Solvent fingering

In summary, the understanding of electrical polarization at liquid-liquid interfaces has improved much over the past decades, expanding beyond the classical Gouy-Chapman analysis. After many years of extensive capacitance data measurements for different solvent pairs, electrolytes, and so on, the different theoretical approaches all point toward a three-layer model in which the outer layers are classical diffuse layers that can be treated in a first approximation by the Poisson-Boltzmann equation, and a central layer that ions from both side can penetrate, and where solvent fingering may take place, and where the surface roughness is... 

CAUTION. Sodium must be handled with great care and under no circumstances may the metal be allowed to come into contact with water as a dangerous explosion may result. Sodium is stored under solvent naphtha or xylene it should not be handled with the fingers but with tongs or pincers. Waste or scrap pieces of sodium should be placed in a bottle provided for the purpose and containing solvent naphtha or xylene they should never be thrown into the sink or into the waste box. If it is desired to destroy the scrap sodium, it should be added in small portions to rather a large quantity of methylated spirit. 

Solvent-borne adhesives. Although the NR polymer is inherently tacky, tack-ifying resins are generally added to improve bonding to polar surfaces. Because the solids content in these adhesives is lower than 35 wt%, they are not suitable for gap filling. The quick-grab (cements) adhesives are particular because they contain about 65 wt% rubber, and set within a few seconds under finger pressure. 

Another piece of glassware used in synthetic procedures is the cold finger condenser (Fig. A3.7). Used in the case where the reaction is carried out in a low-boiling solvent (for example, liquid ammonia), the condenser is filled with a suitable cooling mixture and fitted with a drying tube. 

Anderson, M. R., Johnson, R. L., and Pankow, J. F., 1992, Dissolution of Dense Chlorinated Solvents into Groundwater. Modeling Contaminant Plumes Form Fingers and Pools of Solvent Environmental Science and Technology, Vol. 26, No. 5, pp. 901-907. 

Column Chromatography. The hexane layer corresponding to sample 4-4 was separated and the solvent evaporated. The residue was adsorbed on a silica gel column, and eluted with hexane. The IR spectrum of the first fraction was identical with that of an authentic sample of TBTC1. Frequencies in the finger-print region, in cm-1 1464 (s), 1416 (m), 1377 (s), 1359 (w), 1342 (m), 1293... 

This discussion brings out an important principle that will reappear time and again in this chapter. If we can assign the absolute direction of the hand vis-a-vis the polar axis b (Figure 2), that is, establish whether the wrist or the fingers of the hand point up, then the absolute chirality of the hand is fixed as well. This determination of absolute polarity can be achieved in several ways other than anomalous scattering of X-rays or neutrons, for example, by an external means such as a solvent, a chemical reagent, or a physical measurement (e.g.,... 

TelluranthreneP Finely powdered tellurium (2.3 g, 18 mmol) and 2.5 g (9.0 mmol) of o-phenylenel mercury are intimately mixed by grinding in a mortar, the mixture is placed in the well of a sublimation apparatus, which is then evacuated to <1 torr. The well of the sublimation apparatus is heated at 250°C in a bath of Wood s metal for 10 h, and the cold finger is cooled with dry ice. The sublimed solids are dissolved in chloroform, the solution is decanted through a filter, the solvent is evaporated, and the residue is recrystaUized from carbon tetrachloride or ethanol/benzene. Yield 1.05 g (57%). m.p. 179°C. 

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