Extension of The Applicability of Jäntti's Method For Fast Calculation of Adsorption Data

The time for adsorption measurements can be substantially reduced by measuring several values at short time intervals at the beginning of the kinetic curve and extrapolation of the equilibrium value. The method used by Jäntti for simple adsorption processes has been extended for complicated processes using a second order differential equation. A simulated example is calculated.     

A Heterometallic MOF based on Monofunctional Linker by “One-pot” Solvothermal Method for Highly Selective Gas Adsorption

Heterometallic MOFs, as an important branch of MOF materials, open up a new way to design and synthesize innovative MOF materials. Hence, it has positive significance for the development of MOF materials. By utilizing monofunctional linker CBDA [5,5'-(carbonylbis(azanediyl))-diisophthalic acid], a heterometallic MOF In/Gd-CBDA was obtained under “one-pot“ solvothermal method. The three-dimensional framework exhibits (3,4,6)-connected network belonging to a new topology. In addition, the synthetic conditions that affect the growth of crystal have been studied in detail. Numerous experiments led to the finding that the type and composition of solvents are very important for inducing the recognition of carboxylic acid groups at different positions coordination to diverse metals. Furthermore, the mechanism of this kind of heterometallic MOFs assembled by monofunctional linker under “one-pot” solvothermal method has been clarified, which is mainly related to the steric hindrance of functional groups and the properties of heterometals. Based on ideal adsorbed solution theory (IAST), In/Gd-CBDA shows the efficient selective gas adsorption, especially for equimolar mixtures of CO₂/CH₄ (13) and C₃H₈/CH₄ (321). This work of heterometallic MOF material assembled by monofunctional linker under “one-pot” solvothermal method provides a new platform for the development of MOF materials in terms of enriching the topological family and broadening possibilities in advanced applications.     

Efficient Method for the Synthesis of Benzimidazoquinazoline Derivatives with Three‐Point Diversity

An efficient strategy for the preparation of a novel heterocyclic ring system of benzimidazoquinazolines with three‐point diversity has been described. The compounds were obtained by treating o‐phenylene diamines with o‐nitrobenzaldehyde to give benzimidazoles, followed by reduction of the nitro group to give an amine. Derivatization of the resulting amine with isothiocyanates followed by in situ cyclodesulfurization at rt furnished the title compounds in high yields and purities.     

Direct Method for Measuring Adsorption at the Aqueous Solution–Gas Interface Based on the Stabilization of Foam Films in Hydrophobic Tubes. The Adsorption Isotherm of Sodium Dodecyl Sulfate

It was found that the hydrophobization of the inner surface of a tube offers the stabilization of films of nonfoaming aqueous solutions closing the cross section of the tube. Based on this phenomenon, a modification of the known method of determining adsorption at the solution surface based on the separation of foam films from the solution was proposed for extending the potentialities of this method to nonfoaming solutions. Adsorption of sodium dodecyl sulfate on the aqueous solution–air interface was investigated in the range of low concentrations, which earlier was not easily accessible to measurements by known methods.     

Method for Metal Dispersion Measurements on Pt-Sn/γ -Al2O3

An easy, inexpensive method for metal dispersion measurements in Pt-Sn/γ -Al₂O₃ catalysts is proposed. The method is based in avoiding Sn oxidation during catalyst evacuation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Study on Pressure Swing Adsorption Removing C2^＋ from Natural Gas as Raw Material for Thermal Chlorination

The experimental investigation demonstrates that a setisfactory can be expected for pressure swing adsorption (PSA) purification of natural gas as raw material for thermal chlorination process.Using hh-4 molecular sieve as adsorbent for removing C2^ components,the suitable adsorption pressure is 0.4-0.45 MPa,desorption vacuum is 0.08-0.09 MPa and circulation time is 20-21 min.     

Effect of Fluorination on the Crystal Structure,Stability and Gas Adsorption Property in Zinc (Ⅱ) Metal-organic Frameworks

Three zinc(Ⅱ) metal-organic frameworks (x F-MAC-3) have been synthesized by using Zn(Ⅱ) salts,3,5-dimethyl-1H-1,2,4-triazole (Hdmtrz) and different fluorination degree carboxylate ligands,which are analogic structures and can be described as (6,6)-connected pcu-b net.We find that the fluorine atoms have structural regulation effect on x F-MAC-3,which can not only enlarge the torsion angle φ of carboxylate ligands but also elevate the space group of structures.Besides,the CO₂-273 K upt...     

Gas Chromatographic Enantiomer Separation of Cyclopropane Derivatives on Three 2, 6-Di-O-allyl-3-O-acylated-β-cyclodextrins Chiral Stationary Phases

Eight pairs of enantiomers of cyclopropane derivatives were resolved on capillary gaschromatographic columns using three new 2, 6-di-O-allyl-3-O-acylated-β-cyclodextrins as chiralstationary phases. It was found that the three β-CDs can separate some of the racemic cyclopropanederivatives well.