Ethyl Acetate Molecules Research Articles

Constructing Pd@Layered-CoOx/MFI Bifunctional Catalyst for Efficient Ethyl Acetate Oxidation: Boosted C═O Activation and *O Species Transformation.

Oxygenated volatile organic compounds (OVOCs), emitted in large quantities by the chemical industry, are a major contributor to the formation of ozone and subsequent particulate matter. For the efficient catalytic oxidation of OVOCs, the challenges of molecular activation and intermediate inhibition remain. The construction of bifunctional active sites with specific structures offers a promising way to overcome these problems. Here, the Pd@Layered-CoOx/MFI bifunctional catalyst with core-shell active sites was rationally fabricated though a two-step ligand pyrolysis method, which exhibits a superb oxidation efficiency toward ethyl acetate (EA). Over this, 13.4% of EA (1000 ppm) can be oxidized at just 140 °C with a reaction rate of 13.85 mmol·gPd-1·s-1, around 176.7 times higher than that of the conventional Pd-CoOx/MFI catalyst. The electronic coupling of the Pd-Co pair promotes the electron back-donation from Pd nanoparticles to the layered CoOx shell and facilitates the formation of Pd2+ species, which greatly enhances the adsorption and activation of the electron-rich C═O bond of the EA molecules. In addition, the synergy of these core-shell Pd@Layered-CoOx sites accelerates the activation and transformation of *O species, which inhibit the formation of acetaldehyde and ethanol byproducts, ensuring the rapid total oxidation of EA molecules via the Mars-van Krevelen mechanism. This work established a solid foundation for exploring robust bifunctional catalysts for deep OVOC purification.

Modulation of water reactivity by ethyl acetate/water co-solvent for zinc-metal batteries

The realization of durable aqueous zinc-metal batteries is hindered by uncontrollable Zn dendrite growth and serious parasitic reactions. Here, a miscible ethyl acetate (EA)/H2O co-solvent electrolyte is constructed by salting-in effect of Zn(OTf)2 to manipulate the solvation structures of Zn2+ and disrupt the original strong H-bond networks built by H2O. It reveals that EA molecules and OTf- jointly forms EA-H2O-OTf- co-dominated solvation sheath structure, weakening the coordination between Zn2+ and water molecules, meanwhile promoting Zn2+ immigration in reconstructed co-solvent H-bond environment. Besides, de-solvation water molecules with higher ionization barrier significantly inhibits H2O reactivity. Further, the introduced EA molecules are prone to preferentially adsorbed in Holmhertz Electrical Double Layers, which forms a hydrophobic interphase to regulate the uniform distribution of Zn2+ fluxes by steric structure. Therefore, it realizes dendrite-free zinc deposition with long plating/stripping stability of over 1300 h at 1 mA cm−2. In particular, the low temperature (600 cycles at −40 ℃) and ultra-long durable (20,000 cycles with 100 % capacity retention) electrochemical performance in Zn||Active Carbon zinc-ion capacitors, as well as long cycling stability (average coulombic efficiency of 99.91 % at 1 A g−1 after 1000 cycles) in Zn|| NaV3O8·1.5H2O batteries are also achieved.

Combining a Drug and a Nutraceutical: A New Cocrystal of Praziquantel and Curcumin

This study explores the co-crystallization between the drug praziquantel (PZQ) and the nutraceutical curcumin (CU). The investigation revealed two novel solid forms: a cocrystal solvate with ethyl acetate and a non-solvated cocrystal. This novel drug–nutraceutical cocrystal is a praziquantel–curcumin (2:1) cocrystal. The cocrystal solvate has ethyl acetate molecules occupying the voids with minimal interactions within the crystal lattice. The application of heat treatment induces solvent removal and prompts the transition to the non-solvated cocrystal, as highlighted by variable-temperature X-ray powder diffraction (VT-XRPD). Thermal analyses demonstrate the stability of the cocrystal solvate up to approximately 100 °C, beyond which it transforms into the non-solvated phase, which eventually melts at 130 °C.

How the spin state tunes the slow magnetic relaxation field dependence in spin crossover cobalt(II) complexes.

A novel family of cobalt(II) compounds with tridentate pyridine-2,6-diiminephenyl type ligands featuring electron-withdrawing substituents of general formula [Co(n-XPhPDI)2](ClO4)2·S [n-XPhPDI = 2,6-bis(N-n-halophenylformimidoyl)pyridine with n = 4 (1-3) and 3 (4); X = I (1), Br (2 and 4) and Cl (3); S = MeCN (1 and 2) and EtOAc (3)] has been synthesised and characterised by single-crystal X-ray diffraction, electron paramagnetic resonance, and static (dc) and dynamic (ac) magnetic measurements combined with theoretical calculations. The structures of 1-4 consist of mononuclear bis(chelating) cobalt(II) complex cations, [CoII(n-XPhPDI)2]2+, perchlorate anions, and acetonitrile (1 and 2) or ethyl acetate (3) molecules of crystallisation. This unique series of mononuclear six-coordinate octahedral cobalt(II) complexes displays both thermally-induced low-spin (LS)/high-spin (HS) transition and field-induced slow magnetic relaxation in both LS and HS states. A complete LS ↔ HS transition occurs for 1 and 2, while it is incomplete for 4, one-third of the complexes being HS at low temperatures. In contrast, 3 remains HS in all the temperature range. 1 and 2 show dual spin relaxation dynamics under the presence of an applied dc magnetic field (Hdc), with the occurrence of faster- (FR) and slower-relaxing (SR) processes at lower (Hdc = 1.0 kOe) and higher fields (Hdc = 2.5 kOe), respectively. On the contrary, 3 and 4 exhibit only SR and FR relaxations, regardless of Hdc. Overall, the distinct field-dependence of the single-molecule magnet (SMM) behaviour along with this family of spin-crossover (SCO) cobalt(II)-n-XPhPDI complexes is dominated by Raman mechanisms and, occasionally, with additional temperature-independent Intra-Kramer [LS or HS (D > 0)] or Quantum Tunneling of Magnetisation mechanisms [HS (D < 0)] also contributing.

Synthesis of carbonyl compounds dibenzo-18- crown-6 by the Grinard reaction

In this article, Grignard reactions of 4´,4´´-diiododibenzo-18- crown-6 were carried out to obtain carbonyl compounds in an inert argon atmosphere. An aldehyde, 4´,4´´-diformyldiioddibenzo-18-crown-6, and a ketone, 4´,4´´-diacetyldibenzo-18-crown-6, were obtained. The reactivity and geometry of ethyl acetate, acetic anhydride, and acetic acid chloride molecules were analyzed, which was reflected in the difference in the yields of the target product: ester (22%) &lt;anhydride (37%) &lt;acid chloride (48%). It was determined that tertiary alcohols and various oxidation products are by-products of the reaction. A quantum-chemical calculation and comparison of the spectra of carbonyl compounds, diacetyldibenzo-18- crown-6 were performed. The obtained compounds were identified using 1H-13C-NMR and IR spectroscopy.

The Perspective of Using the System Ethanol-Ethyl Acetate in a Liquid Organic Hydrogen Carrier (LOHC) Cycle

Starting from bioethanol it is possible, by using an appropriate catalyst, to produce ethyl acetate in a single reaction step and pure hydrogen as a by-product. Two molecules of hydrogen can be obtained for each molecule of ethyl acetate produced. The mentioned reaction is reversible, therefore, it is possible to hydrogenate ethyl acetate to reobtain ethanol, so closing the chemical cycle of a Liquid Organic Hydrogen Carrier (LOHC) process. In other words, bioethanol can be conveniently used as a hydrogen carrier. Many papers have been published in the literature dealing with both the ethanol dehydrogenation and the ethyl acetate hydrogenation to ethanol so demonstrating the feasibility of this process. In this review all the aspects of the entire LOHC cycle are considered and discussed. We examined in particular: the most convenient catalysts for the two main reactions, the best operative conditions, the kinetics of all the reactions involved in the process, the scaling up of both ethanol dehydrogenation and ethyl acetate hydrogenation from the laboratory to industrial plant, the techno-economic aspects of the process and the perspective for improvements. In particular, the use of bioethanol in a LOHC process has three main advantages: (1) the hydrogen carrier is a renewable resource; (2) ethanol and ethyl acetate are both green products benign for both the environment and human safety; (3) the processes of hydrogenation and dehydrogenation occur in relatively mild operative conditions of temperature and pressure and with high energetic efficiency. The main disadvantage with respect to other more conventional LOHC systems is the relatively low hydrogen storage density.

Recyclable Co3O4/NaF for hydrogen generation from ethyl acetate: The promoting effect between Co3O4 and NaF

Secondary reforming of oxygenated organic compounds is the key to opening up the industrial chain of hydrogen production from organic matter. In this work, a low-cost and high-efficiency Co3O4/NaF catalyst with recyclable re-preparation was developed to solve the application bottleneck that existing commercial reforming catalysts were expensive and difficult to recycle after deactivation and discarded. Ethyl acetate was selected as the representative oxygenated organic compound for hydrogen generation via autothermal reforming was studied. The results showed that the Co3O4/NaF catalysts efficiently produced hydrogen from ethyl acetate, and the 7.5 %-Co3O4/NaF catalyst achieved 82.7 % hydrogen yield at 600 °C, 100 % ethyl acetate conversion and 16 h running stability. And the used catalyst after once recyclable re-preparation is restored to the initial hydrogen production level of fresh catalyst. Combined with XRD, N2 adsorption/desorption, FE-SEM, H2-TPR and in situ DRIFTS analysis, it was found that the surface micro-structure of the Co3O4/NaF catalyst was dense, and its specific surface area was ultra-small less than 0.5 m2·g−1, which broke through the limitation that low specific surface catalyst was difficult to obtain high-mass catalytic activity. The hydrogen production from ethyl acetate via autothermal reforming over the Co3O4/NaF catalyst was a rapid surface reaction. In addition, DFT calculations confirmed that NaF could effectively adsorb ethyl acetate molecule with an adsorption energy of −0.438 eV/molecule, and the combination of Co3O4 and NaF promoted more efficient adsorption of ethyl acetate molecules by Co3O4/NaF, with an adsorption energy of −0.836 eV/molecule. The F atom in NaF can induce electrons migration from the Co atom in Co3O4 to the F atom, which improved the redox properties and hydrogen production activity of the Co3O4/NaF catalyst.

Improving Solubility and Avoiding Hygroscopicity of Tetrahydropalmatine by Forming a Pharmaceutical Salt Cocrystal via CAHBs

AbstractIn order to improve the solubility of tetrahydropalmatine (THP), an unreported THP‐sulfosalicylic acid (THP‐SSA) pharmaceutical salt cocrystal is designed and synthesized. Structural analysis shows that the building unit of THP‐SSA is composed of two THP cations, two SSA anions and one ethyl acetate molecule. Meanwhile, 1D chain, 2D layered structure, 3D hydrogen bond network, and Supramolecular motif R1110(48) of THP‐SSA are connected by stable charge‐assisted hydrogen bonds (CAHBs) N+‐H···O‐, π–π packing, and hydrogen bond. As expected, the maximum solubility of THP‐SSA in water is about 60 times that of THP, probably due to the protonation of the N atom on the piperidine ring in THP forms a pharmaceutical salt cocrystal, which greatly improves the solubility of THP. However, to the surprise, the hygroscopicity of THP‐SSA is also effectively reduced compared with THP, probably because the hydrogen bonds between THP and SSA have been formed, preventing the entry of water molecules. In addition, THP‐SSA also has higher antibacterial activity than THP. This suggests that forming a pharmaceutical salt cocrystal by cocrystal technology can not only improve the solubility of THP and avoid the hygroscopic property, but also improve the antibacterial activity of THP in vitro.

δ-antimonene nanosheet as a sensing element for ethyl acetate and butyl acetate – a first-principles study

The detection of volatile organic compounds, such as ethyl acetate, and butyl acetate emitted from industries is essential to ensure safety. The two-dimensional (2D) material δ-antimonene nanosheet (δ-SbNS) is used as a base substrate for the detection of ethyl acetate, and butyl acetate vapours. Based on the first-principles investigation, the structural stability and electronic properties of δ-SbNS are determined. The adsorption energy indicates that ethyl acetate and butyl acetate molecules are physisorbed on δ-SbNS. Furthermore, the electron difference density and charge transfer studies reveal the acceptor nature of δ-SbNS. Also, the projected density of states (PDOS) and energy band structure studies upon adsorption of ethyl acetate, and butyl acetate on δ-SbNS are reported. The δ-SbNS behaves as a chemi-resistor owing to adsorption and desorption of ethyl acetate, and butyl acetate vapours.

Sensing response of novel ε-antimonene nanosheet towards ethyl acetate and isopropyl acetate – A DFT insight

We deployed ε-antimonene nanosheet (ε-SbNS) as a chemical sensor to sense ethyl acetate (EA) and isopropyl acetate (IPA) molecules at ambient conditions. At first, the structural firmness of ε-SbNS is validated with the support of formation energy, phonon band spectrum, and elastic constants. Further, the electronic properties of the ε-SbNS are conversed using the projected density of states (PDOS) and band structure. The band gap value of ε-SbNS is calculated to be 0.461 eV. Importantly, the adsorption behaviour of chief EA and IPA molecules is studied by determining parameters Bader charge transfer, adsorption energy, and relative energy gap variation. The range of adsorption energy (−0.026 eV to −0.283 eV) reveals that the EA and IPA are physisorbed on ε-SbNS. The findings suggested that ε-SbNS can be employed as a chemical sensor to detect the acetate ester molecules emitted from paint and varnish industries.

Crystal structure of fulvestrant hydrate (ethyl acetate), C32H47F5O3S(H2O)0.16(C4H8O2)0.025

The crystal structure of fulvestrant hydrate (ethyl acetate) has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. This solvate of fulvestrant crystallizes in space group R3 (#146) with a = 23.39188(16), c = 16.50885(13) Å, V = 7823.08(7) Å3, and Z = 9. The crystal structure is composed of triangular hydrogen-bonded chains of molecules around one of the threefold axes. The fluorinated ends of the molecules cluster around another threefold axis. Voids around a threefold axis occupy 8.1% of the unit cell volume, and are partially occupied by the water and ethyl acetate molecules. Both hydroxyl groups act as donors in O–H⋯O hydrogen bonds. These H-bonds form a large ring. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).

Hierarchical core-shell heterostructures of α-MoO3 nanorods@NiO nanosheets for significant detection of ethyl acetate vapor

Ethyl acetate (EA), can be served as an important marker to evaluate the freshness of many fruits. However, it is still a limiting factor to efficiently detect it due to the low chemical reactivity and complex interferences. Herein, a hierarchical one-dimenstional (1D) heterostructure consisting of the α-MoO3 nanorods (core) and NiO nanosheets (shell) has been successfully demonstrated by a facile hydrothermal and followed annealing route. This hierarchical core-shell heterojuction integrates the structural merits and synergistic catalytic activity of two transition metal oxide (α-MoO3 and NiO). As an outcome, this α-MoO3 @NiO product shows a significant response towards EA vapor in terms of high response, impressive selectivity, and low detection limit (~148 ppb). Moreover, the in-situ DRIFTS results reveal the possible intermediates (acetyl and acetate) in this EA-sensing event. Meanwhile, the enhancement in EA-sensing is also discussed from the aspects of strong adsorption of EA molecules onto the surfaces, n-p heterojunction between the α-MoO3 nanorods and NiO nanosheets, as well as increase of specific surface area and surface chemisorbed oxygen. This work sheds a new hierarchical core-shell heterojuction for detection of low reactive vapor in complex surroundings.

Nisoldipine in Several Aqueous and Non-Aqueous Cosolvent Solutions: Solubility Modeling and Preferential Solvation Research

The study mainly reported the equilibrated solubilities of nisoldipine in aqueous solutions of n-propanol/acetonitrile + water and non-aqueous solutions of ethyl acetate + ethanol/isopropanol by dint of experimentation and model correlations. Solubility was experimented via the shake-flask method under 101.2 kPa from 278.15 to 318.15 K. The maximum of nisoldipine solubility (in mole fraction unit) was found in neat n-propanol/acetonitrile/ethyl acetate at 318.15 K, and the minimum was found in neat water/isopropanol/ethanol. The total and three-dimensional Hansen solubility parameters were employed herein to explain the solubility behavior of nisoldipine. Modeling solubility through mixture response surface, Jouyban–Acree, and Jouyban–Acree–van’t Hoff models resulted in relative average deviations of <10.3%. Quantitative research upon preferential solvation was carried out by applying the approach of inverse Kirkwood–Buff integrals for the four solution systems considered in the present study and two aqueous solutions of ethanol/isopropanol reported in the literature. The local fractions of n-propanol/acetonitrile/ethanol/isopropanol for the four aqueous solutions as well as ethyl acetate for non-aqueous solution of ethyl acetate + isopropanol were greater than that of bulk ones in n-propanol/acetonitrile/ethanol/isopropanol/ethyl acetate-rich and middle composition proportions, demonstrating that the solvation of nisoldipine was preferred by cosolvents (n-propanol/acetonitrile/ethanol/isopropanol/ethyl acetate). It is able to speculate that nisoldipine displays Lewis acid behavior in these regions with the cosolvent molecules in aqueous solution systems and with the ethyl acetate molecules or isopropanol in the ethyl acetate + isopropanol solution system.

Insight into the deactivation mechanism of water on active Cu species for ester hydrogenation: Experimental and theoretical study

Water is inevitably existed in the industrial production and counted as a critical issue; however, the effect of water on Cu/SiO2 catalysts was often ignored and the relation between of water and deactivation mechanism in the hydrogenation reaction is rarely studied. In this work, the effect of water on ester hydrogenation was investigated experimentally and theoretically. The hydrogenation of ethyl acetate was chosen as probe reaction and the reagent containing water was used to simulate industrial feedstock. The obtained experimental results of the hydrogenation and the in-situ DRIFT and DFT calculation have demonstrated that the presence of water is hardly affected ethanol selectivity but decreased the catalytic activity. The main reason for the showed catalyst deactivation is the competitive adsorption (reversible) mechanism of water and ethyl acetate molecules. More precisely, the active species of Cu+ surface is preferred the adsorption of H2O over ethyl acetate molecule consequently leads to a rapidly decreasing in the conversion ratio of ethyl acetate. Although the adsorption of water molecule is only occupied the Cu+ sites in the catalyst and could also release at reaction temperature, the conversion was partially recovered due to the growth, leaching and oxidation of copper species caused by water when water was removed.

Fast Chemo‐Responsive Shape Memory of Stretchable Polymer Nanocomposite Aerogels Fabricated by One‐Step Method

AbstractA new type of stretchable poly(caprolactone)/graphene oxide (PCL/GO) aerogel with fast chemo‐responsive shape memory effect is fabricated by one‐step method of a sol‐gel procedure. The PCL/GO aerogels show uniformly circular and interconnected pores formed by twisted PCL nanolayers. GO platelets improve the crystallinity of PCL and increase the fracture stress and strain by 150% and 300% respectively, although the GO loading is only 0.5%. The dramatic increment of break strain is attributed to the uniform and circular pores that can afford large deformation and the interaction of GO and PCL. The aerogels can be programmed by external stress at ambient temperature without heating and recover upon ethyl acetate (EA) in 1 s. The fast chemo‐responsive shape recovery is ascribed to the fast wrinkle of the PCL nanolayers that decrease the diffusion time greatly and the interconnected micrometer pores that are in favor of penetrating for EA molecules.

Molecular dynamics investigation on the morphology of HNIW affected by the growth condition

ABSTRACTThe crystal morphology of Hexanitrohexaazaisowurtzitane (HNIW) in vacuum and ethyl acetate was investigated by attachment energy (AE) model through molecular dynamics (MD). The simulated solvent-affected outcome agrees well with the experimental crystal habit cultivated from ethyl acetate. The influence of model size on the modified AE was discussed, and a reasonable model size was obtained. The model size can be broadened to calculate the morphology of other compounds. The radial distribution function (RDF) analyses and diffusion coefficient analyses were performed to explore the adsorption and diffusion behaviors of ethyl acetate molecules on HNIW surfaces. The simulation results can provide some guidance for the further crystallization process of HNIW.

Mixed lanthanide coordination polymers for temperature sensing and enhanced NdIII NIR luminescence

Three LnIII coordination polymers, [Ln2L3(NO3)3]n·2CH3COOCH2CH3 (Ln = Nd (Nd2L3), Eu (Eu2L3), Tb (Tb2L3)), following coordination-assembly reactions involving a new bi-monodentate salicylamide ligand, L = 1,4-bis[(2΄-thenylaminoformyl)phenoxyl]methyl}-benzene, have been successfully synthesized. Among them, Nd2L3 and Tb2L3 were structurally authenticated by single-crystal X-ray diffraction and the results indicate both Nd2L3 and Tb2L3 are one-dimensional corrugated blockchains with LnIII containing 64-membered block loops filled by ethyl acetate molecules alternating in nearly orthogonal directions. For they are isomorphous, two binary co-doped lanthanide coordination polymers, Tb0.965Eu1.035L3 and Tb0.717Nd1.283L3 are obtained. Luminescent studies indicate that Tb0.965Eu1.035L3 exhibits a temperature recognition property with the significantly high sensitivity of 2.61% per K in the 296–386 K temperature range upon excitation at 345 nm as well as white emission when excited in the range of 370–390 nm. Tb0.717Nd1.283L3 shows enhanced NdIII-centred NIR luminescence and diminished TbIII-centred luminescence as compared to those of Nd2L3 and Tb2L3. The results presented herein show that the energy transfer from TbIII to both EuIII and NdIII has been successfully achieved in Tb0.965Eu1.035L3 and Tb0.717Nd1.283L3. Generally speaking, this work explores the potential applications of lanthanide-based coordination polymers based on multi-monodentate salicylamide ligand in the area of thermal sensing.

Fabrication of biomass-derived C-doped Bi2WO6 templated from wood fibers and its excellent sensing of the gases containing carbonyl groups

In this work, wood fibers (Populus ussuriensis Kom) were used as biotemplate to synthesize Bi2WO6. In corporation of biomass-derived C, the sensitivity to the gases containing carbonyl groups of gas sensors is improved. The experimental results showed that the C-doped Bi2WO6 sensors presented high sensitivities to acetone, acetic acid and ethyl acetate molecules at low temperature (370°C). The gas sensitivities of C-doped Bi2WO6 sensors on exposure to 1000ppm of acetone, acetic acid and ethyl acetate gas are 4.4, 3.0 and 2.4 times higher than that exposure to 1000ppm of ethanol, respectively. That is because the biomass-derived C can adsorb more oxygen molecules and the carbonyl groups in the gases can react with more oxygen molecules and release more electrons leading a resistance decrease of the sensors due to the electronic structure of carbonyl groups. The reported strategy opened up a new way for the development of gas sensors.

Monte Carlo simulations of vapour–liquid phase equilibrium and microstructure for the system containing azeotropes

Phase equilibrium data of the mixtures including alcohols, esters and organic acids are of first interest particularly to design and optimise biodiesel production and reactive distillation processes. In this work, vapour–liquid phase equilibrium of these systems was simulated at low pressure using Gibbs ensemble Monte Carlo method. All Lennard–Jones parameters of pseudo-atoms involved in the systems were derived from previous parametrisations of TraPPE-UA force field. The Fourier coefficients of dihedrals encountered in ethyl acetate molecule have been obtained from the quantum calculations. Using this force field, temperature-composition diagrams are well reproduced for ethyl acetate + ethanol, ethyl acetate + methanol at 70.00 kPa and ethyl acetate + acetic acid mixtures at 77.33 kPa. The transferability of this force field to mixtures in these systems is noticeable. Analysis of the microstructure for the ethyl acetate + ethanol and ethyl acetate + acetic acid mixtures was presented. We found that the hydrogen bond networks consist of autoassociation and cross-association and autoassociation occupies the main position as compared with cross association in the ethyl acetate + ethanol mixture. OCHAc–HHAc and OCEtOAc–HHAc hydrogen bond interactions play a significant role in the phase behaviours or structures of ethyl acetate + acetic acid mixture.

Preferential solvation of dehydroepiandrosterone acetate in (co-solvent + ethyl acetate) mixtures according to the inverse Kirkwood–Buff integrals method

The preferential solvation parameters (δx1,3) of dehydroepiandrosterone acetate (DHEA acetate) in three co-solvent mixtures of methanol (1)+ethyl acetate (2), ethanol (1)+ethyl acetate (2), and isopropanol (1)+ethyl acetate (2) were derived from their available solubility data by means of the inverse Kirkwood–Buff integrals method. The values of δx1,3 vary non-linearly with the co-solvent (1) proportion in all the co-solvent mixtures. For the studied systems, the values of δx1,3 are negative in alcohol-rich mixtures, but positive in ethyl acetate-rich mixtures. The preferential solvation magnitude of DHEA acetate by the ethyl acetate is highest in {methanol (1)+ethyl acetate (2)} mixtures at 293.15K and 303.15K. While at 313.15K, it is highest in {isopropanol (1)+ethyl acetate (2)} mixtures. The δx1,3 values are positive indicating that DHEA acetate is preferentially solvated by ethyl acetate. The co-solvent action may be related to the disordered structure of ethyl acetate molecules around the non-polar moieties of DHEA acetate which increases the solvation having maximum values near to x1=0.25–0.35 for the three co-solvent mixtures.