| 释义 |
ion exchange
The interchange of ions of like charge between an insoluble solid and a solution in contact with it. Freq. attrib. (usu. hyphenated), as ion-exchange resin, any synthetic resin or polymer suitable for use as an ion exchanger, characterized in general by a cross-linked molecular network which allows the penetration of solvent and ions (causing swelling) and has ionized or ionizable groups weakly attached to it.
1923Chem. Abstr. XVII. 578 (heading) The ion exchange between the blood corpuscles and the serum. 1943Industr. & Engin. Chem. Aug. 858 (heading) Ion exchange resins. New tools for process industries. 1946Jrnl. Amer. Leather Chemists' Assoc. XLI. 555 The present work is an attempt to explore the possibilities of utilizing ion exchange resins in the analysis of some chromium liquors of various types. 1949[see ion exchanger below]. 1950Sci. Amer. Nov. 51/3 Ion exchange has provided a tool for fascinating studies of the constituents of cell nuclei—nucleic acids and nucleotides—which are so similar to one another that they are nearly impossible to separate by conventional means. 1951J. E. Maudru in R. A. McGinnis Beet-Sugar Technol. x. 289 Ion exchange..is another type of juice purification which has recently been applied to the beet-sugar industry. This process consists of passing dilute juice..through beds of active synthetic resinous material, which removes ionized impurities. 1952Sci. News XXVI. 83 Ion-exchange resins are usually marketed in the form of coarse or spherical granules, about 1–2 millimetres in diameter... The major use of these resins is in the complete removal of salts from water by ion-exchange. 1963Guardian 28 Feb. 18/1 The Government had decided to establish an experimental pilot plant to examine the problems in the removal of strontium 90 from milk by an ion-exchange process. 1964Oceanogr. & Marine Biol. II. 149 The amino acid compositions of phytoplankton and pure cultures of phytoplanktonic species have been determined by paper chromatography and by ion-exchange chromatography.
Also ion exchanger, a solid involved or used in ion exchange; also, an apparatus for effecting ion exchange.
1941Jrnl. Franklin Inst. CCXXXII. 317 It is possible..that the characteristics of an ion exchanger are conditioned by the nature of the ion with which it was last saturated. 1949H. F. Walton in F. C. Nachod Ion Exchange 4 In the materials which find practical use as ion exchangers, such as the synthetic aluminosilicates, synthetic resins, or sulfuric acid-treated coals, nearly all of the ion exchange takes place in the interior of the granules, which have a gel structure, something like a sponge on the molecular scale. 1950Sci. Amer. Nov. 50/2 During the war compact little ion exchangers were used in life-raft emergency kits for making drinking water from sea water. 1960R. Kunin Elem. Ion Exchange iii. 24 Only the zeolite minerals have a sufficiently satisfactory combination of the above-mentioned characteristics..to permit their use as ion exchangers on a commercial scale. |