Comments on the size of the adsorbed phase in porous adsorbents

An alternative to the conventional ‘pore filling model’ for describing Gibbsian surface excess (GSE) isotherm from a liquid mixture on a porous adsorbent is proposed where the adsorbed phase volume is treated as a variable. The new model is tested using GSE isotherm data on various micro and mesoporous adsorbents. The adsorbed phase volume is found to be system specific but always less than the adsorbent pore volume, irrespective of the pore size.     

Studies towards the Synthesis of Alkyl N‐(4‐Nitrophenyl)‐3/2‐oxomorpholine‐2/3‐carboxylates

The syntheses of methyl 4‐(4‐nitrophenyl)‐3‐oxomorpholine‐2‐carboxylate ( 3a ) and ethyl 4‐(4‐nitrophenyl)‐2‐oxomorpholine‐3‐carboxylate ( 5b ), important building blocks for the synthesis of factor Xa inhibitor rivaroxaban analogs with potential dual antithrombotic activity, via Rh₂(OAc)₄‐catalyzed O? H and N? H carbene insertion reactions are described.     

Numerical simulation of rapid pressurization and depressurization of a zeolite column using nitrogen

The required durations of pressurization and depressurization steps of a rapid pressure swing adsorption process are primarily governed by adsorbent particle size, adsorption kinetics, column pressure drop, column length to diameter ratio, and the valve constant of the gas inlet and outlet control valve attached to the adsorbent column. A numerical model study of the influence of these variables for an adiabatic LiX zeolite column is presented using pure N₂ as an adsorbate gas. An adsorbent particle size range of 200–350 μm was found to minimize (<1 s) the times required for the pressurization and depressurization steps.     

Identification of elastomer blends by thermal analysis

Identification of a number of commercial polyblends as well as vulcanized elastomer blends has been studied by differential scanning calorimetry (DSC) in nitrogen and oxygen between 0°C and 500°C. The raw blends included are PVC-NBR and ABS resin. The vulcanized elastomer blends studied are EPDM-BR, or -NR; chlorobutyl- BR, -SBR, or -NR; CR-NR, -BR, or -SBR; and NR-BR, -SBR. DSC patterns for degradation are retained in the blend and polymeric constituents can be identified from their thermographs in most cases.     

Publications on Adsorption Science and Technology

A key word search of Chemical Abstracts Registry and Derwent Patent Index on various topics of Adsorption Science and Technology between 1970–2000 reveals an immense volume of patents and publications in this area. A detailed breakdown of this search is provided.     

Ein Verfahren zur Bestimmung des Austrocknungszrades von Teakholz

Ohne Zusammenfassung     

Deprotection of thioacetals and 1,3-dithianes with dimethylsulphoxide

The dialkylthioacetals, cyclic ethanediylthioacetals and 1,3-dithianes are shown to undergo facile dethioacetalization on heating in dimethylsulphoxide under neutral conditions to afford the corresponding carbonyl compounds in good yields.