Excess molar enthalpies of the ternary mixtures: Methyl tert‐butyl ether (or di‐isopropyl ether) + n‐octane + 2‐methylpentane at 293.15 K

Microcalorimetric measurements of excess molar enthalpies at 298.15 K are reported for the two ternary mixtures, methyl tert‐butyl ether (MTBE) or di‐isopropyl ether (DIPE) + n‐octane + 2‐methylpentane (2‐MP). The excess enthalpies for DIPE + 2‐MP are also reported. Smooth representations of the ternary enthalpies results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. It is shown that good estimates of the ternary enthalpies can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures.     

Density,refractive index,excess molar volumes and deviations in molar refraction at 298.15 K for binary and ternary mixtures of DIPE (OR TAME) + 1‐methanol (or 1‐propanol) + trihexyltetra‐decylphosphonium bis (2,4,4‐trimethylpentyl) phosphinate

The excess molar volumes (V^E) and the deviations in molar refraction (ΔR) at 298.15 K were determined for the binary systems {diisopropyl ether (DIPE) + 1‐propanol}, {Tert‐amyl methyl ether (TAME) + methanol}, {DIPE + trihexyltetradecylphosphonium bis(2,4,4‐trimethylpentyl)phosphinate ([P_666,14][TMPP])}, {TAME + [P_666,14][TMPP]}, {methanol + [P_666,14][TMPP]} and {1‐propanol + [P_666,14][TMPP]} using a digital vibrating‐tube densimeter and a precision digital refractometer. The V^E and ΔR were correlated with the Redlich–Kister equation for binary systems. In addition, the ternary V^E and ΔR data at 298.15 K were predicted for the ternary systems {DIPE + 1‐propanol + [P_666,14][TMPP]} and {TAME + methanol + [P_666,14][TMPP]} by using the binary contribution model of Radojkovi? with correlated sub‐binary Redlich–Kister parameters. © 2011 Canadian Society for Chemical Engineering     

Application of taylor dispersion technique to measure mutual diffusion coefficient in hexane + bitumen system

A novel approach with fewer technical and analytic limitations in liquid solvent‐bitumen diffusion studies is used in this article. The Taylor dispersion technique was selected for its convenient short run time experiments and reliable data analysis to find mutual diffusion coefficients in a hexane + bitumen mixture. For the first time, the infinite‐dilution molecular diffusion coefficients of bitumen in hexane were measured in both the presence and relative absence of asphaltene particles in the solution at atmospheric pressure and temperatures of 303.15, 310.15, and 317.15 K. The polydisperse nature of bitumen was clearly revealed. Results were compared with common predictive tools. Also, the asphaltene surface charge in the hexane precipitating solvent was demonstrated. Through concentration dependency investigations at atmospheric pressure and 303.15 K, it was determined that the mutual diffusion coefficients monotonically decrease as the viscosity of mixture increases within the studied 0–34% volumetric concentration of bitumen. The Taylor dispersion technique shows great potential for diffusion studies of liquid solvent‐bitumen systems. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2670–2682, 2014     

Temperature‐Induced Changes in the Surface Wettability of SBR + PNIPA Films

We report a novel rubber film made by a simple mixing method, which realizes a steep temperature dependence of the contact angle of water at a critical temperature of 41 °C. We mixed a common SBR with a known temperature‐responsive PNIPA to make a thermo‐responsive rubber. This rubber film distinctly showed a switch of surface wettability between hydrophilic below 41 °C and hydrophobic above 41 °C. The switching property is possibly controlled by the mixing ratio of PNIPA to SBR, preparation method, added chemicals, and so on. This mixing technique will be applied for the control of surface wetting properties by temperature on various SBR‐like rubber materials, such as wet‐brake performance of automobile tires on a rainy day.

     

Numerical investigation on CO2 absorbed in aqueous N‐methyldiethanolamine + piperazine

A multiphase and multicomponent mass transfer model of CO₂ absorbed in aqueous N‐methyldiethanolamine and piperazine (PZ) was built in the study. In the model, a simple method of mass transfer between phases was proposed. Besides, the hydrodynamics, thermodynamics, and complex reversible chemical reaction were considered simultaneously. The model was validated by comparing with the previous experimental data which showed that simulated results can represent the experimental data with reasonable accuracy. Based on the model, the effects of gas velocity, liquid load and CO₂ loading on the absorption rate, and enhancement factor were analyzed. Model results showed that the enhancement factor increased with a rising gas velocity while decreased with a rising liquid load or CO₂ loading. The change of enhancement factor with CO₂ loading was similar to that of equilibrium concentration of PZ which indicated that PZ was significant to the absorption process. Furthermore, the distributions of specie concentrations were discussed in detail. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2386–2393, 2017     

Alkyne cellulose for Huisgen [3 + 2] cycloaddition with azido‐terminated targets

Azido‐grafted cellulose has been reported widely applied for further functionalization by click chemistry. As an alternative method, we proposed alkyne‐grafted cellulose as a prototype molecule for Huisgen [3 + 2] cycloaddition with azido‐terminated target compounds. Alkyne cellulose was synthesized by acylation with prop‐2‐ynyl 5‐chloro‐5‐oxopentanoate and, subsequently cycloaddition with 4‐aminophenylazide, ethyl 2‐azidoacetate, and (S)‐2‐(Azidomethyl)‐1‐(tert‐butoxycarbonyl)pyrrolidine (Boc‐pyrrolidine azide) to form triazole cellulose in a click manner. The reactions were confirmed qualitatively by Fourier transform infrared and NMR spectroscopy and analyzed quantitatively with elemental analysis data. The results show that a degree of substitution of up to 1.91 was obtained for esterification and, in most cases, was preferred completely in a selective way for the primary hydroxyl groups at the O‐6 position and partially at the O‐2 and O‐3 positions. Cycloaddition conversions were found as high as 0.95, 0.99, and 0.99 for aniline–triazole cellulose, acetate–triazole cellulose, and Boc‐pyrrolidine‐triazole cellulose, respectively. Both esterification and cycloaddition were undertaken under mild conditions without additional heating. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44410.     

A new process for fuel ethanol dehydration based on modeling the phase equilibria of the anhydrous MgCl2 + ethanol + water system

The use of ethanol as a fuel for motor engines has attracted significant attention because of its possible environmental and economic advantages over fossil fuel. However, the energy demand for the ethanol dehydration process significantly impacts its production cost. A new and energy efficient process is developed on the basis of salt extractive distillation, which uses recycled MgCl₂ granules as a separating agent. Vapor‐liquor‐equilibria (VLE) data for the ternary MgCl₂ + ethanol + water system, and the three constituent binary systems were measured at 30, 60, 90, and 101.3 kPa. A large enhancement of relative volatility of the ethanol + water system in the presence of MgCl₂ is observed throughout the entire ethanol concentration range, which completely broke the azeotrope. The salt effect of MgCl₂ is thought to be the result of energetic interactions and the hydration equilibrium reaction of the Mg²⁺ ion with water molecules. The calculation results by the mixed‐solvent electrolyte model embedded in the OLI platform equipped with new model interaction parameters and equilibrium constant (obtained via the regression of experimental VLE data), provided for a satisfactory means of simulating the MgCl₂ salt extractive distillation process. Finally, the process was proven feasible at the laboratory‐scale resulting in large granules of recovered MgCl₂ and a product of 99.5 wt % ethanol. © 2014 American Institute of Chemical Engineers AIChE J, 61: 664–676, 2015     

Thermodynamic properties of 1‐ETHYL‐3‐methylimidazolium methanesulphonate with aromatic sulphur,nitrogen compounds at T = 298.15–323.15 K and P = 1 bar

This work investigates the ability of 1‐ethyl‐3‐methylimidazolium methanesulphate ([EMIM][MeSO₃]) as a green and tuneable solvent for denitrification and desulphurisation studies. Experimental density, surface tension and refractive index data have been measured for the following systems: [EMIM][MeSO₃] (1) + pyridine (2), [EMIM][MeSO₃] (1) + pyrrole (2), [EMIM][MeSO₃] (1) + quinoline (2), [EMIM][MeSO₃] (1) + indoline (2), [EMIM][MeSO₃] (1) + thiophene (2) and [EMIM][MeSO₃] (1) + water (2) over the entire mole fraction of [EMIM][MeSO₃] at T = 298.15–323.15 K and P = 1 bar. Further from experimental density, surface tension and refractive index, coefficient of thermal expansivity, excess molar volume, deviation of surface tension and refractive index deviation were also calculated. It was found that the heteroaromatic nitrogen/sulphur compounds are completely miscible in [EMIM][MeSO₃]. The surface tension values were found to increase while the refractive index decreases with increasing mole fraction of [EMIM][MeSO₃]. The experimental values for surface tension increased in the order: pyridine > thiophene > pyrrole > indoline > quinoline > water and for refractive index: pyridine > pyrrole > indoline > quinoline > thiophene > water. It was found that the composition of [EMIM][MeSO₃] has a greater influence than temperature in deciding the surface, optical and thermodynamic properties for similar molecular interaction such as IL–thiophene and IL–pyrrole than dissimilar molecules such as IL–water. Further quantum chemical‐based COSMO‐RS tool was used to estimate the activity coefficient at different composition. © 2012 Canadian Society for Chemical Engineering     

Liquid‐liquid phase split in ionic liquid + toluene mixtures induced by CO2

High pressure carbon dioxide was dissolved in ionic liquid + toluene mixtures to obtain the conditions of pressure and composition where a liquid‐liquid phase split occurs at constant temperature. Ionic liquids (ILs) with four different cations paired with the bis(trifluoromethylsulfonyl)imide ([Tf₂N]^?) anion were selected: 1‐hexyl‐3‐methylimidazolium ([hmim]⁺), 1‐hexyl‐3‐methylpyridinium ([hmpy]⁺), triethyloctylphosphonium ([P₂₂₂₈]⁺), and tetradecyltrihexylphosphonium ([P₆₆₆₁₄]⁺). The solubility of CO₂ was measured in the liquid mixtures at temperatures between 298 and 333 K and at pressures up to 8 MPa, or until the second liquid phase appeared, for initial liquid phase compositions of 0.30, 0.50, and 0.70 mole fraction of IL. Ternary isotherms were compared with the binary solubility of CO₂ in each IL and pure toluene. The lowest pressure for separating toluene in a second liquid phase was achieved by decreasing the temperature of the system, increasing the amount of toluene in the initial liquid mixture and using [hmim][Tf₂N]. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2968–2976, 2015     

The influence of the type of oil phase on the self‐assembly process of γ‐oryzanol + β‐sitosterol tubules in organogel systems

Mixtures of γ‐oryzanol and β‐sitosterol were used to structure different oils (decane, limonene, sunflower oil, castor oil, and eugenol). The γ‐oryzanol and β‐sitosterol mixtures self‐assemble into double‐walled hollow tubules (～10 nm in diameter) in the oil phase, which aggregate to form a network resulting in firm organogels. The self‐assembly of the sterol molecules into tubules was studied using light scattering and rheology. By using different oils, the influence of the polarity of the oil on the self‐assembly was studied. The effects of temperature and structurant concentration on the tubuler formation process were determined and the thermodynamic theory of self‐assembly was applied to calculate the change in Gibbs free energy (ΔG⁰), enthalpy (ΔH⁰), and entropy (ΔS⁰) resulting from the aggregation of the structurants was determined. The self‐assembly was found to be enthalpy‐driven as characterized by a negative ΔH⁰ and ΔS⁰. A decreasing polarity of the oil promotes the self‐assembly leading to formation of tubules at higher temperatures and lower structurant concentrations.