Purpose: To prepare polystyrene nanofiber ion exchangers (PSNIE) with surface cation exchange functionality using a new method based on electrospinning and also to optimize crosslinking and sulfonation reactions to obtain PSNIE with maximum ion exchange capacity (IEC). Method: The nanofibers were prepared from 15% w/v polystyrene solution in dimethylacetamide (DMAc) containing 0.025 %w/v tetrab...

Nowadays, in many rangelands, due to over grazing, and problems that some plantshave in germination, the rate of forage production is greatly reduced. So to take advantages ofthe benefits of such plants, it is necessary to identify and remove barriers of germination andestablishment of suitable plants. The present study was designed to investigate differenttreatments of breaking dormancy and st...

DRIFTS, was used to study small organic molecules, with and without functional groups, adsorbed to the surface of γ-alumina and kaolinite clay from a non-polar solvent. Adsorbed water is present on the surface of both minerals and this influences the adsorption of organic molecules from, the non-polar solvent, onto the mineral surface, particularly the interaction of polar functional groups wit...

Atmospheric new particle formation (NPF) is a key source of ambient ultrafine particles that may contribute substantially to the global production of cloud condensation nuclei (CCN). While NPF is driven by atmospheric nucleation, its impact on CCN concentration depends strongly on atmospheric growth mechanisms since the growth rate must exceed the loss rate due to scavenging in order for the pa...

Molecular dynamics method is applied to study the structure of stable sulfuric acid–water clusters at various compositions. Also a planar liquid–vapor interface is studied. Two different potential models were used. In the simpler model, sulfuric acid (H 2 SO 4 ) remains in an undissociated state. A more realistic scheme requires that in the presence of water (H 2 O) H 2 SO 4 protonates to form ...

Camptothecin-20-propinate (CZ48) and other camptothecin ester derivatives were prepared by the esterification reactions of camptothecin or 9-nitrocamptothecin with the corresponding acylating agents such as organic acid anhydride or chloride with concentrate sulfuric acid as the catalyst. The sulfuric acid-catalyzed reactions gave high yields of camptothecin ester products.Among the 11 compound...

The problem of estimating quantitatively the components of a mixture of naturally occurring estrogens has been attacked through the preparation of their p-phenylazobenzoyl (azoyl) esters and separating these esters by the chromatographic adsorption technique (1). By this method, the monoazoates were quantitatively separated from the diazoates. Hydrolysis of these esters and suitable extraction ...

A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3'-indoline]-pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this pro...

(1) If heated with iodine as a catalyst, the tertiary alcohol (I) readily yielded the olefin (III). (2) This olefin rearranged immediately to the dicyclic hydrocarbon (II) when digested with concentrated sulfuric acid. (3) Treated with the proper concentration of sulfuric acid, or phosphoric acid, the alcohol (I) passed immediately to the olefin (III), which on longer treatment changed to the i...