Abstract  This OECD Emission Scenario Document (ESD) is intended to provide information on the sources, use patterns, and potential release pathways of non-volatile chemicals used in textile dyes. The document focuses primarily on the application of dyes to fibers, yarns and fabrics by batch or continuous processes. The document presents standard approaches for estimating the environmental releases of and occupational exposures to non-volatile chemicals used in dye formulations.

Abstract  Membranes were prepared from a casting solution of a water-soluble polymer, poly (vinyl pyrrolidone) (PVP), and a membrane forming polymer, poly(ether sulfone), in 1-methyl-2-pyrrolidone (NMP) as solvent by immersing them in mixtures of water and NMP. It was found that the addition of PVP to the ternary system suppresses the formation of macrovoids in the sub-layer, while the ultrafiltration-type top-layer consists of a closely packed layer of nodules. Using a model for mass transfer in this quaternary system, it is possible to explain the effects of the additive on macrovoid formation. Strong indications are found that the appearance of a nodular structure in the top-layer follows a mechanism of spinodal decomposition during the very early stages of the immersion step.

Abstract  We have prepared and characterized polyaniline in the form of thin free-standing films and films formed by spin coating. The films are formed from solution with chemically prepared base polyaniline (emeraldine) which is dissolved in N-methyl-2-pyrrolidone. The films, as prepared and doped with HCl, have conductivities in the range 60-70 S/cm. Optical reflection spectra reveal metallic-like films. Furthermore, we have been able to align the polyaniline (PANi) chains using uniaxial stress. Elongation ratios of up to 650% have been achieved so far. When doped with HCl these films yield conductivities of up to 350 S/cm and anisotropy sigma-parallel to/sigma-perpendicular to of up to 24. Initial polarized reflection spectra reveal optical anisotropy.

Abstract  Modification of polymeric membrane materials by incorporation of hydrophilicity results in membranes with low fouling behavior and high flux. Hence, polyetherimide (PEI) was functionalized by sulfonation and ultrafiltration membranes were prepared based on cellulose acetate (CA) and sulfonated poly (ether imide) (SPEI) in various blend compositions in N-methyl-2-pyrrolidone (NMP) as solvent by phase inversion technique. Prepared membranes were subjected to ultrafiltration characterizations such as compaction, pure water flux, water content, and membrane hydraulic resistance. All CA/SPEI blend membranes had substantially higher pure water flux, water content, and reduced hydraulic resistance compared to the pure CA membrane. Further, all of these above properties varied systematically with variation of SPEI content. Studies were carried out to find the rejection and permeate flux of macromolecular proteins such as trypsin, pepsin, egg albumin (EA), and bovine serum albumin (BSA) and toxic heavy metal ions such as Cu(2+), Ni(2+), Zn(2+), and Cd(2+) using polyethyleneimine as the chelating agent. On increasing the concentration of SPEI, the rejection of proteins and metal ions decreases whereas the permeate flux has an increasing trend. The molecular weight cut-offs (MWCO) of the blend membranes were determined using protein separation studies found to vary from 20 to 69 kDa, depending on the various polymer compositions. In general it was found that CA/SPEI blend ultrafiltration membranes demonstrated better performance compared to the membranes prepared from pure cellulose acetate.

Abstract  Liquid-phase exfoliation is one of the most promising routes for large-scale production of multilayer graphene dispersions. These dispersions, which may be used in coatings, composites, or paints, are believed to contain disorder-free graphene multilayers. Here, we address the nature of defects in such samples obtained by liquid-phase exfoliation of graphite powder in N-methyl-2-pyrrolidone. Our Raman spectroscopy data challenge the assumption that these multilayers are free of bulk defects, revealing that defect localization strongly depends on the sonication time. For short ultrasound times, defects are located mainly at the layer edges but they turn out to build up in the bulk for ultrasonic times above 2 h. This knowledge may help to devise better strategies to achieve high-quality graphene dispersions.

Abstract  The effectiveness of Koch-Sulzer BX structured packing and random protruded packing are compared for an extractive distillation operation which exhibits high liquid to vapor ratios. The extractive distillation operation studied separated an 88/12wt% toluene/heptane mixture with N-methyl pyrrolidone (NMP) as the solvent in a 0.15 m diameter column with about 5.5 m of packing. The effect of pressure drop and HETP on gas capacity factor, liquid loading and liquid-to-vapor ratio are examined.

Abstract  The examination of the structural characteristics of the substances extracted from four coal samples, using N-methyl-2-pyrrolidinone, was carried out by pyrolysis-field ionization mass spectrometry (Py-FIMS). The extracts are complex mixtures of relatively easily distillable components and of larger entities, supposed to be "oligomeric" parts of the coal structure, which are pyrolyzed above 400-degrees-C with the production of hydroxylated derivatives. Polycondensed structures predominate (4 to 7-8 nuclei) in a wide range of m/z values, mainly 250-350. This work can serve as a basis for further studies on the carbonization process of coals and the role of "the extractible phase" in the first stages of the plastic state and the process of coal softening.