulations. Findings of this study highlight that interfacial liquids with lower surface energies, lower viscosities, and higher solubilities can effectively improve water flow without sacrificing rejection performance, achieving by transforming a solid-liquid interface into liquid-liquid interface interaction. It provides a concept to design advanced membrane systems for water purification (e.g., desalination and oil-water separation) and energy conversion processes.

Exploration of liquid-liquid equilibrium and interaction between guaiacol and water extracted by four ester solvents

Four ester solvents were selected as extractants and compared to explore the separation process of recovering guaiacol from an aqueous solution. The liquid-liquid equilibrium (LLE) data for water + guaiacol+ {methyl acetate, ethyl acetate, n-propyl acetate or n-butyl acetate} were measured in 303.2 K and 101.3 kPa. The separate performance in the four extractants was compared and evaluated by the distribution coefficient (D) and the separation factor (S). The NRTL and UNIQUAC models were correlated and fitted to experimental data to obtain regression parameters. Furthermore, the hybrid surface analysis based on Gibbs energy topology verified that the binary interaction parameters are consistent with the measured data. The root mean square deviation (RMSD) of the NRTL and UNIQUAC model does not exceed 0.0076 and 0.0086, respectively, indicating that the above models are suitable for studying the correlation of the system. In addition, the interaction and interaction energy between component molecules were studied through the DMol3 module.

Liquid-liquid phase equilibrium and interaction exploration for separation 2-methoxy-phenol and water with different solvents

To recover 2-methoxy-phenol in water, C5-C8 alkyl alcohols were selected as extractants to separate water and 2-methoxy-phenol. The liquid–liquid equilibrium (LLE) data for water + 2-methoxy-phenol + {1-pentanol, 1-hexanol, 1-heptanol or 1-octanol} were explored in 303.2 K under 101.3 kPa. The extraction performance of four extractants was assessed through the distribution coefficient (D) and separation factor (S). Meanwhile, the NRTL and UNIQUAC models were used to correlate and fit the data to obtain regression parameters. Furthermore, the mixed surface analysis based on Gibbs energy topology verified that the binary interaction parameters are consistent with the measured data. The LLE data were also predicted through the COSMO-UNIFAC model. The root mean square deviation (RMSD) of the three models do not exceed 0.0023, 0.0030, and 0.0234, respectively, indicating that the NRTL and UNIQUAC models are suitable for the correlation of the studied system and the COSMO-UNIFAC model can be the way to predict the LLE data of the researched system within the scope of this work. In addition, the interaction and interaction energy between component molecules were studied through the DMol3 module.

Liquid-liquid equilibrium measurements and interaction explorations for separation of azeotrope n-butyl acetate and n-butanol using three ionic liquids

To separate the azeotropic mixture n-butyl acetate and n-butanol by liquid–liquid extraction, three ionic liquids (ILs) 1-ethyl-3-methylimidazolium dihydrogen phosphate ([Emim]H2PO4), 1-butyl-3-methylimidazolium dihydrogen phosphate ([Bmim]H2PO4) and 1-hexyl-3-methylimidazolium dihydrogen phosphate ([Hmim]H2PO4) were adopted as extractants. The liquid–liquid equilibrium data for the ternary mixtures (n-butyl acetate + n-butanol + [Emim]H2PO4/[Bmim]H2PO4/[Hmim]H2PO4) was measured at 298.15 K and 101.3 kPa. The extraction capacity of the ionic liquids was evaluated by partition coefficient and selectivity. The NRTL model was applied to fit the measured data with the root mean square deviation less than 0.009. The hydrogen bond length and interaction energy between the ionic liquids and n-butyl acetate/n-butanol was calculated and the effect of the ionic liquid cations with different carbon chain length was explored.

Extraction of {benzene, toluene, thiophene and 3-methylthiophene} from n-hexane: Liquid-liquid equilibrium measurements and interaction exploration

In order to investigate the ability of N-methyl-2-pyrrolidone (NMP) to extract aromatics (benzene, toluene) and sulfides (3-methylthiophene, thiophene) from n-hexane, the liquid-liquid equilibrium (LLE) data of n-hexane + {benzene, toluene, thiophene or 3-methylthiophene} + NMP systems were determined at 293.15 K under 101.3 kPa. The Othmer-Tobias and Hand equations were applied to validate the reliability of the obtained LLE data, and the correlation coefficients (R2) are close to unity. It was found that sulfides could be successfully extracted from n-hexane by NMP solvent companying with the extraction of aromatics. However, the separation factors and distribution coefficients of the sulfides are greater than those of aromatics, indicating that the sulfides are more easily extracted by NMP. Furthermore, the separation energies of the sulfides are greater than that of aromatics, which is also a piece of evidence for easier separation of sulfides. In order to extend those results to other extraction processes involving those sulfides, aromatics and solvent, the binary interaction parameters of the NRTL and UNIQUAC thermodynamic models were calculated by correlating the LLE data. The RMSD values were all <0.0070, and a graphical user interface based on the Gibbs tangent plane test was also applied to validate the coherent consistency of the parameters. The results show that the obtained binary interaction parameters could be reliable adopted in the design and optimization of the related extraction/separation process in industry.

Molecular Dynamics Study of Binary Nanodroplet Evaporation on a Heated Homogeneous Substrate.

The evaporation mechanism of miscible binary nanodroplets from heated homogeneous surfaces was studied by molecular dynamics simulations, which has never been studied before. The binary droplets contain a hydrophilic component (type-2 particles) and a hydrophobic component (type-3 particles). It is shown that liquid-liquid interaction strength (ε23) and hydrophilic particle number fraction (φ) have great influence on the surface tension, wetting characteristics, evaporation patterns, evaporation rate, and local mass flux. It is observed that when ε23 ≥ 1, or φ ≈ 0.5, the evaporation mode is the constant-contact-angle mode. Otherwise, it is the mixed mode. We found that the evaporation rate becomes faster when φ and ε23 increase. The droplets become more hydrophilic when φ increases, which promotes heat transfer efficiency between the liquid-solid interface. Besides, a larger ε23 promotes the heat transfer inside the droplet. The mass transfer to the vapor phase occurs preferentially in the vicinity of TPCL (three phase contact line) in the hydrophilic systems (θ < θc), where θc is the critical contact angle, while in most hydrophobic systems (θ > θc), the mass flux close to the TPCL is suppressed. We found that θc ∈ (102°-106°), which is different from the theoretical one, θc = 90°. The discrepancy is attributed to the existence of the adsorption layer near the TPCL.

Utilization of tannic acid into spherical structured carbons based on charge-transfer complexation with tetracyanoethylene acceptor: Liquid-liquid and solid-solid interactions

In this study, liquid-liquid and solid-solid interactions between tannic acid (TA) as a donor with tetracyanoethylene (TCNE) acceptor were investigated toward understanding the effect of starting material phase on the end product of a charge transfer (CT) reaction. The liquid-liquid interaction generated a reddish-brown, soluble CT complex, while the solid-solid interaction produced a deep-violet, solid CT complex. The stoichiometry of the interaction was obtained using an elemental analysis of the solid product and spectrophotometric titration and Job's method for the soluble product and these data both indicated a 1:5 (TA:TCNE) molar ratio. The UV–visible and IR measurements support the presence of π-π interactions between the TA donor and TCNE acceptor. The two CT complexes obtained from the two interactions were directly carbonized into particles. These resultant carbon particles were fully characterized using IR, XRD, SEM, and TEM. These analyses revealed that carbon particles with spherical morphology were obtained after the carbonization of the CT complex generated through the solid-solid interaction, while the liquid-liquid interaction led to carbon particles with semi-porous, irregular morphology.

Liquid-liquid phase equilibrium and interaction exploration for separation of azeotrope (2,2,3,3-tetrafluoro-1-propanol + water) with two imidazolium-based ionic liquids

For separating azeotropic mixture 2,2,3,3-tetrafluoro-1-propanol (TFP) and water, two kinds of imidazolium-based ionic liquids 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ([HMIM][OTf]) and 1-octyl-3-methylimidazolium trifluoromethanesulfonate ([OMIM][OTf]) were adopted to separate TFP and water. The liquid-liquid equilibrium behavior for the mixtures (water + TFP + [HMIM][OTf]) and (water + TFP + [OMIM][OTf]) were measured at temperature of 298.15 K and pressure of 101.3 kPa. The extraction ability of [HMIM][OTf] and [OMIM][OTf] was explored with partition ratio and selectivity. In the meantime, the hydrogen bond lengths, total electron density, interaction energies and deformation electron density were calculated to analyze the interactions between the [HMIM][OTf]/[OMIM][OTf] and (TFP/water). Also, the liquid-liquid equilibrium data was fitted by the NRTL model.

Liquid-liquid equilibrium measurements and interaction exploration for separation of isobutyl alcohol + isobutyl acetate by imidazolium-based ionic liquids with different anions

For separation of the azeotropic mixture isobutyl alcohol and isobutyl acetate, liquid-liquid extraction was adopted in this work and three imidazolium-based ionic liquids with different anions 1-butyl-3-methylimidazolium dihydrogen phosphate ([Bmim][H2PO4]), 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim][HSO4]) and 1-butyl-3-methylimidazolium methyl sulfate ([Bmim][MeSO4]) were chosen as extractants. The liquid – liquid equilibrium data (LLE) for isobutyl alcohol + isobutyl acetate + ([Bmim][H2PO4]/[Bmim][HSO4]/[Bmim][MeSO4]) were determined at 298.15 K and 101.3 kPa. The distribution coefficient and selectivity were calculated to evaluate extraction capability of the selected extractants. Furthermore, the σ-profiles and interaction energies based on conductor-like screening segment activity coefficient model (COSMO-SAC) were calculated to provide theoretical insight to interactions among the components. Also, the measured LLE data was correlated by the NRTL model and binary interaction parameters were regressed which is helpful for the separation process design and optimization.

Coeval interaction between magmas of contrasting composition (Late Carboniferous-Early Permian Santa Eulália-Monforte massif, Ossa-Morena Zone): field relationships and geochronological constraints

The Santa Eulalia-Monforte massif is a post-kinematic Late Carboniferous-Early Permian calc-alkaline composite massif (LC-EP) located in the Ossa-Morena Zone (OMZ, Portugal). This paper examines the field relationships between pinkish granites and mafic-intermediate rocks from the external ring of this massif and presents new U-Pb zircon age determinations. The estimated 206 Pb/ 238 U ages, 297±4Ma for the pinkish granite and 303±3Ma for a gabbro-diorite point to a short time interval between the crystallization of both magmas. At outcrop scale, contacts of the mafic-intermediate rocks with the host pinkish granite are sharp and corroborate this age relationship, but do not justify why the host-enclave contacts often has curved and irregular shapes, indicating liquid-liquid interaction. A full analysis of the distribution of U-Pb zircon ages and respective Th/U ratios suggests that the compositionally distinct magmas were roughly contemporaneous. The obtained ages also fit the LC-EP Iberian calc-alkaline suite that was formed contemporaneously to the development of the Iberian-Armorican Arc and when the Paleotethyan oceanic Plate subducted under the Eurasian active margin. Taking this geodynamic setting as a reference, the LC-EP Iberian calc-alkaline magmatism can be interpreted as most probably related to the Cimmerian cycle instead of the traditionally accepted model that ascribe a closer connection of this magmatism with the Variscan cycle. The Santa Eulalia-Monforte massif is a post-kinematic Late Carboniferous-Early Permian calc-alkaline composite massif (LC-EP) located in the Ossa-Morena Zone (OMZ, Portugal). This paper examines the field relationships between pinkish granites and mafic-intermediate rocks from the external ring of this massif and presents new U-Pb zircon age determinations. The estimated 206 Pb/ 238 U ages, 297±4Ma for the pinkish granite and 303±3Ma for a gabbro-diorite point to a short time interval between the crystallization of both magmas. At outcrop scale, contacts of the mafic-intermediate rocks with the host pinkish granite are sharp and corroborate this age relationship, but do not justify why the host-enclave contacts often has curved and irregular shapes, indicating liquid-liquid interaction. A full analysis of the distribution of U-Pb zircon ages and respective Th/U ratios suggests that the compositionally distinct magmas were roughly contemporaneous. The obtained ages also fit the LC-EP Iberian calc-alkaline suite that was formed contemporaneously to the development of the Iberian-Armorican Arc and when the Paleotethyan oceanic Plate subducted under the Eurasian active margin. Taking this geodynamic setting as a reference, the LC-EP Iberian calc-alkaline magmatism can be interpreted as most probably related to the Cimmerian cycle instead of the traditionally accepted model that ascribe a closer connection of this magmatism with the Variscan cycle.

Flow pattern diagrams of oil-water two-phase microflows and stable parallel flows obtained at low Reynolds numbers

Immiscible liquid-liquid parallel microflows are useful in many applications. However, the immiscible two-phase flow behaves nonlinearly and it is a challenging task to control and stabilize the liquid-liquid interface. Oleic acid-water immiscible two-phase flow in microchannels was studied in the present work. The flow pattern diagrams were measured. Four different flow patterns, namely the single-phase flow of the aqueous phase, the droplet flow with the organic droplet dispersed in water, the parallel flow, and the single-phase flow of the oil phase were identified. Special attention was paid on transitions between the parallel flow and the other patterns of flow. Parallel flow formed under a proper balance between the driving force, the friction resistance, and the interfacial tension. The liquid-solid interaction as well as the liquid-liquid interaction played an important role in manipulating the liquid-liquid interface. Adding surfactants in the aqueous phase and raising the temperature altered both the liquid-liquid interfacial tension and the liquid-solid interaction. This led to a rather complicated transition behavior between the parallel flow and the droplet flow. The surface states of the solid walls were found to be the dominant condition in controlling the flow patterns in many cases. By applying a certain level of vacuum at the outlet of the channels, the first layer of water attached to the solid walls became lower in density and thicker in thickness. The flow resistance for both phases were remarkably lowered. Stable parallel flows at the Reynolds numbers of the oil and the aqueous phases as low as 1 × 10−5 and 8 × 10−3, respectively, have been obtained without any chemical modifications of the solid surfaces, additional channel structures, or surfactants. A straight interface as long as several to tens of millimeters between the two immiscible liquid flows was successfully established and maintained stably by hours. Driving the flow with a negative pressure was verified to be a simple, effective, and controllable method for producing liquid-liquid immiscible parallel flows. It can be applied to various solvents and solutes and has potential in various applications, especially at low Reynolds numbers.

Formation of coffee-stain patterns at the nanoscale: The role of nanoparticle solubility and solvent evaporation rate

When droplets of nanoparticle suspension evaporate from surfaces, they leave behind a deposit of nanoparticles. The mechanism of evaporation-induced pattern formation in the deposit is studied by molecular dynamics simulations for sessile nanodroplets. The influence of the interaction between nanoparticles and liquid molecules and the influence of the evaporation rate on the final deposition pattern are addressed. When the nanoparticle-liquid interaction is weaker than the liquid-liquid interaction, an interaction-driven or evaporation-induced layer of nanoparticles appears at the liquid-vapor interface and eventually collapses onto the solid surface to form a uniform deposit independently of the evaporation rate. When the nanoparticle-liquid and liquid-liquid interactions are comparable, the nanoparticles are dispersed inside the droplet and evaporation takes place with the contact line pinned at a surface defect. In such a case, a pattern with an approximate ring-like shape is found with fast evaporation, while a more uniform distribution is observed with slower evaporation. When the liquid-nanoparticle interaction is stronger than the liquid-liquid interaction, evaporation always occurs with receding contact line. The final deposition pattern changes from volcano-like to pancake-like with decreasing evaporation rate. These findings might help to design nanoscale structures like nanopatterns or nanowires on surface through controlled solvent evaporation.

Water in Fuel Sloshing for Aircraft Fuel Tanks

Water is an unavoidable contaminant in aircraft fuel tanks. During an aircraft manoeuvre, fuel and water will slosh. The sloshing of two liquids (two-liquid sloshing) gives rise to a number of interesting phenomena which single-liquid sloshing does not experience. These include internal waves at the liquid-liquid interface and interaction between the motions of the two liquids. This paper investigated the ability of three commercial Computational Fluid Dynamics (CFD) modelling packages to accurately predict the pressures imparted on the tank walls of a rectangular tank when excited at near-resonant frequency while containing two liquids; water and fuel. A sloshing test rig was set-up to provide both qualitative (visual images) and quantitative (pressure data) results for comparison with the CFD calculations. The CFD calculations correlated well with the experimental results qualitatively and quantitatively. Snapshots of the sloshing show that CFD is able to model the wave modes reasonably well; and the pressure data show that CFD is able to simulate the pressure them were postulated.

Steam explosion experiments using partially oxidized corium

Two steam explosion experiments were performed in the TROI (Test for Real cOrium Interaction with water) facility by using partially oxidized molten corium (core material), which is produced during a postulated core melt accident in a nuclear reactor. A triggered steam explosion occurred in one case, but none occurred in the other case. The dynamic pressure and the dynamic load measured in the former experiment show a stronger explosion than those performed previously with oxidic corium. Meanwhile, a steam explosion is prohibited when the melt temperature is low, because the melt is easily solidified to prevent a liquid-liquid interaction. The partially oxidized corium could enhance the strength of a steam explosion due to the thermal energy from an exothermic chemical reaction between the water and the uranium metal with a sufficient superheat extracted during melting. The melt composition effect on a steam explosion load, which was not included during the nuclear design, needs to be included in it.

Solvent Design for Liquid Extraction Using Calculated Molecular Interaction Parameters

In this work, a molecular solvent design procedure for separation processes such as liquidliquid extraction, absorption, etc. is presented. Solvent molecular structures built from chosen sets of groups are generated in the three dimensional space by the use of a molecular graphics system (MGS) according to user specified combinatorial rules. The screening of the generated solvent candidates is performed according to distribution coefficients, selectivities, capacities, solvent losses etc. and which are the primary and most important criteria for, particularly, liquid-liquid extraction. The design procedure is based upon the UNIFAC model estimates of the activity coefficients at infinite dilution of the different compounds present in the extract and raffinate phases, where calculated molecular, rather than the existing liquid-liquid group interaction parameters, are used. The method is tested with two different industrial examples namely toluene/n-heptane and phenol/water systems.

Application of Flory-Huggins theory to ternary polymer-solvents equilibria: A case study

The ternary equilibrium data of the following systems: benzene/heptane/NBR at 60 °C (system 1), heptane/isooctane/PE at 25 °C (system 2), ethanol/water/CA at 20 °C (system 3) and ethanol/water/ P(E-co-VAc) at 32 °C (system 4), already reported in the literature, have been used and experimental results compared to predictions offered by the Flory-Huggins theory applied to ternary mixtures (one polymer and two liquids), with constant interaction parameters and negligible elastic contribution. Polymer-solvent interaction parameters have been determined from swelling in pure liquid, while liquid-liquid interaction parameters have been estimated from liquid-vapour equilibrium data curve fitting. It is shown that the Flory-Huggins theory offers reasonable prediction in the case of apolar liquids in an elastomeric matrix (system 1), while approximate isotherm patterns with significant discrepancies are obtained with apolar liquids in a thermoplastic (system 2). The equilibrium data of polar liquids in either homopolymer or copolymer (systems 3 and 4) can hardly be achieved by Flory-Huggins theory, even when a variable liquid-liquid interaction parameter is used. Implications in ternary diagram simulations and possible prediction improvements are discussed.

A proton relaxation study of immiscible liquid arrangement in microporous structures

The relaxation behaviour of immiscible hydrogenated liquids in well characterized microporous porcelain structures after a well defined stepwise preparation was studied to obtain information on the contact with surfaces and on the reciprocal arrangement in the pore space. Water-wet samples were fully saturated by brine, then brought to irreducible water saturation by oil and finally to residual oil saturation by brine. This step-wise preparation was repeated using deuterium oxide instead of brine. The observed changes of the 1 H spin-lattice relaxation curves reflected each step of preparation. The quantitative analysis of the curves gave evidence that no contact occurred between surfaces and oil because of a layer of water on the surface, except when only oil was present. On the contrary, when the wettability properties of the surfaces were changed, our data indicated that a contact between oil and walls occurred. So, the traditional picture of water-oil arrangement at the pore-length scale was verified for water-wet samples, whereas a more complex picture arose for oil-wet samples. While on one hand this study on model systems can help in explaining the information content of relaxation curves in more general conditions and systems, on the other hand it yields useful indications on some solid-liquid and liquid-liquid interaction effects in the displacement processes by water or by oil in microporous geometries.

Liquid-liquid techniques in phosphorus chemistry

Abstract