Alkali penetration

When electrolytic iron foil is immersed in concentrated solutions of jodium or potassium hydroxide for several weeks, and, after thorough cleaning, allowed to corrode in distilled water, the latter gradually becomes contaminated with traces of sodium or potassium salts, the bresence of which can be detected by the spectroscope or by the usual Bunsen flame test.6 Similar results have been obtained with lithium lydroxide, barium hydroxide, and with ammonia.7 It appears probable hat the alkali penetrates in minute quantities into the metal between he ferrite crystals, possibly in consequence of a certain amount of borosity in the intercrystalline cement. This theory is supported by he fact that iron which has been soaked in alkali invariably pits ... 

Alkalis penetrate the skin slowly, making the extent of damage dependent on the duration of contact. Affected skin should be washed with running water until free of alkali as indicated by the disappearance of the soapy feeling. 

In many of the samples in the alkali-rich zone the alkali literally fills all pores in the structure. Thus, one possible mechanism of alkali disruption may involve alternative freezing and thawing of this alkali. During cooling, alkali freezes and then cracks, which forms voids. If more molten alkali penetrates into these voids as the temperature of the hot face is increased, then all voids are filled before the frozen alkali can melt. When the original alkali does melt there is no place for the alkali to migrate or expand thus structural disruption may result. 

Dilute alkali penetrates only accessible regions of the fiber causing intercrystalline or interfibrillar swelling. The latter is much more profound in that it brings about changes in crystal structure of the fibers, as evidenced by mercerization (in the case of alkali) and the formation of ammonia cellulose (in the case of liquid ammonia). 

Many inorganic solids lend themselves to study by PL, to probe their intrinsic properties and to look at impurities and defects. Such materials include alkali-halides, semiconductors, crystalline ceramics, and glasses. In opaque materials PL is particularly surface sensitive, being restricted by the optical penetration depth and carrier diffusion length to a region of 0.05 to several pm beneath the surface. 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials Attacks copper and copper alloys these metals should not be used. Penetrates leather, so contaminated leather shoes and gloves should be destroyed. Attacks aluminum in high concentrations Stability During Transport Stable Neutralizing Agents for Acids and Caustics Not pertinent Polymerization May occur spontaneously in absence of oxygen or on exposure to visible light or excessive heat, violently in the presence of alkali. Pure ACN is subject to polymerization with rapid pressure development. The commercial product is inhibited and not subject to this reaction Inhibitor of Polymerization Methylhydroquinone (35 - 45 ppm). 

Though inert to acids, sand is affected by alkalies, and its spherical particle shape allows deeper solids penetration and quicker clogging than does coal. With the... 

Wire-ropes are well lubricated when, manufactured however, this lubrication will hot last throughout the entire service, life of the rope. Periodically, therefore, the rope will - need to be field lubricated. When necessary, lubricate the tope with a good grade Of lubricant that will penetrate and adhere tO the rope, and that,is free from acid or.alkali,, ... 

Cathodic disintegration can occur with lead, observable as a grey cloud of fine metal particles. Hydrogen evolved on the surface of the lead can be absorbed if the current density is sufficiently high . Above this level, avalanche penetration can occur, feadipg to the formation of lead hydride, which leads to disintegration in the manner described . Electrochemical implantation pf alkali metals Can also lead to disintegration, ... 

The immobilization of dissolved chemical species by adsorption and ion exchange onto mineral surfaces is an important process affecting both natural and environmentally perturbed geochemical systems. However, sorption of even chemically simple alkali elements such as Cs and Sr onto common rocks often does not achieve equilibrium nor is experimentally reversible (l). Penetration or diffusion of sorbed species into the underlying matrix has been proposed as a concurrent non-equilibration process (2). However, matrix or solid state diffusion is most often considered extremely slow at ambient temperature based on extrapolated data from high tem-... 

Mass fluxes of alkali elements transported across the solid-solution interfaces were calculated from measured decreases in solution and from known surface areas and mineral-to-solution weight-to-volume ratios. Relative rates of Cs uptake by feldspar and obsidian in the batch experiments are illustrated in Figure 1. After initial uptake due to surface sorption, little additional Cs is removed from solution in contact with the feldspars. In contrast, parabolic uptake of Cs by obsidian continues throughout the reaction period indicating a lack of sorption equilibrium and the possibility of Cs penetration into the glass surface. 

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