Iodine absorption number

A carbon black sample is treated with excess of iodine. The excess iodine is then titrated with a sodium thiosulfate solution. The result is expressed as adsorbed iodine per unit of mass of the sample. The iodine number depends on amount of volatiles, surface porosity, and extractables. The iodine number correlates with the nitrogen specific surface area. It is a simple method used to evaluate the quality of carbon black. 

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ASTM D 1510-96. Carbon black - iodine absorption number. 

Type Designation Production process and Acronym ASTM feedstock Average primary particle size (nm) Iodine absorption number (gjkg) Primary rubber processing properties and use... 

A.O.A.C. 17 edn, 2000c, Official method 920, 159 Iodine absorption number of oils and fats. 

Table 9 shows the classification system for blacks most commonly used in mbber. The ASTM numbering system is based on the fundamental particle si2e of the black. Particle si2e is deterrnined by several methods, including iodine absorption, nitrogen absorption, and light scattering. 

Soon after Dennison had deduced from the specific-heat curve that ordinary hydrogen gas consists of a mixture of two types of molecule, the so-called ortho and para hydrogen, a similar state of affairs in the case of iodine gas was demonstrated by direct experiment by R. W. Wood and F. W. Loomis.1 In brief, these experimenters found that the iodine bands observed in fluorescence stimulated by white light differ from those in the fluorescence excited by the green mercury line X 5461, which happens to coincide with one of the iodine absorption lines. Half of the lines are missing in the latter case, only those being present which are due to transitions in which the rotational quantum number of the upper state is an even integer. In other words, in the fluorescence spectrum excited by X 5461 only those lines appear which are due to what we may provisionally call the ortho type of iodine molecule. 

Iodine number a measure of the iodine absorption by an oil under standard conditions used to indicate the quantity of unsaturated compounds present also called iodine value. 

Fig. 4. Results of the absolute frequency measurements shown are the absolute frequencies and hyperfine line separation of the hyperflne components ai, aio and ais of the P(54)32-0 and the hyperflne component aio of the R,(56)32—0 iodine absorption line. Numbers in brackets correspond to an independent heterodyne frequency measurement where the beat between two ILP lasers, locked to corresponding HFS components of the P(54)32-0 and the R,(56)32-0 line, were observed (for details see text)...

Table VI shows the results of a number of these experiments, using different magnesium sulfate concentrations. The increase of fractionation efficiency with increase of the salt concentration is evident. Independent of the salt concentration, all experiments yield amylose fractions of maximum iodine-absorption capacity, as recrystallization with 1-butanol did not show any increase in the original values.

In other applications of CT, orally administered barium sulfate or a water-soluble iodinated CM is used to opacify the GI tract. Xenon, atomic number 54, exhibits similar x-ray absorption properties to those of iodine. It rapidly diffuses across the blood brain barrier after inhalation to saturate different tissues of brain as a function of its lipid solubility. In preliminary investigations (99), xenon gas inhalation prior to brain CT has provided useful information for evaluations of local cerebral blood flow and cerebral tissue abnormalities. Xenon exhibits an anesthetic effect at high concentrations but otherwise is free of physiological effects because of its nonreactive nature. 

ASTM number Iodine number DBP CTAB N2 absorption... 

The absorption potential of carbon is given by its iodine number (IN). The IN is a measure of how many milligrams of iodine, present in a 0.02 N iodine solution, can be adsorbed by 1 gram of carbon. Usually the IN is between 850 and 1,200. 

The major fatty acids present in plant-derived fatty substances are oleic acid (9-octadecenoic, C18 l), linoleic acid (9,12-octadecadienoic, C18 2) and the conjugated isomers thereof and linolenic acid (9,12,15-octadecatrienoic, C18 3) (Scheme 31.1). Their rates of oxygen absorption are 100 40 1, respectively, hence partial hydrogenation with consequent lowering of the iodine number would lead to a significant increase in oxidative stabihty, particularly when C18 3 is reduced. 

Benesi and Hildebrand (1949) investigated the absorption spectra of iodine in various solvents. On going to benzene and methylbenzenes, these authors found a new intense band in the region of between 270 and 400 m/x, which is not present in non-polar and saturated solvents (Kortiim and Friedhelm, 1947). These bands are bathochromically displaced as the number of methyl groups increases, whilst the absorption band in the visible region is simultaneously displaced hypso-chromically. 

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