the role of polymeric additives such as pvp and peg is studied with respect to the morphology of pes porous layer as a sublayer of nanofiltration composite membranes based on pes/pa. results show that by phase inversionprocess of quaternary systems comprised of four components of polymer/solvent/non-solvent/additive and the diffusion of intertwined polymers some changes occur in membrane morpho...

selectfluor [1-(chloro methyl) -4-flouro -1,4-di azonia bicyclo[2,2,2] octane bis (tetraflouro-borate)] catalyzed the preparation of quinoxaline and 2,3-dihydo pyrazine derivatives through one -pot condensation of 1,2-di amines with 1,2-di carbonyls in solvent and under solvent- free conditions. this catalyst is commercially available, inexpensive, reusable, stable to air and moisture, and rela...

two dimensional thin layer chromatography on polyamide sheets is a useful method for identification of pth-amino acids which have very close rf-values. the solvent systems described here are particularly effective and have an edge over other solvent systems used for the separation of pth-amino acids. the solvent systems provide a clear separation of all pth-amono acids except lle / leu in a rel...

A new, sensitive and fast dispersive liquid-liquid microextraction (DLLME) coupled with micro-solid phase extraction (μ-SPE) was developed for determination of zearalenone (ZEN) in wheat samples. The DLLME was performed using acetonitrile/water (80:20 v/v) as the disperser solvent and 1-octanol as the extracting solvent.  The acetonitrile/water (80:20 v/v) solvent was also used to extract ZEN f...

P2O5-SiO2 (30% w/w) was found to be a useful catalyst for the synthesis of various 2-substituted aryl benzimidazoles under solvent-less and in solvent conditions from o-phenylenediamine and aldehydes. The products were directly recrystallized from methanol.

P2O5-SiO2 (30% w/w) was found to be a useful catalyst for the synthesis of various 2-substituted aryl benzimidazoles under solvent-less and in solvent conditions from o-phenylenediamine and aldehydes. The products were directly recrystallized from methanol.