Individual solvation numbers around the nickel(II) ion have been determined by titration Raman spectroscopy in N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA) mixtures at 298 K. The in-plane bending vibration (delta(O=C-N)) of DMF and the stretching vibration (v(N-CH3)) of DMA were used in the present analysis. These Raman bands of solvent molecules shift to higher frequencies upon ...

A novel polyimide (PI)/clay hybrid nanocomposite, designated as PI (PAAS)/CM, has been developed from the poly(amic acid) salt of triethylamine and organomontmorillonite (CM) using a mixture solution of tetrahydrofuran (THF) and methanol (MeOH). For comparison, two other PI/clay hybrids derived from poly(amic acid) and CM in THF/MeOH solution and N,N9-dimethylacetamide (DMAc) solution, denoted ...

Nonsolvent-induced phase separation (NIPS) is widely used to prepare asymmetric gas membranes. Most industrial NIPS casting solution formulations are limited a small group of glassy polymers and, importantly, require toxic polar aprotic solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), or N-methyl-2-pyrrolidone (NMP). Growing restrictions on the use spurring search for...

A series of novel aromatic polyamides with pendent 4,40-dimethoxy-substituted triphenylamine (TPA) units were prepared via the direct phosphorylation polycondensation from a new dicarboxylic acid monomer, N,N-bis(4-carboxyphenyl)-N0,N0-di(4-methoxyphenyl)-1,4-phenylenediamine (4), and various aromatic diamines. These polyamides were amorphous with good solubility in many organic solvents, such ...

groups activated under the treatment with diphenyl phosphorazidate7) and triethylamine or N,N'-dicyclohexylcarbodiimide and I-hydroxy1 H-benzotriazole mixtures. The reaction was carried out in N,N-dimethylformamide or N,Ndimethylacetamide, at room temperature, using an excess of the reagents. The course of the reaction was followed by means of thin-layer chromatography on silica gel with the so...