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Numerical simulations of silicone oil–water two-phase turbulent dispersion mixing in Q-type static mixers (QSM) are performed using computational fluid dynamics (CFD) coupled with a population bala...

While many studies have investigated synergic interactions between surfactants in mixed systems, understanding possible competitive behaviors between interfacial components of binary surfactant systems is necessary for the optimized efficacy of applications dependent on surface properties. Such is the focus of these studies in which the surface behavior of a binary surfactant mixture containing nonionic (Span-80) and anionic (AOT) components adsorbing to the oil/water interface was investigated with vibrational sum-frequency (VSF) spectroscopy and surface tensiometry experimental methods. Time-dependent spectroscopic studies reveal that while both nonionic and anionic surfactants initially adsorb to the interface, anionic surfactants desorb over time as the nonionic surfactant continues to adsorb. Concentration studies that vary the ratio of Span-80 to AOT in bulk solution show that the nonionic surfactant preferentially adsorbs to the oil/water interface over the anionic surfactant. These studies have important implications for applications in which mixed surfactant systems are used to alter interfacial properties, such as pharmaceuticals, industrial films, and environmental remediation.

Exploiting new interface-active solid catalysts is crucial to construct efficient Pickering emulsion systems for biphasic catalysis. In this work, ultrathin g-C3N4 nanosheets (g-C3N4-NSs) were developed as a new solid emulsifier to directly position catalytic sites at oil-water interfaces for improving the reaction efficiency of a biphasic reaction. Exemplified by a metal-involved biphasic reaction of nitroarenes reduction, the developed Pd/g-C3N4-NSs catalyst with Pd nanoparticles loaded on the surface of g-C3N4-NSs exhibited excellent activity with a catalytic efficiency of 1220 h-1. Such activity was 4.2 and 17.9 times higher than those of Pd/g-C3N4-bulk and the ordinary Pd/C8-SiO2 catalyst, respectively. Also, in the biphasic oxidation reaction of alcohols, Pd/g-C3N4-NSs achieved a 2.3-fold activity enhancement. It was found by analyzing the solidified emulsion droplets that the Pd/g-C3N4-NSs catalyst was parallelly assembled at the oil-water interfaces. Because of the ultrathin thickness of g-C3N4-NSs, such a unique interfacial assembly behavior allowed precise positioning of Pd nanoparticles at the oil-water interfaces. As a result, the oil-soluble reactant could directly react with the water-soluble reactant at the oil-water interface hosting the Pd nanoparticles. Our elaborately designed reaction interface was believed to substantially avoid the diffusion barrier between oil-soluble and water-soluble reactants and then to significantly enhance the reactivity of biphasic reactions. This work highlights the importance of the interfacial location of catalytic sites in biphasic catalysis.

Made available in DSpace on 2022-04-28T19:42:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-08-12 This paper reports experimental results and thermodynamic modeling of the liquid-liquid equilibrium (LLE) of the system chicha biodiesel (Sterculia striata) + glycerol + ethanol. Binodal curves and tie lines were obtained at different temperatures (303.15, 318.15, and 333.15 K) and atmospheric pressure (101.3 kPa). The quality of the experimental data was evaluated using the criteria of Marcilla and co-workers. The nonrandom two-liquid (NRTL) and analytical solutions of groups (ASOG) models were used to correlate the LLE data. Both models well fitted the experimental data with root-mean-square deviations (rmsd) not greater than 1.5%. Laboratory of Separation Systems and Process Optimization (LASSOP) Center of Technology Federal University of Alagoas, Alagoas Department of Chemical Engineering Federal University of Parana, Paraná Engineering School of Lorena Department of Chemical Engineering University of Sao Paulo (USP), São Paulo Department of Energy Engineering Sao Paulo State University (UNESP), São Paulo Department of Energy Engineering Sao Paulo State University (UNESP), São Paulo

Biomolecular condensates comprised of specific proteins and nucleic acids are now recognized as one of the key organizing mechanisms in eukaryotic cells. However, the specific roles played by the nucleic acid secondary structure and sequence in biomolecular phase separation are still not clear. Here, utilizing giant membrane vesicles (GMVs) as a protocell model, we found that single-stranded DNA (ssDNA) with a parallel G-quadruplex structure could functionally cooperate with a G-quadruplex-binding protein to form speckle-like puncta inside the GMVs. The clustering behavior is dependent on the structural diversity of G-quadruplexes, and the reversible clustering behavior implicated a new pathway in dynamically regulating the formation of biomolecular condensates. This finding represents a potential link between G-quadruplex-binding proteins and the resulting G-quadruplex-mediated biomolecular phase separation, which would gain insight into a wide range of biological processes associated with nucleic acid-modulated phase separation inside living cells.

The stories behind supercooled bulk and confined water can be different. Bulk water has a metastable liquid-liquid phase transition at deeply supercooled conditions, but the existence of such a phenomenon in confined water is in question. Herein we show simulation results of first-order phase transitions between high- and low-density liquid (HDL and LDL) in confined water in both positive and negative pressures. A mid-density state between these two local states appears, which lets the transition show the hysteresis loop with transiently stable intermediate states. On the basis of Landau theory that we have adapted for mixing of moieties with high- and low-density states, we explain the phase transitions with the order parameter-dependent free energy change which is governed by second- to higher-order interactions among those moieties.

The phase behavior of atmospheric aerosol particles influences processes like gas-particle partitioning, solar light scattering, and cloud formation, ultimately affecting atmospheric air quality an...

Phase equilibria of the ternary system (water + phosphoric acid + mesityl oxide) were investigated, and experimental tie-line data of liquid–liquid equilibrium were obtained at T = (298.2, 308.2, a...

Liquid–liquid equilibrium (LLE) data for the ternary mixture of water + 2,2,3,3-tetrafluoro-1-propanol (TFP) + {1-pentanol or 2-ethyl-1-hexanol or n-propyl acetate or dichloromethane} was measured ...

In this study, the temperature effect on the aqueous two-phase systems composed of isopropanol + trisodium citrate + water was studied by experimental measurement of the binodal curves and tie-line...

To obtain the basic data for the recovery of 1-methylimidazole from wastewater by extraction, the ternary liquid–liquid phase equilibrium data of the water (1) + 1-methylimidazole (2) + 1-butyl-3-m...

Wastewater containing DMF (N,N-dimethylformamide) and salt is generated in production of many chemicals and medicines. The composition of phase equilibrium should be known primarily for the recover...

For separating 2-butanone and water from the azeotropic system, the liquid–liquid equilibria (LLE) data for the ternary mixture of solvents (p-xylene, mesityl oxide) + 2-butanone + water at 298.2, ...

Liquid–liquid equilibria in the H2O–HNO3–Eu(NO3)3–Gd(NO3)3–tributyl phosphate (TBP) system and in two H2O–HNO3–Ln(NO3)3–TBP (Ln = Eu, Gd) subsystems have been investigated at 298.15 K in a wide ran...

The effects of various structural and operating parameters on liquid–liquid dispersion and selectivity of chemical reactions in inline single-row teethed high shear mixers (HSMs) were studied by a ...

Liquid-liquid phase separation (LLPS) is involved in both physiological and pathological processes. The intrinsically disordered protein Tau and its K18 construct can undergo LLPS in a distinct temperature-dependent manner, and the LLPS of Tau protein can initiate Tau aggregation. However, the underlying mechanism driving Tau LLPS remains largely elusive. To understand the temperature-dependent LLPS behavior of Tau at the monomeric level, we explored the conformational ensemble of Tau at different temperatures by performing all-atom replica-exchange molecular dynamic simulation on K18 monomer with an accumulated simulation time of 26.4 μs. Our simulation demonstrates that the compactness, β-structure propensity, and intramolecular interaction of K18 monomer exhibit nonlinear temperature-dependent behavior. 295DNIKHV300/326GNIHHK331/337VEVKSE342 make significant contributions to the temperature dependence of the β propensity of K18 monomer, while the two fibril-nucleating cores display relatively high β propensity at all temperatures. At a specific temperature, K18 monomer adopts the most collapsed state with exposed sites for both persistent and transient interactions. Given that more collapsed polypeptide chains were reported to be more prone to phase separate, our results suggest that K18 monomer inherently possesses conformational characteristics favoring LLPS. Our simulation predicts the importance of 295DNIKHV300/326GNIHHK331/337VEVKSE342 to the temperature-dependent conformational properties of K18, which is corroborated by CD spectra, turbidity assays, and DIC microscopy. Taken together, we offer a computational and experimental approach to comprehend the structural basis for LLPS by amyloidal building blocks.

We report on the dynamic response of aqueous solution containing poly(N-isopropylacrylamide)-capped gold (pNIPAM-capped Au) nanoparticles to the introduction of NaCl. The addition of NaCl increases...

Compositions of coexisting phases (liquid–liquid equilibrium), solubility, and critical states for the quaternary acetic acid–n-butyl alcohol–n-butyl acetate–water system were carried out at 328.15...

In the field of industrial crystallization, liquid–liquid phase separation (LLPS) easily makes the crystallization process into an uncontrollable state, making it extremely difficult for people to ...

2,2-Difluoroethanol (DFE) is an important aliphatic fluorine-containing chemical intermediate. During its preparation, an azeotropic mixture of DFE and water is formed. To recover DFE from its aque...

The adsorption of two-dimensional (2-D) graphene oxide (GO) nanosheets at liquid-liquid interfaces has broad technological implications from functional material preparations to oil-water emulsification. Molecular-level understanding of the adsorption thermodynamics and the interfacial behavior is of great significance. Here, the adsorption free energy of GO nanosheets at the water-cyclohexane system was simulated, in which the effect of oxygen-containing groups and deprotonation has been investigated. It was observed that the neutral GO (GO-COOH) has obvious interfacial activity with a reduction of interfacial tension, while the deprotonated GO (GO-COO-) shows a weak interface affinity. There exists an optimal oxidization degree that could cause the best interfacial stability, which is attributed to the balance of interfacial hydrophilic-hydrophobic interactions. The interaction arising from water is the main factor determining interfacial activity. The interfacial morphology and dynamics of GO nanosheets have also been simulated, in which an anisotropic 2-D translation and rotation along the interface were revealed. Our simulation results provide new insight into the adsorption mechanism and dynamics behavior of GO at the oil-water interface.

In the present study, liquid–liquid flow dynamics are compared in three different geometries experimentally. These are straight glass capillary, serpentine geometry made of glass capillary, and ser...

Intrinsically disordered proteins (IDPs) populate an ensemble of dynamic conformations, making their structural characterization by experiments challenging. Many IDPs undergo liquid-liquid phase separation into dense membraneless organelles with myriad cellular functions. Multivalent interactions in low-complexity IDPs promote the formation of these subcellular coacervates. While solution NMR, Förster resonance energy transfer (FRET), and small-angle X-ray scattering (SAXS) studies on IDPs have their own challenges, recent computational methods draw a rational trade-off to characterize the driving forces underlying phase separation. In this Perspective, we critically evaluate the scope of approximation-free field theoretic simulations, well-tempered ensemble methods, enhanced sampling techniques, coarse-grained force fields, and slab simulation approaches to offer an improved understanding of phase separation. A synergy between simulation length scale and model resolution would reduce the existing caveats and enable theories of polymer physics to elucidate finer details of liquid-liquid phase separation (LLPS). These computational advances offer promise for rigorous characterization of the IDP proteome and designing peptides with tunable material and self-assembly properties.

The approach coupling computational fluid dynamics and a population balance model (PBM) was adopted to simulate the hydraulic performance of liquid–liquid dispersions in a pump-mixer. Behaviors of ...

Liquid–liquid equilibrium data were obtained for aqueous two-phase system (ATPS) composed of [poly(ethylene oxide) (PEO1500), poly(propylene oxide) (PPO425), poly(ethylene oxide)11–poly(propylene o...

In this study, four ternary liquid–liquid equilibrium systems containing a solvent, furfural, and water were investigated by performing liquid–liquid equilibrium measurements at two different tempe...

From the liquid–liquid equilibrium (LLE) data of a linear polymer, an investigation of the Sanchez and Lacombe equation of state (SL-EOS) is performed with the goal of describing the swelling of th...

The ternary liquid–liquid equilibrium (LLE) data for cyclohexanone (CYC) + phenol + water were determined at T = (298.15, 313.15, and 323.15) K and atmospheric pressure. The distribution coefficien...

This work comprises the separation of an azeotropic mixture (hexane/ethyl acetate) with two different ionic liquids, viz, (1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF4], and 1-ethyl-3-...

In this article, Aspen Plus was used to simulate a process for separating the mixture of decanol + undecanol + tetradecane + pentadecane to obtain decanol + undecanol product and tetradecane + pent...

The separation of cyclopentanone from aqueous solutions with recommended (propan-2-yl) benzene (cumene) solvent was investigated at different temperatures of 293.2, 298.2, and 308.2 K and with the ...

The synergistic extraction of phenol from aqueous solution with diisopropyl ether (DIPE) and n-pentanol was studied at 298.15 K under 101.3 kPa. The liquid–liquid equilibrium (LLE) data of the quat...

Ternary liquid–liquid equilibrium (LLE) data were measured for the {water + phosphoric acid + aromatic esters (benzyl acetate, benzyl benzoate, dimethyl phthalate, and diethyl phthalate)} systems a...

Liquid–liquid equilibrium (LLE) and solubility for the quaternary acetic acid–n-propyl alcohol–n-propyl acetate–water were carried out at 323.15 and 333.15 K (atmospheric pressure). A brief review ...