Binary Solutions Research Articles

Experimental and simulation studies on the improvement of coal dust pollution by an aqueous solution of sodium α-alkenylsulfonate and amino acid-based surfactants

The use of surfactants is crucial for the prevention and control of coal dust pollution in coal mining operation areas, yet there still exist many challenges in the control of coal dust pollution. In this paper, the green biomass-based amino acid surfactant sodium myristoyl glutamate (SMG) and the anionic surfactant sodium α-alkenyl sulfonate (AOS) were selected to investigate the improvement of coal dust wettability by single and binary solutions from the macroscopic and microscopic perspectives. Molecular simulations were used to reveal the microscopic mechanism of the wettability of coal dust by the different solutions. Experimental measurements showed that the contact angle of the AOS + SMG aqueous solution was as low as 13.8° on a coal surface. Coating the coal dust with the AOS + SMG solution reduced the surface tension by 12.02% compared to coating the coal with a single component solution. Additionally, the use of the binary AOS + SMG solution increased the hydrophilic group content in the coating by 11.77% compared to a single component solution, and the linkage between hydrophilic groups was enhanced, which pulls the water molecules to wet the coal dust. These research results should provide a new way to promote more environmentally friendly coal dust pollution control technology.

Size effects on spinodal decomposition

Abstract We examine the influence of grains size on the stability of polycrystalline coherent binary solid solutions. By assuming that the grains are isotropic, we find that the tendency for instability decreases as the radius of the grains decrease. We also find that a temperature-dependent critical grain radius exists below which the tendency for instability vanishes and the grains are stable, with respect to infinitesimal composition fluctuations, for any initial composition. We find that the critical grain radius decreases monotonically as the temperature decrease. If the radius of the grains is smaller than the minimum critical grain radius the grains are stable for any temperature and initial composition.

Physiochemical study of 1-methyl imidazole trifluoro methane sulfonate ionic liquid in aqueous and aqueous amino acid solutions at different temperatures

The experimental density and speed of sound of 1-methyl imidazole trifluoro methane sulfonate ionic liquid in aqueous binary ([MIm][OTf]+H2O) solution and aqueous ternary ([MIm][OTf] + 0.05 mol.kg−1 aqueous glycine) solution are reported in the dilute concentration range (0.06 to 0.16 mol.kg−1) at the temperature between 288.15 and 318.15 K with 5K interval and at atmospheric pressure. These density (ρ) and speed of sound (u) data are utilized to derive various significant thermophysical parameters namely apparent molar volume of solute (Vϕ), isentropic compressibility of solution (κs) and apparent molar isentropic compressibility of solute (KS,ϕ). The limiting apparent molar volume (Vϕ0) and limiting apparent molar isentropic compressibility (KS,ϕ0) of [MIm][OTf] are estimated by extrapolation methods. By using Vϕ0and KS,ϕ0data of the studied binary and ternary systems, the values of transfer volumes i.e. volume changes due to transfer (ΔtrVϕ0)and transfer compressibility i.e. compressibility changes due to transfer(ΔtrKsϕ0) from aqueous to aqueous amino acid solution are estimated. The observed ΔtrVϕ0and ΔtrKsϕ0values are temperature dependent. The outcomes of this investigation are framed within the context of solute-solute and solute-solvent interactions.

Optimization and modelling of magnesium oxide (MgO) photocatalytic degradation of binary dyes using response surface methodology

Textile industry dye effluent contains a mixture of different kinds of dyes. Many times, photocatalysis is targeted as a solution for the treatment of dye effluent from the textile industry. Many researches have been published related to the photocatalysis of single textile dyes but in the real-world scenario, effluent is a mixture of dyes. Magnesium oxide (MgO) is used as a photocatalyst to treat a mixture (binary solution) of Methylene blue (MB) and Methylene violet (MV) along with individual MB and MV dyes in this article. MgO shows remarkable photocatalytic activity at about 93 and 88% for MB and MV dye in binary solution within 135 min. Furthermore, to study the influence of process parameters, experiments are designed with the help of the central composite design (CCD), and Response surface methodology (RSM) is used to study the interactions between parameters. For this study, five parameters are selected i.e., Photocatalyst dosage, initial concentration of both dyes, time of exposure to the light source, and pH of the binary solution. The photocatalytic process is also optimized and finally optimization of process parameters is validated with an experiment. The result of the validation experiment is very close to the predicted photocatalytic activity.

Characterizing boiling behaviors in water/ethanol binary droplet impact on a heated plate

This work experimentally investigates the transition boiling behaviors of water/ethanol binary droplets impact on a heated smooth aluminum alloy plate with a high-speed imaging system, forming a more finely defined impact behavior regime map. The dynamic Leidenfrost point temperature exhibits a non-monotonic variation trend with ethanol fraction. Binary droplets exhibit two characteristic boiling behaviors at specific temperatures (Ts) and droplet compositions (Φe), including corona boiling and prompt boiling, distinguished by the elevation of a crown-shaped thick liquid lamella and the prompt generation of numerous secondary droplets from the contact line, respectively. Both boiling behaviors are featured with the violent breakup of parent droplet into about 10 or more fragment droplets (secondary droplets with D ≥ 0.3 mm) and the short residence times on the wall, while exhibiting different splash angle distributions of satellite droplets (secondary droplets with D < 0.3 mm). Characteristic parameter analysis of the two boiling behaviors is conducted to provide qualitative mechanistic explanations. Corona boiling occurs at Φe = 25% & 50% with a lower temperature range (Ts ≤ 200 ℃), the liftoff of the liquid layer is attributed to the combined effect of decelerated wetting speed caused by evaporation and the vapor-induced lift. Prompt boiling occurs at Φe = 25% & 50% with Ts ≥ 220 °C and Φe = 75% with Ts < 200 °C, the intensity of the bubble cloud determines whether the central part of the droplet forms a jet or a liquid bulk filled with microbubbles. This work will provide some new insights into the boiling behaviors and the regulation of secondary atomization of binary solution droplets impact studies.

Densities, Excess Molar Volumes and Excess Refractive Indices for Binary Solutions of D2O and H2O

Densities, Excess Molar Volumes and Excess Refractive Indices for Binary Solutions of D2O and H2O

Thermo-responsive selective recovery of protonated dyes by carbon-doped boron nitride-(N-isopropylacrylamide) composite gel

Approximately 280,000 tons of textile dyes are discharged into water bodies annually worldwide, which have the potential to be transformed into resources through selective recovering them from the effluents. Herein, a series of thermo-responsive carbon-doped boron nitride composite gels (TBCN) have been successfully synthesized, with optimum mass ratio BCN:NIPAM = 0.2:1 and pH 7. SEM-EDX, FTIR, XPS and theoretical calculation support that carbon-doped boron nitride (BCN) was uniformly dispersed inside the N-isopropylacrylamide (NIPAM) matrix through van der Waals interaction and hydrogen bonding. TBCN samples selectively recover protonated dyes from binary dyes solution through adjusting temperature instead of pH, which reduce the secondary pollution of acidic wastewater and are easier to recycle than powder adsorption materials. The removal rates of neutral red (NR)and malachite green (MG)by TBCN-2 reach 98.80 % and 98.40 %, which are obviously higher than methyl orange (MO: 42.48 %) and methylene blue (MB: 44.27 %). Through rising the temperature to 40 ℃, the adsorbed NR and MG are released, and the recovery rates are 78.50 % and 77.32 %, whereas those of MO and MB are only 26.05 % and 24.53 %. Furthermore, NR (or MG) can be selectively recovered from the mixed solution of NR-MB and NR-MO (or MG-MB and MG-MO) by TBCN-2, with the maximum removal rate of 93.51 %. For cycle stability, TBCN-2 can be used repeatedly at least four times with recovery rate＞58.80 %. TBCN-2 is an eco-friendly material and has good application prospect in dye resource utilization.

Molecular and electrostatic origins of mixed salt partitioning phenomena in uncharged poly(ethylene oxide)-based membranes

Despite the increasing interest in membranes for water purification and resource recovery from aqueous electrolyte mixtures, few studies rigorously investigate the influence of salt solution composition (e.g., mole fraction and total salt concentration) on membrane material properties such as partition coefficients. Here, we systematically investigate the influence of solution composition on the partitioning of ionic species from binary aqueous salt solutions into crosslinked poly(ethylene glycol) diacrylate membranes at fixed ionic strength. These results are compared to partition coefficients observed for pure salt solutions. We observe large systematic deviations between the pure salt and mixed salt ion partition coefficients, indicating that the single salt partition coefficients that are often reported do not describe the more complex and realistic mixed salt scenario. Free energy calculations from molecular dynamics simulations, coupled with equilibrium thermodynamic modeling, indicate that mixed salt partitioning trends result from (i) different ions exhibiting different affinities for the membrane and (ii) the constraint of global electrical neutrality within the membrane. With this physical insight, we develop a simple approach to predicting the concentration of various ions in a membrane equilibrated with a mixed salt solution which requires no adjustable parameters.

Hydrogen bond complexation of ethanol with chlorobenzene: FTIR studies

ABSTRACT FTIR spectral studies has been carried out on ethanol (EtOH), chlorobenzene (PhCl) and their binary solutions at various EtOH/PhCl mole fractions. The bonded O − H stretching region has been deconvoluted into four Gaussian peaks centring at 3543.6, 3489.4, 3406.3 and 3254.3 cm−1. The first and the last peaks have been assigned to the hydroxyl stretching bands of dimer and tetramer, while the remaining two to the trimer bands. The presence of dimer in liquid PhCl has been confirmed by the experimental C − Cl stretching bands. Experimentally, two C − Cl stretching bands have been observed, which fall outside the 1096–1089 cm−1 range reported for chlorobenzenes in literature. The positional changes in O − H , C H 3 , C H 2 , C − H and C − Cl stretching bands in the spectrum of the solutions have been analysed in terms of heteromolecular H-bond interactions. This analysis shows that the classical O − H ⋯ Cl hydrogen bonds are the dominant interaction forces.

Theoretical and practical investigation of ion-ion association in electrolyte solutions.

In this study, we present a new equation of state for electrolyte solutions, integrating the statistical associating fluid theory for variable range interactions utilizing the generic Mie form and binding Debye-Hückel theories. This equation of state underscores the pivotal role of ion-ion association in determining the properties of electrolyte solutions. We propose a unified framework that simultaneously examines the thermodynamic properties of electrolyte solutions and their electrical conductivity, given the profound impact of ion pairing on this transport property. Using this equation of state, we predict the liquid density, mean ionic activity coefficient, and osmotic coefficient for binary NaCl, Na2SO4, and MgSO4 aqueous solutions at 298.15K. Additionally, we evaluate the molar conductivity of these systems by considering the fraction of free ions derived from our equation of state in conjunction with two advanced electrical conductivity models. Our results reveal that, while ion-ion association has a minimal influence on the modification of the predicted properties of sodium chloride solutions, their impact on sodium and magnesium sulfate solutions is considerably more noticeable.

Guest-induced supramolecular helices and its application in L-Arg detection and L-Arg controlled reversible morphology modulation

A novel AIE supramolecular polymer (BPK) was synthesized by bis(2-hydroxy-1-naphthaldehyde) terephthalo hydrazone functionalized pillar [5]arene and cross-linked using a bis(4.4-dipyridinium salt)cross-linker via host-guest complexation. BPK exhibited strong aggregation-induced emission (AIE) in binary solutions of DMSO/H2O. BPK could be an AIE-based sensor with specific fluorescence sensing ability for L-Arg in water. The detection limit of BPK for L-Arg was 3.95 × 10−7 M, and other amino acids did not interfere with the sensing process. Moreover, in a pure DMSO solvent, BPK can self-assemble into a fibrous structure of the right-hand spiral by guest-induced supramolecular helices. At 80 % water content, BPK undergoes a morphological transformation into supramolecular polymer. Intriguingly, BPK exhibits a reversible transformation from a polymer to a nanosphere through the alternating addition of trifluoroacetic acid and arginine. Additionally, the fluorescence of BPK demonstrates an "on-off" switch. This phenomenon is attributed to the formation and disruption of intermolecular hydrogen bonds. The reversible manipulation of polymer materials' morphology and optical properties holds significant potential in biomedicine and smart materials.

Study of structuredness and hydrogen bonding in binary solutions using microwave technique

Study of structuredness and hydrogen bonding in binary solutions using microwave technique

Lower bounds for the rank of a matrix with zeros and ones outside the leading diagonal

We have found a lower bound on the rank of a square matrix, where every entry in the leading diagonal is neither zero nor one, but every entry outside the leading diagonal is either zero or one. The rank of such a matrix is at least half the order of the matrix. Under an additional condition, the lower bound is one higher. This condition means that some auxiliary system of linear equations has no binary solution. Examples are given showing the achievability of the lower bound. This lower bound on the rank allows us to reduce the problem of finding a binary solution to a system of linear equations, where the number of linearly independent equations is sufficiently large, to a similar problem in a smaller number of variables. Restrictions on the existence of a large set of solutions are found, each of which differs from binary one by the value of one variable. In addition, we discuss the possibility of certifying the absence of a binary solution to a system of a large set of linear algebraic equations. Estimates of the running time for calculating the rank of a matrix with the SymPy computer algebra system are also given. It is shown that the matrix rank over the field of residues modulo a prime number is calculated in less time than is usually required to calculate the rank of a matrix of the same order over the field of rational numbers.

Binary color adsorption by zinc@magnetite nanocomposites: Robust parametric optimization using Taguchi method

AbstractThe goal of the current study was to determine the optimal level (value) of adsorption process variables for the adsorption of color from binary aqueous solution. The impact of key adsorption factors, including adsorbent dose, initial color concentration, and contact time, on the color removal effectiveness of Zinc@magnetite nanocomposites (Zin@Fe3O4(ME) produced from bacterial extracts and Zin@Fe3O4(M) produced from bacterial cell mass), has been examined. Utilizing an L9 orthogonal array (OA), average values and the SN ratio for each variable at three diverse points are calculated. ANOVA has determined the most advantageous optimum conditions for raw and SN data. According to the study, the adsorbent dose is shown to be the most important parameter for color adsorption, while contact duration is determined to be the least important factor based on Pareto chart analysis. The percentage of color removal at optimal values for Zin@Fe3O4(M) and Zin@Fe3O4(ME) nanocomposites, respectively, was found to be 81% and 73%. The optimal parameters were found to be 12.5 mg of adsorbent, 125 mg/L initial dye concentration, and 90 min of contact time at pH 7, room temperature. The confirmatory experiments conducted under optimized conditions revealed a higher percentage of color eliminated than was optimized in each test run of the Taguchi design, proving the credibility of the process variables optimized within the designated experiments.

Recovery of lithium by pseudocapacitive electrodes in capacitive deionization

Lithium is a crucial component in rechargeable lithium-ion batteries for many applications, including the powering of electric vehicles and stationary energy storage systems. This investigation focused on two hybrid pseudocapacitive materials, the polystyrene sulfonate-MXene composite (PM) and the sodium titanate/graphene oxide composite (NG), for lithium ions recovery from aqueous Li+ resources. This was achieved by selectively removing unwanted divalent Ca2+ and Mg2+ ions, as well as monovalent K+ ions, through capacitive deionization (CDI) using a single-cell system, resulting in a final solution enriched with Li+ ions. Based on the ion selectivity order observed previously as Mg2+≈ Ca2+ >K+ > Li+, a series of CDI experiments were conducted with sequential steps to remove more selective ions first and to obtain a lithium-enriched solution with higher purity and maximum extracted fraction. Both PM and NG electrodes demonstrated promising performance when tested in binary, ternary, and quaternary ionic solutions with the recovered lithium solution purity in the range of 59.09 %-95.94 % and 59.75 %-77.17 %, respectively. Further, the highest enrichment factor values observed were SLi+,Mg2+; 268.1 for PM and SLi+,Ca2+; 44.25, for NG electrodes. The PSS-modified MXene composite electrode in obtaining the Li+ solution with the highest purity when separated Ca2+ from a binary solution. These findings offer valuable insights into the selective electrosorption of divalent ions over lithium ions through the utilization of ion intercalation pseudocapacitive nanocomposite electrodes. The obtained results hold significance in advancing novel non-precipitation techniques for the recovery of lithium ions from aqueous lithium resources.

Self and hetero-association in Benzaldehyde/Quinoline − Formamide solutions: Time Domain Reflectometry studies

The complex permittivity spectra of binary solutions of Benzaldehyde (PhCHO)/Quinoline (QUI) with Formamide (FMD) have been obtained at different mole fractions of FMD in the frequency range from 10 MHz to 30 GHz using the Time Domain Reflectometry (TDR) technique. The complex permittivity spectra have been fitted with Debye function. Dielectric relaxation time values have been interpreted in terms of the nature and size of the self and hetero associates of the binary solutions. The effective Kirkwood correlation factor (geff) has been correlated with closed and open associates of the solutions. The geff∼0.51 is the characteristic value of closed dimers. It appears that geff∼0.75 signifies the presence of both closed and open dimers. The Excess static dielectric constant (εE) shows negative deviation. The corrective Kirkwood correlation factor (gf) and Bruggeman factor (fB) have been used to investigate the strength of the H-bond interactions. The Geometry optimization has been carried out using Density Functional Theory (DFT) with B3LYP/6–311++G (d, p) basis set. Population analysis on the optimized geometries shows that PhCHO has 53.61 and 46.39 % closed and open geometries, respectively, while FMD has 17.11 % open dimers and remaining are closed dimers.

A new synergistic hydrocolloid with superior rheology: Locust bean /xanthan gum binary solution powdered by different drying methods

In the current study, a novel gum powder containing locust bean and xanthan gums was prepared by three different drying methods of their synergistic aqueous solutions: direct cabinet drying (CD), drying after alcohol precipitation (PD), and direct freeze drying (FD). The purpose of this process is to develop ready-to-use synergistic gum powders with improved rheological properties by modifying intermolecular interactions. Significant improvements in viscosity, consistency efficiency and pseudoplastic character were observed for PD, followed by CD and FD, as well as the higher values of G′ and G″ values of PD, indicating a stronger entanglement network development between the macromolecules for PD. PD exhibited better elasticity and shear resistance compared to FD and CD in the strain sweep test. In Lissajous curves, straight line shapes were found for synergistic solutions at low strain, which continued for increasing strain values for PD and CD. However, the pronounced viscous behavior was found for FD at 500% strain. Compared to CD and FD, PD exhibited a more desirable thixotropic character. A lower zeta potential was observed in the production of synergistic gums using the PD process. Gel strength was found to be higher for PD. Therefore, PD was a more effective method to produce a ready-to-use synergistic powder with better viscoelastic properties and a more stable solution.

Synthesis and Thermal Decomposition of High-Entropy Layered Rare Earth Hydroxychlorides.

The synthesis of multicomponent and high-entropy compounds has become a rapidly developing field in advanced inorganic chemistry, making it possible to combine the properties of multiple elements in a single phase. This paper reports on the synthesis of a series of novel high-entropy layered rare earth hydroxychlorides, namely, (Sm,Eu,Gd,Y,Er)2(OH)5Cl, (Eu,Gd,Tb,Y,Er)2(OH)5Cl, (Eu,Gd,Dy,Y,Er)2(OH)5Cl, and (Eu,Gd,Y,Er,Yb)2(OH)5Cl, using a homogeneous hydrolysis technique under hydrothermal conditions. Elemental mapping proved the even distribution of rare earth elements, while luminescence spectroscopy confirmed efficient energy transfer between europium and other rare earth cations, thus providing additional evidence of the homogeneous distribution of rare earth elements within the crystal lattice. The average rare earth cation radii correlated linearly with the unit cell parameters (0.868 < R2 < 0.982) of the high-entropy layered rare earth hydroxychlorides. The thermal stability of the high-entropy layered rare earth hydroxychlorides was similar to that of individual hydroxychlorides and their binary solid solutions.

Improving energy storage properties of NN-NBT ceramics through compositional modification

Na0.5Bi0.5TiO3(NBT)-based ceramics are materials with good energy storage properties and non-ergodic relaxation ferroelectric properties, as well as high Curie temperature and good temperature stability. Herein, a new approach was devised to adjust the non-ergodic relaxation ferroelectric characteristics of Na0.5Bi0.5TiO3(NBT)-based ceramics by introducing NaNbO3 into Na0.5Bi0.5TiO3(NBT) (x NN-(1-x) NBT, where x= 0.17, 0.19, 0.21, 0.23, and 0.25). To overcome limitations of NBT, additional constituents with antiferroelectric properties were introduced to create binary solid solutions with NBT to yield NN-NBT ceramics with antiferroelectric properties for optimized energy storage applications. As-obtained NN-NBT ceramics revealed multiphase structures with rhombic (R3c) and tetrahedral (P4bm) phases. Coexisting strongly and weakly coupled polar nanoregions (PNRs) resulted in relatively high polarization (Pmax) and reduced polarization of reflection (Pr). The optimized 0.21NN-0.79NBT ceramic exhibited recoverable energy storage density of ≈2.84 J·cm−3 at 180 kv·cm−1 with energy storage efficiency of 78%. Structural characterization indicated the existence of intermediate phases modulation phases with coexisting antiferroelectric phase and relaxation ferroelectric phase. Overall, proposed NBT-based non-ergodic relaxation ferroelectric ceramics look promising for effectively improving energy storage performance, providing new prospects for the development of advanced pulse capacitors.

Lignin reinforced tough, adhesive and recoverable protein organohydrogels for wearable strain sensing under sub-zero temperatures

Protein-based hydrogels with promising biocompatibility and biodegradability have attracted considerable interest in areas of epidermal sensing, whereas, which are still difficult to synchronously possess high mechanical strength, self-adhesion, and recoverability. Hence, the bio-polymer lignosulfonate-reinforced gluten organohydrogels (GOHLx) are fabricated through green and simple food-making processes and the following solvent exchange with glycerol/water binary solution. Ascribing to the uniform distribution of lignosulfonate in gluten networks, as well as the noncovalent interactions (e.g., H-bond) between them, the resultant GOHLx exhibit favorable conductivity (~14.3 × 10−4 S m−1), toughness (~711.0 kJ m−3), self-adhesion (a maximal lap-shear strength of ~33.5 kPa), high sensitivity (GF up to ~3.04) and durability (~3000 cycles) toward shape deformation, which are suitable for the detection of both drastic (e.g., elbow and wrist bending) and subtle (e.g., swallowing and speaking) human movements even under −20 °C. Furthermore, the GOHLx is also biocompatible, degradable, and recoverable (by a simple kneading process). Thus, this work may pave a simple, green and cheap way to prepare all-biomass-based, tough, sticky, and recoverable protein-based organohydrogels for epidermal strain sensing even in harsh environments.