Apparent Molar Volumes Research Articles

Volumetric-acoustic investigations of antihypertensive drug in aqueous acetaminophen system

Captopril is an antihypertensive drug used to lower the blood pressure in living organisms. In order to arbitrate and understand the synergy between antihypertensive drug viz., captopril and antipyretic drug acetaminophen in aqueous system, the density and sound velocity at different temperatures (293.15 to 318.15) K with temperature interval of 5 K were measured using Anton Paar density sound velocity meter (DSA5000M). The experimental measured data were further used to calculate volumetric and acoustic parameters such as apparent and partial molar volume, apparent and partial molar isentropic compressibility, partial molar expansibility, Hepler’s constant, compressibility hydration number, and intermolecular free length. Positive values of apparent molar volume (ϕv) and negative values of apparent and partial molar compressibility (ϕk and ϕko) of captopril in water and aqueous acetaminophen solution has been shown strong intermolecular interactions in solutions. Negative values of Hepler's constant indicate the structure breaking behavior of drug in water.

Toward an understanding of volumetric and isentropic compressibility behavior of imidazolium-based ionic liquids in aqueous polymer solutions

ABSTRACT A systematic experimental density and sound velocity measurement was carried out for imidazolium-based ionic liquids (ILs) in pure water and in aqueous solutions of 0.03 w/w of water-miscible polymers with different structures and molar masses at T= (288.15, 293.15, 298.15, 303.15 and 308.15) K and p = 84.5 kPa. The ILs under investigation are 1-butyl-3-methylimidazolium hydrogen sulphate ([C4mim][HSO4]) and 1-butyl-3-methylimidazolium bromide ([C4mim]Br). The effects of temperature, polymer type, and IL anion type on the various volumetric and compressibility properties, such as apparent molar volume, isentropic compressibility, apparent molar isentropic compressibility, and infinite dilution apparent molar properties for transfer of ILs from water to aqueous polymer solution were scrutinised. From the gathered results, ion-water interactions, ion-ion interactions at finite concentration, and water-structure breaking character for aqueous solutions of [C4mim][HSO4] are more considerable than aqueous solutions of [C4mim]Br. However, [C4mim]Br-polymer interactions are more favourable than interactions between [C4mim][HSO4] and the studied polymers.

Thymoquinone-Micellar Interactions: A physico-chemical investigation at molecular level

Thymoquinone (TQ) is considered the most-active component of the well-known essential oil of the black cumin/seeds (Nigella sativa L.), also known for its wide-spectrum anticancer and other pharmacological potentials since ancient times. Apart from its thermo- and photo-sensitive nature, TQ has also been reported to demonstrate strong hydrophobicity and low bioavailability. These physico-chemicals, properties hinder the development of a successful oral dosage formulation. Interaction of the pharmacologically active molecule with biological membranes is crucial step to manifest health-related effects. However, further insight into the biophysical interactions of “active” natural chemotherapeutics with cellular membranes can play a vital role in designing and developing new anti-cancer regimens. In this context pseudo-membrane models comprising ionic and non-ionic micelles offer a useful way to explore in vitro drug-membrane interactions at the molecular level. The present study focuses on the physicochemical interactions of a thymoquinone (TQ) with micelles of ionic (dodecyl trimethylammonium bromide, DTAB; and sodium dodecyl sulfate, SDS) and non-ionic (tween-80 and TX-100) surfactants at the molecular level in aqueous medium. Volumetric and acoustic parameters (apparent molar volume (ɸV), isentropic compressibility (Ks), apparent molar isentropic compressibility (ɸk), specific acoustic impedance (Z), relative association (RA), intermolecular free length (Lf)) are calculated from experimental data of density and sound velocity and interpreted in terms of solute/solvent–solute/solvent interactions using the co-sphere overlap model and the electrostriction effect. Further, UV spectroscopy and conductivity studies are used to predict the locus of TQ in the micelles, binding constant (Kb), partition coefficient (Kc), and free energy changes of TQ-micelle systems in the presence of surfactants. The results show that the binding and partitioning of TQ is more significant with TX-100 as compared with other ionic and non-ionic surfactants used.

Physico-chemical and spectroscopic study of some biologically potent molecules in aqueous solution of an anti-malarial drug molecule with reference to diverse molecular interactions simultaneously optimized by DFT

The various molecular interactions of amino acids, l-Asparagine (L-Asn) and l-Glutamine (L-Gln) in the aqueous solutions of Chloroquine diphosphate (CDP) had been explored comprehensively by various physicochemical as well as spectroscopic methodologies. Here we exposed the chemistry of l-Asparagine and l-Glutamine in aqueous solution of CDP by means of the apparent molar volume (ϕv), limiting apparent molar volume (ϕv0), viscosity B coefficients, molar refraction (RM), limiting molar refraction (RM0), limiting slope of surface tension and the studies revealed dominancy of solute-solvent interaction, over the solvent-solvent and solute-solute interactions in solution. A significant evidence on the nature of solute – solvent interaction obtained from 1H as well as 13C NMR spectroscopic measurement. CDP – amino acids binding constants were calculated from UV–visible spectroscopic measurement, showing significant binding ability. This work has a theoretical background after the practical outcomes, which was executed by the DFT calculations.

Molecular Interaction Activities of Phenylephrine Hydrochloride with Aqueous System by using Physicochemical Properties at 298.15, 303.15, 308.15 and 313.15 K

Abstract: The solubilizing tendency of the phenylephrine hydrochloride (PHC) with water was supported by the intermolecular interaction (IMI). The effect of PHC concentration with water molecules on the interaction by using physicochemical properties (PCP) was investigated at 298.15, 303.15, 308.15 and 313.15 K. The PCP such as density (ρ, g cm -3 ), Apparent Molar Volume (Vϕ,cm 3 ·mol−1 ), viscosity (η, mPa.s), and surface tension (γ,mNm-1 ) of PHC in aqueous solution have been determined at 298.15, 303.15, 308.15 and 313.15 K. The PCP determine the state of intermolecular forces (IMF) between PHC and water (W). The concentration of PHC ranged from 0.02- 0.10 millimolar (mM) as a binary system in water. This study shows molecular interaction mechanism moderated through PCPs to assess state of IMF produced on PHC-Water interaction at 298.15, 303.15, 308.15 and 313.15 K which revealed that structural potential of PHC with water responsible for develop interaction. The PCP data confirms structural behavior of PHC with water for intermolecular interaction and increases with increasing concentration of PHC. The temperature dependent solubility determined at 298.15, 303.15, 308.15 and 313.15 K which indicates that on increasing temperature the significant change found in PCP. This is due to structure breaking effects of PHC with water furnished disruption of hydrogen bond (HB) in water and electrostatic interactions (EI).

PH dependent physicochemical signatures of amino acids in aqueous buffers: Thermodynamic analysis

The physicochemical signatures such as apparent molar volume (V2,Φ), isoentropic compressibilities (KS,2,φ), and dilution enthalpies of a series of amino acids (AAs) glycine (Gly), L-alanine (Ala), DL-α-amino-n-butyric acid (ABA), L-valine (Val) and L-leucine (Leu) have been measured at various pH values (pH = 2, 5 7 and 9) at a buffer molality of 0.1 mol kg−1 of water at 298.15 K. The data obtained from high sensitivity densimeter and sound analyser along with ultrasensitive isothermal titration calorimetry has been analyzed to evaluate the values of standard partial molar quantities such as for volume at infinite dilution (V2,m0), compressibility KS, 2,m0 and dilution enthalpy (ΔdilH0) of the AAs together with standard partial molar quantities of transfer of these solutes from water to aqueous buffer systems at these pH values. The linear correlation of V2,m0 for this series of AAs against number of carbon atoms in their alkyl chain has been used to evaluate the contribution of zwitterionic end groups (NH3+, COO–), the CH2 group, and other parts of alkyl chains of the AAs to the overall value of V2,m0. The results of standard partial molar transfer properties on volumes, compressibilities and enthalpies of dilution from water to aqueous buffer systems at various pH values have been connected and explained in terms of ion-polar, ion-hydrophilic, hydrophobic-hydrophobic and ion-hydrophobic interactions of the participating groups. These thermodynamic signatures when compared at different pH values suggest that at electrostriction of water dominates at pH 2. Such physicochemical properties of constituents of proteins such as amino acids have not been reported earlier. Thus, the results demonstrate that the interaction of individual amino acid residues with the buffer components does not lead to significant change in their physicochemical properties thereby permitting their use in obtaining mechanistic insights into systems of biological interest consisting of these constituents.

Investigation of intermolecular interactions of l-Valine and l-Phenylalanine with muscle relaxant drug mephenesin molecule prevalent in aqueous solution by various physico-chemical methods at T=298.15K–313.15K

A complete chemical analysis of significant intermolecular interactions of l-Valine (L-Val) and l-Phenylalanine (L-Phe) with Mephenesin (MEPN) molecules in aqueous solution has been studied by different physicochemical methodologies at various temperatures (T = 298.15 K–313.15 K at an interval of 5 K) and concentrations (0.001 mol kg−1, 0.003 mol kg−1, 0.005 mol kg−1) of aqueous MEPN solution. The limiting apparent molar volume (φV0) and experimental slope (SV*) values are found from the equation of Masson, viscosity A and B-coefficient determined using the equation of Jones-Doles, molar refraction (RM) and limiting molar refraction (RM0) derived by the Lorentz-Lorenz equation, express that in our experimental solution of amino acids (AAs) in aqueous MEPN, the solute-solvent interaction predominates over the solute-solute and solvent-solvent interactions for these ternary solutions. These are also justified by the measurement of various thermodynamic parameters, free energy of activation of viscous flow per mole of solvent(Δμ1°#) and solute (Δμ2°#), activation of viscous flow of enthalpies (ΔH°#) and entropies (ΔS°#). The characteristics of structure-breaking of solutes in the aqueous drug solution have been identified by Hepler's method and dB/dT value. The spectroscopic methods like UV–visible and proton-NMR studies help to explicate the strong AA-MEPN interactions in the solution phase and obtain a good correlation with theoretical studies. Theoretical investigations are checked to authenticate the experimental observations and according to both studies, L-Phe-MEPN interaction is greater than L-Val-MEPN interaction. The experimental and correlated research data are useful for the development of model combinations of AAs with drug molecules in pharmaceutical and medicinal chemistry.

Thermodynamic characterization of aqueous solutions of NaCl, KCl, MgCl2 and CaCl2: volumetric, acoustic, viscometric and computational analysis

The volumetric and acoustic properties of alkali and alkaline earth metal salts are ubiquitous in numerous biological and non-biological processes and accurate formulation of their thermophysical properties is a fundamental prerequisite for complete exploration of their diverse applications. To meet this purpose, in this investigation, we herewith report the systematic data of densities ρ, speed of sound u and viscosity η of aqueous binary solutions of the prominent alkali and alkaline earth metal salts viz. NaCl, KCl, MgCl2, and CaCl2 at seven different temperatures T = (288.15–318.15 K) and ambient pressure over the wide concentration range of (0.002–1) mol∙kg−1.These experimental data have been further employed to obtain some important thermodynamic parameters, viz, the apparent molar volume of solute Vϕ, limiting apparent molar volume of solute Vϕ0, isentropic compressibility of solution κS, apparent molar isentropic compression of the solute KS,ϕ, limiting apparent molar isentropic compression of solute KS,ϕ0 and apparent molar expansibility Eϕ0. Further, the coefficient of thermal expansion α*, the second-order derivative of limiting apparent molar volume ∂2Vϕ0/∂T2, Jones-Dole equation viscosity A, B, D coefficients, temperature derivative of B coefficient i.e. dB/dT, activation parameters for viscous flow and hydration number nH have also been computed. The results obtained have been used to elucidate different interactions taking place in the aqueous electrolytic solutions. To corroborate the experimental results, quantum chemical calculations were performed using density functional theory (DFT) by Gaussian software package. The calculations included an analysis of molecular orbitals, with particular emphasis on the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).

Interactional behaviour of analgesic drugs in aqueous solution of caffeine at different temperatures using multi-technique approach

Drug combination therapies have been a promising strategy to overcome drug resistance. However, unexpected drug–drug interaction may cause adverse reactions, which puts patients in danger. Keeping this in mind, the interactions between pain killers, paracetamol (PCM), and ibuprofen sodium with caffeine (CAF) have been studied. Apparent molar volumes ( V2,ϕ) and apparent molar isentropic compression ( Ks,2,ϕ) for analgesic drugs in aqueous (1, 2, 5, and 10 mmol·kg−1) CAF solutions have been determined from measured densities, ρ, and speeds of sound, u, respectively, at T = 288.15–318.15 K and at pressure p = 101.3 kPa. The results have also been interpreted in terms of various interactions occurring in the mixed solution. Calorimetrically determined negative values of ΔtrΔdil H0 indicate the exothermicity and thus the occurrence of energetically more favorable process. The hyperchromic shift (UV absorption) in the spectra of PCM in aqueous solution of CAF suggests the dominance of solute–cosolute interactions through the hydrophobic–hydrophobic/hydrophilic groups (1H NMR) of PCM + CAF system.

Insight of interaction in kojic acid/urea derivatives deep eutectic solvent from physicochemical characterization and computation simulation

In recent years, the excellent performance of deep eutectic solvents (DES) has garnered increasing attention in the pursuit of sustainable solvents. This study employs natural and biodegradable kojic acid (KA) as a hydrogen bond donor (HBD) and environmentally friendly urea derivatives as hydrogen bond acceptor (HBA) to construct a series of novel type V KA/urea derivatives DESs. The as-obtained DESs were systematically characterized by density, viscosity, refractive index, speed of sound, thermal gravimetric analysis, FT-IR and NMR spectrums. The behavior of components in the DESs were deduced on the basis of thermal expansion coefficient (αP), apparent molar volume (V2∅), free volume (Fm), and spectroscopic analysis. The interactions in the DESs were further cross-checked by Quantum chemical calculation and molecular dynamics simulation. The consistent sequence of interaction strength in the DESs was TMU-KA > DMI-KA > DMPU-KA. For KA molecule, the hydroxyl H on ring displayed lower activity than that on the side-chain due to the dual impact of conjugation and volume repulsion effect. The obtained information can provide help for understanding structure-property relationship and exploring potential utilization for present KA/Urea DESs.

Thermodynamic and physicochemical characteristics of 2-butoxyethanol/2-phenoxyethanol in aqueous maltitol solutions

In this study, interactions occurring among solute and solvent in aqueous solutions containing maltitol and 2-butoxyethanol (2-BE) and 2-phenoxyethanol (2-PhE) as a solute were studied (Viz volumetric, acoustic and spectroscopic study). Density, ρ, and speed of sound,s, of 2-BE and 2-PhE in aqueous solutions of maltitol with concentrations (0.01, 0.02, and 0.03) mol∙kg-1 were measured at various temperatures ranging from 288.15 K to 308.15 K at 0.1 MPa.The data was used to calculate acoustic and thermodynamic parameters, such as the apparent molar volume (Vϕ), apparent molar isentropic compression (Kϕ,s), partial molar volume (Vϕ0) and partial molar isentropic compression at infinite dilution (Kϕ,s0). This analysis helped us understand the solvation behaviour of maltitol, which is a key component in sugar-free products. Additionally, the co-sphere overlap model was used to examine several intermolecular interactions in the ternary systems. We investigated the partial molar expansibilities (Eϕ0) and their first-order derivatives ∂Eϕ0/∂Tp to examine the solute's structure-making and structure-breaking properties. Finally, we also carried out spectroscopic studies for both binary and ternary mixtures. The observed molar properties indicate the presence of significant interactions between the solute and solvent components within the ternary mixture. This is further supported by the positive values of partial molar expansibility. Moreover, the partial molar properties of the mixture strongly imply the occurrence of hydrogen bond formation.

Thermodynamic and molecular simulation analysis of molecular interactions between methyl 2–hydroxyisobutyrate + water or n–alkanol (C1–C2) mixtures

Methyl 2–hydroxyisobutyrate (HBM) is essential as a photoresist thinner in semiconductor fabrication. In this study, we examined the density and viscosity of HBM combined with water or alkanol (C1–C2) at a pressure of 0.1 MPa and temperatures ranging from 288.15 K to 323.15 K. Based on experimental data, we calculated the excess molar volume, as well as apparent, partial, and excess partial molar volumes, and deviations in viscosity. These derived thermodynamic properties were then modeled using the Redlich-Kister (RK) polynomial equation. The VmE values of HBM + water mixtures are more negative compared to HBM + alkanol mixtures because of the stronger H–bonding interactions in HBM–water than in HBM–alkanol. With increasing temperature, the VmEbecome more negative, whereas the Δη values lower with a temperature rise. The values for excess molar volume and deviation in viscosity were analyzed through a graph theoretical method. Additionally, the excess free energy of activation was determined from the viscosity data. FTIR spectral analysis validated the findings related to intermolecular interactions and the graph theoretical method. Lastly, molecular dynamics simulations shed light on the intermolecular interaction energies and their differences in the studied binary systems.

Molecular interaction studies of antituberculosis drug Isoniazid in aq. β-cyclodextrin solution: A volumetric, spectroscopic and molecular docking approach

Volumetric and compressibility investigations are crucial to understanding the molecular interactions prevailing between various components of solutions. At distinct temperatures and ambient pressure (P = 0.1 MPa), the effect of β-cyclodextrin on the antituberculosis drug Isoniazid (INH) was studied at concentrations ranging from 0.0304-0.2698 mol.kg−1. Some thermodynamic properties of the drug Isoniazid, viz., limiting apparent molar volume and limiting compressibility (V°ϕ and K°S,ϕ) are derived from the appropriate density (ρ) and ultrasonic velocity (u) data, with experimental slopes Sv and Sk describing solute–solute interactional parameters at infinite dilution. Furthermore, transfer properties of drug, such as limiting transfer volume (ΔtrV°ϕ) and limiting transfer compressibility (Δtr K°S,ϕ) of drug, reveal key information regarding the interaction of drug with a solvent or a cosolute. The hydration number (nH) was computed to figure out the hydration behaviour of the studied drug in both the mediums. The encapsulation of isoniazid drug in the hydrophobic region of cosolute (β-cyclodextrin) in the solution phase was evaluated using 1H NMR titration. Additionally, theoretical molecular docking was employed to determine the possible conformation and binding energy of the non-covalent inclusion complex.

Volumetric and viscometric properties of L-glutamic acid in aqueous L-arabinose and D-xylose solutions between the temperature range of (293.15–313.15) K at atmospheric pressure

To investigate the molecular interaction among nonessential amino acids and carbohydrates in this article we report the density and viscosityresultsof L-glutamic acid in aqueous solutions of L-arabinose and D-xylose over an integral composition regime (2.00 wt%, 2.50 wt% and 3.01 wt%)at atmospheric pressure (101 kPa) and at temperature range of 293.15, 298.15, 303.15, 308.15 and 313.15 K. The experimental density values were used to evaluate apparent molal volume (V∅), partial apparent molal volume (V∅0), limiting apparent molal expansibility (E∅0) and Hepler’s constant (∂2V∅0/∂T2)P. The values of viscosity were used to calculate viscosity coefficients AF (Falkenhagen coefficients) and BJ (Jones-Dole coefficients), temperature derivative of BJ, Gibbs free energy of activation (Δμ10,#,Δμ20,#) and thermodynamic parameters like ΔH20# and ΔS20#. A thorough interpretation of the results obtained from the thermodynamic as well as physicochemical properties reveal a potent ion–solvent interactions in the aqueous solution of Glu andGlubehaves as a structure maker in the presence of L-arabinose/D-xylose.

Influence of anion structure on volumetric properties of dilute binary systems containing carboxylate functioned trihexylammonium ionic liquids in toluene / dodecane

We are actively involved in synthesis of hydrophobic ionic liquids, their volumetric behaviour in various solvents of different polarity and their application in metal ions extraction from water. In continuation of previous work, we are presenting new protic ionic liquids (PILs) containing Trihexylammonium cation and carboxylate anions namely Trihexylammonium propionate [THA][Pro] and Trihexylammonium pentanoate [THA] [Pent]. The simultaneous measurements of densities, ρ along with speeds of sound, u for binary systems of [THA][Pro] and [THA][Pent] in toluene and in dodecane were collected. The measurements were carried out in dilute concentrations range of PILs, at 0.1 MPa and different temperatures from 293.15 K to 328.15 K. The experimental values of densities, ρ and speeds of sound, u, were utilized to obtain calculated values of apparent molar properties: Vϕ (apparent molar volume) and Ks,ϕ (apparent molar isentropic compressibility). It is observed that the apparent molar properties of investigated systems are quite sensitive to variation in temperature, solvent and anion’s structure of PILs. The values of Vϕ and Ks,ϕ increases with each increment in studied temperature and when toluene was replaced by dodecane as a solvent in the system. The each addition of –CH2 group in anion chain of PILs leading to increase Vϕ whereas decrease with concentration of PILs in the binary system. The limiting values of apparent molar volume, Vϕ∞ and apparent molar isentropic compressibility, Kϕ∞ were also reported. The strength of interactions between PIL-PIL and PIL-solvent in studied binary systems was explained by Sk and Sv parameters. The PILs + dodecane systems exhibit greater interaction between PILs and solvent than binary systems of PIL + toluene.

Physicochemical studies of propylene and hexylene glycols in methanol solutions of hexachlorophene at different temperatures

The current study investigates the molecular interactions of glycol molecules (propylene (PG) and hexylene (HG) glycols) in hexachlorophene solutions at different temperatures and experimental pressure 0.1 MPa by merging acoustic and thermodynamic processes. The density and speed of sound of liquid mixtures are measured using an Anton Paar DSA 5000 M. These experimental values are used to calculate a variety of thermodynamic and acoustic parameters. The apparent molar volume (Vϕ), partial molar volume (Vϕ0), apparent molar isentropic compression (Kϕ,s), and partial molar isentropic compression (Kϕ,s0) are calculated with the help of experimentally determined density and speed of sound, as well as the partial molar expansibility (Eϕ0) is also calculated. The apparent molar parameters show the existence of strong interactions between solute and solvent in the ternary mixture, and it is also supported by the positive partial molar expansibility data, whereas the partial molar parameters indicate the hydrogen bonding formation in the mixture.

Comparative study on the environmental impact of Portland cement paste that mixed with naphthalene or carboxylate based polymer solutions

The environmental impact is now a valuable coefficient for any human activity. The effect of solar UV radiation on the cement samples was limited and contained in the thin surface layer of the samples. In general, viscocrete was the most effective in protecting cement against solar ultraviolet radiation, where cement samples treated with the two polymers used separately showed greater compressive strength values than those recorded for samples treated with sikament polymer. This study is important since the mechanical properties of cement and concrete at early stages are important in the field of civil engineering. The effect of soaking in water on the ability of the cement to withstand the pressure on it was also studied, and several physical measurements were applied to samples of untreated cement and samples mixed with the mentioned polymers. These measurements included measuring the porosity, density, and total dissolved solids by X-ray diffraction, FTIR, and line scan EDX. These measurements were carried out on cement samples before, after, after soaking in water, as well as on cement samples mixed with polymers. The measurements were extended to the soaking water. So, adding two types of polymers (Sikament and Viscocrete) separately to cement could protect concrete constructions against serious environmental impacts. The EDX analysis of the samples used in this study showed that the Egyptian sources of raw materials used in the cement industry are rich sources of rare chemical elements. The importance of adding two types of polymers, Sikament and ViscoCrete, separately to cement protects concrete construction against environmental impacts, which is our main highlight, significance, and advice of this work. Decrease the water reduction percentage and increase the compressive strength for portend cement paste to 0.5 % viscocrete using 15 W and 30 W UV lamps, with a maximum value of 127.52 MPa for 0.5 % viscocrete at the 30 W lamp. Higher UV lamp exposure at 45-watt lamp decreases the compressive strength after exposure than others. The total porosity percentage of all used percentages of Sikament polymer addition is greater than that using viscocrete polymer with a 0.75 % Sikament high value of 7.60 (total porosity) TP%. The conductivity EC of the cement treated with polymer samples shows a smaller increase in the case of viscocrete polymer than that of Sikament, with a value of 404 uS using 0.5 % and 0.75 % viscocrete, which is supported by TdS measurements with values of 202 ppm for 0.5 % and 0.75 % viscocrete, respectively. The EDX results for cement polymer mixtures prove that both polymers used extract many elements from the cement paste and protect human beings from their dangers, like Sb, Na, Zr, Hf, Rb, Mo., Ti, P, Cu, Er, Cl, In, and Te,Te with greater efficiency for the Viscocrete polymer than the Sikament one. Many factors affecting the cement's compressive strength and mechanical properties are the innovation of this work, which deals with the impact of some materials affecting it. The main target is to discuss the effect of different polymers on some properties of cement paste. Other properties can be discussed in near future, like the void volume effect, packing density, Van der Waals volume, and apparent molar volumes. The polymer contents have the largest effect on increasing the compressive strength of cement paste, followed by the w/c ratio and curing time.

Volumetric and viscometric properties of aqueous choline chloride + methyldiethanolamine deep eutectic solvents

Amine-based deep eutectic solvents have the advantages of easy preparation, extremely low vapor pressure, stable biodegradation and high CO2 loading, which has become the most potential CO2 absorbent. In this work, the amine-based functionalized DES of choline chloride + methyldiethanolamine with different molar ratios were successfully prepared, and the densities and viscosities of DES aqueous solutions were measured from 303.15 K to 333.15 K. The effects of DES composition, water content and temperature on the excess molar volume, partial molar volume, apparent molar volume, limiting partial molar volume and viscosity deviation were investigated. The hydration and intermolecular interaction in DES solution were analyzed. The critical concentration of water in solution was determined under the premise of maintaining DES hydrogen bond network.

Volumetric-acoustic study of Disodium Ethylenediaminetetraacetic acid with Propylene and Hexylene glycol at different temperatures

The present study shows the molecular interactions at constant pressure of 0.1 megapascals (MPa) and a range of temperatures from (288.15, 298.15, 308.15, 318.15 K) in aqueous solution of Disodium EDTA in (0.01, 0.02, 0.03) mol.kg-1 along with Propylene glycol and Hexylene glycol. Speed of sound and density data is determined using Anton Paar DSA 5000 M. Various thermo-acoustic parameters are calculated using the obtained data. Experimental density values determined apparent Molar Volume (Vϕ), Partial Molar Volume (Vϕ°) as well as Partial Molar Volume of Transfer (ΔVϕ°) along with Partial Molar Expansibility (Eϕ°) and thermal expansion coefficient (α). While speed of sound determined the Apparent Molar Isentropic Compression (Kϕ,S), Partial Molar Isentropic Compression (Kϕ,S°) as well as Partial Molar Isentropic Compression of Transfer (ΔKϕ.S°). Pair and Triplet Coefficients along with Empirical constants have also been estimated. FTIR spectroscopic research had been carried out in the binary mixture. From propylene through hexylene glycols, these factors provide data related to significant interactions between solute and solvent.

Influence of tetrabutylammonium bromide based ionic liquid on the aggregation behavior of dodecyltrimethylammonium bromide in the range (293.15 K–313.15 K): acoustic and volumetric investigation

Abstract The effect of the ionic liquid analogue tetrabutylammonium bromide on the aggregation behaviour of the cationic surfactant dodecyltrimethylammonium bromide in aqueous medium was investigated with volumetric and compressibility measurements over a wide temperature range (293.15–313.15) K. The data obtained were used to obtain density data. Based on the density data obtained, the volumetric properties (apparent molar volumes and partial molar volumes) of the surfactant in unimeric and micellar forms were evaluated and discussed in terms of the respective ionic and dipolar interactions. The data obtained were analysed to determine the effects of (i) temperature and (ii) salt added to the surfactant. The results were also interpreted in terms of the molecular interactions occurring in the binary mixtures of the present study. The addition of tetrabutylammonium bromide has a lowering effect on the CMC values of the surfactant studied in aqueous medium.