Optimizing Trace Acetylene Removal from Acetylene/Ethylene Mixture in a Flexible Metal-Organic Framework by Crystal Downsizing.

Improving the gas separation performance of metal-organic frameworks (MOFs) by crystal downsizing is an important but often overlooked issue. Here, we report three different-sized flexible ZUL-520 MOFs (according to the crystal size from large to small, the three samples are, respectively, named ZUL-520-0, ZUL-520-1, and ZUL-520-2) with the same chemical structure for optimizing trace acetylene (CH) removal from acetylene/ethylene (CH/CH) mixture. The three differently sized activated ZUL-520 (denoted as ZUL-520a) exhibited almost identical CH uptake of 4.

Supramolecular Assembly of One-Dimensional Coordination Polymers for Efficient Separation of Xenon and Krypton.

Efficient separation and purification of xenon (Xe) from krypton (Kr) represent an industrially crucial but challenging process. While the adsorption-based separation of these atomic gases represents an energy-efficient process, achieving highly selective adsorbents remains a difficult task. Here, we demonstrate a supramolecular assembly of coordination polymers, termed as M(II)-dhbq (M = Mg, Mn, Co, and Zn; dhbq = 2,5-dihydroxy-1,4-benzoquinone), with high-density open metal sites (5.

Shell-like Xenon Nano-Traps within Angular Anion-Pillared Layered Porous Materials for Boosting Xe/Kr Separation.

Adsorptive separation of xenon (Xe) and krypton (Kr) is a promising technique but remains a daunting challenge since they are atomic gases without dipole or quadruple moments. Herein we report a strategy for fabricating angular anion-pillared materials featuring shell-like Xe nano-traps, which provide a cooperative effect conferred by the pore confinement and multiple specific interactions. The perfect permanent pore channel (4-5 Å) of Ni(4-DPDS) MO (M=Cr, Mo, W) can host Xe atoms efficiently even at ultra-low concentration (400 ppm Xe), showing the second-highest selectivity of 30.

Microgeometry-independent equation for measuring infinite dilution activity coefficients using gas-liquid chromatography with static-wall-coated open-tubular columns.

Gas-liquid chromatography is an effective method to determine infinite dilution activity coefficients (γ). Wall-coated open-tubular (WCOT) column which offers more advantages over packed column should be a preferable column type; however, the small carrier gas flow rate and stationary phase amount in WCOT columns limit its application in the determination of γ. Mathematical strategy made some progress to avoid the quantification problem in the determination of γ by static-wall-coated open-tubular (SWCOT) columns.

Engineering the Pore Size of Pillared-Layer Coordination Polymers Enables Highly Efficient Adsorption Separation of Acetylene from Ethylene.

The pore size of adsorbents plays a vital role in determining the overall separation performance of gas separation and purification by adsorption. In this work, the pore apertures of the coordination pillared layer (CPL) was systematically controlled by adjusting the length of pillared ligands. We used pyrazine, 4,4'-bipyridine, and 1,2-di(4-pyridyl)-ethylene with increased length to synthesize CPL-1 (L = pyrazine), CPL-2 (L = 4,4'-bipyridine), and CPL-5 [L = 1,2-di(4-pyridyl)-ethylene], respectively.

Highly efficient treatment of textile dyeing sludge by CO thermal plasma gasification.

Textile dyeing sludge is complex hazardous material with increasing amount year by year, and the conventional treatment techniques are limited by many drawbacks such as water/soil contamination, incomplete degradation of hazardous organics or inefficient fixation of toxic heavy metals. This work reported the first example of thermal plasma gasification treatment of textile dyeing sludge in a homemade rotating arc plasma reactor, which not only significantly reduced the volume and eliminated the safety risk of textile dyeing sludge, but also produced valuable syngas that can be used for chemical industry. At a feed rate of 36 g/min and a CO flow rate of 0.

Inverse Adsorption Separation of CO/CH Mixture in Cyclodextrin-Based Metal-Organic Frameworks.

The demand for CO/CH separation, especially the removal of CO impurity, continues to grow because of the high-purity CH required for various industrial applications. The adsorption separation of CH and CO via porous materials is gaining a considerable attention as it is more energy-efficient compared with cryogenic distillation. The ideal porous materials are those that preferentially adsorb CO over CH; however, very few adsorbents meet such requirement.

Hybrid Deep Eutectic Solvents with Flexible Hydrogen-Bonded Supramolecular Networks for Highly Efficient Uptake of NH.

Serious environmental concerns have led to a great demand for efficient uptake of NH by solvents. However, traditional aqueous absorbents have many shortcomings and efforts to use ionic liquids have met with limited success. A hybrid deep eutectic solvents (DESs) designed with a flexible hydrogen-bonded supramolecular network exhibits both exceptional NH uptake capacity and superior desorption-regeneration performance, along with superb NH /CO selectivity and environmental merit.

Enhanced self-assembly for the solubilization of cholesterol in molecular solvent/ionic liquid mixtures.

The development of new solvents combining greatly enhanced solubility for sparingly soluble compounds and good kinetic properties is challenging. In this study, we constructed a family of new molecular solvent/ionic liquid (IL) mixtures with amphiphilic, anionic functional long-chain carboxylate ionic liquids (LCC-ILs) as a key component for the solubilization of sparingly soluble compounds, using cholesterol as a model solute. Polarized optical microscopy (POM), wide angle X-ray diffraction (WAXD), Fourier-transform infrared (FTIR) spectra and H NMR showed that ordered mesoscopic structures, such as liquid crystals (LCs), were formed when cholesterol was dissolved in the mixtures, presenting a self-assembly induced dissolution mechanism driven by H-bond interaction and van der Waals forces in the mixtures.

Incorporation of N-Methyl-d-glucamine Functionalized Oligomer into MIL-101(Cr) for Highly Efficient Removal of Boric Acid from Water.

Polymeric resins are practically important adsorbents in a wide variety of applications, but they generally suffer from low surface areas and limited functionalized adsorption sites owing to their closely compacted and tangled polymeric chains. A metal-organic framework (MOF)-polymer composite with enhanced adsorption capacity against the compacted polymeric resins was reported. The strategy to incorporate functionalized oligomer within the cavities of the MOF was demonstrated by the preparation of MIL-101(Cr) incorporated with N-methyl-d-glucamine-based organosiloxane polymer.

Nonaqueous lyotropic ionic liquid crystals: preparation, characterization, and application in extraction.

A class of new ionic liquid (IL)-based nonaqueous lyotropic liquid crystals (LLCs) and the development of an efficient IL extraction process based on LC chemistry are reported. The nonaqueous LLCs feature extraordinarily high extraction capacity, excellent separation selectivity, easy recovery, and biocompatibility. This work also demonstrates that the introduction of self-assembled anisotropic nanostructures into an IL system is an efficient way to overcome the intrinsically strong polarity of ILs and enhances the molecular recognition ability of ILs.

Preparation of porous cellulose 3,5-dimethylphenylcarbamate hybrid organosilica particles for chromatographic applications.

Organic-inorganic hybrids incorporating cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC)-functionalized silica particles can exhibit a high loading capacity with high loadings of the chiral selector. These materials offer considerable potential for use in preparative chiral separations. However, the preparation of these hybrid particles with high surface areas and controlled organic/inorganic ratios is challenging.

Immobilization of Ag(i) into a metal-organic framework with -SO3H sites for highly selective olefin-paraffin separation at room temperature.

Introduction of Ag(i) ions into a sulfonic acid functionalized MOF ((Cr)-MIL-101-SO3H) significantly enhances its interactions with olefin double bonds, leading to its much higher selectivities for the separation of C2H4-C2H6 and C3H6-C3H8 at room temperature over the original (Cr)-MIL-101-SO3H and other adsorbents at room temperature.

One of the distinctive properties of ionic liquids over molecular solvents and inorganic salts: enhanced basicity stemming from the electrostatic environment and "free" microstructure.

The basicity of ionic liquids (ILs) underlies many important IL-based processes including the dissolution and conversion of cellulose, the capture of CO2, and metal catalysis. In this work, we have disclosed the nature of the basicity of ILs, i.e.

Enhancing the basicity of ionic liquids by tuning the cation-anion interaction strength and via the anion-tethered strategy.

Ionic liquids (ILs) with relatively strong basicity often show impressive performance in chemical processes, so it is important to enhance the basicity of ILs by molecular design. Here, we proposed two effective ways to enhance the basicity of ILs: by weakening the cation-anion interaction strength and by employing the anion-tethered strategy. Notably, two quantum-chemical parameters, the most negative surface electrostatic potential and the lowest surface average local ionization energy, were adopted as powerful tools to demonstrate the electrostatic and covalent aspects of basicity, respectively, at the microscopic level.

Synthesis and characterization of cellulose 3,5-dimethylphenylcarbamate silica hybrid spheres for enantioseparation of chiral β-blockers.

A cellulose derivative-based chiral stationary phase (CSP) is considered one of the most widely applied CSPs due to its powerful enantioseparation ability. The high loading capacity and mechanical strength of CSPs are crucial for their application in preparative chromatography, such as a simulated moving bed. Compared to traditional cellulose-based CSPs that have been adsorbed onto chromatographic supports, organic-inorganic hybrid CSPs exhibit a potentially higher loading capacity and mechanical strength by increasing the density of chiral recognition groups.

Salt-enhanced removal of 2-ethyl-1-hexanol from aqueous solutions by adsorption on activated carbon.

2-Ethyl-1-hexanol has extensive industrial applications in solvent extraction, however, in view of its potential pollution to environment, the removal and recovery of 2-ethyl-1-hexanol is considered an essential step toward its sustainable use in the future. In this work, we report the removal of 2-ethyl-1-hexanol from aqueous solutions containing salts in high concentrations by adsorption on a coal-based activated carbon. Adsorption thermodynamics showed that the experimental isotherms were conformed well to the Langmuir equation.

Separation of long chain fatty acids with different number of unsaturated bonds by fractional extraction: experimental and COSMO-RS study.

Long chain unsaturated fatty acids (LCUFAs) are important food components and dietary supplements due to their beneficial health effects. The key process to produce high-purity LCUFAs is to separate long chain fatty acids (LCFAs) with different degrees of unsaturation and chain lengths. This process faces great challenge because of similar physico-chemical properties of fatty acids concerned.

Enantiomeric separation of citalopram base by supercritical fluid chromatography.

The chiral separation of citalopram base by supercritical fluid chromatography on a semipreparative Chiralpak AD column was studied with the use of three alcohol-type modifiers (methanol, ethanol, and 2-propanol) with different volume percentages (5, 10, and 15%). The best separation was achieved when 10% 2-propanol was used in the presence of 0.1% diethylamine as additive.

Feasibility of ionic liquids as extractants for selective separation of vitamin D₃ and tachysterol₃ by solvent extraction.

A selective separation of vitamin D₃ and tachysterol₃ by solvent extraction with 7 organic solvents and 11 ionic liquids (ILs) has been reported. Among organic solvents sulfolane showed optimal extraction performance, giving only a selectivity of 1.44 for tachysterol₃ over vitamin D₃.

Mathematical modeling of the impact of actin and keratin filaments on keratinocyte cell spreading.

Keratin intermediate filaments (IFs) form cross-linked arrays to fulfill their structural support function in epithelial cells and tissues subjected to external stress. How the cross-linking of keratin IFs impacts the morphology and differentiation of keratinocytes in the epidermis and related surface epithelia remains an open question. Experimental measurements have established that keratinocyte spreading area is inversely correlated to the extent of keratin IF bundling in two-dimensional culture.

Accurate measurements of infinite dilution activity coefficients using gas chromatography with static-wall-coated open-tubular columns.

Wall-coated open-tubular (WCOT) columns provide higher column efficiency and lower solute interfacial adsorption effect than packed columns. However, previous efforts used to measure the infinite dilution activity coefficient (γ(∞)) via a chromatographic technique have used packed columns, because the low carrier gas flow rate (U) and the small stationary phase amount (n(2)) in WCOT columns raise large errors. By rationally revising the γ(∞)-calculation equation for static-wall-coated open-tubular column, we observed that U and n(2) are not necessarily needed and the resulting error could be reduced, and WCOT column gas chromatography subsequently became a superior method for the accurate γ(∞) determination.

Differential solubility of ethylene and acetylene in room-temperature ionic liquids: a theoretical study.

The room-temperature ionic liquids (RTILs) have potential in realizing the ethylene (C(2)H(4)) and acetylene (C(2)H(2)) separation and avoiding solvent loss and environmental pollution compared with traditional solvents. The interaction mechanisms between gases and RTILs are important for the exploration of new RTILs for gas separation; thus, they were studied by quantum chemical calculation and molecular dynamics simulation in this work. The optimized geometries were obtained for the complexes of C(2)H(4)/C(2)H(2) with anions (Tf(2)N(-), BF(4)(-), and OAc(-)), cation (bmim(+)), and their ion pairs, and the analysis for geometry, interaction energy, natural bond orbital (NBO), and atoms in molecules (AIM) was performed.

Separation of soybean isoflavone aglycone homologues by ionic liquid-based extraction.

The separation of a compound of interest from its structurally similar homologues is an important and challenging problem in producing high-purity natural products, such as the separation of genistein from other soybean isoflavone aglycone (SIA) homologues. The present work provided a novel method for separating genistein from its structurally similar homologues by ionic liquid (IL)-based liquid-liquid extraction using hydrophobic IL-water or hydrophilic IL/water-ethyl acetate biphasic systems. Factors that influence the distribution equilibrium of SIAs, including the structure and concentration of IL, pH value of the aqueous phase, and temperature, were investigated.