| 释义 |
pervaporation Chem.|pəvæpəˈreɪʃən|
[f. permeation + evaporation.]
The evaporation of a liquid through a semi-permeable membrane with which it is in contact.
1917P. A. Kober in Jrnl. Amer. Chem. Soc. XXXIX. 944 My assistant..called my attention to the fact that a liquid in a collodion bag, which was suspended in the air, evaporated, although the bag was tightly closed... Further experiments..soon forced us to the conclusion that the aqueous vapor is given off through the membrane, as though the water were suspended as a solid without any membrane present. This phenomenon we have named pervaporation. 1934H. N. Holmes Introd. Colloid Chem. ii. 19 Dilute hydrochloric acid solutions were concentrated by pervaporation to the acid of constant boiling point. 1956Science 13 July 77/2 We have used pervaporation to dehydrate mashed potatoes. 1964New Scientist 26 Nov. 591/1 For the separation of mixtures of non-ionic liquids considerable interest is being shown in what is called the method of ‘pervaporation’ using thin polymer films. 1968Encycl. Polymer Sci. & Technol. VIII. 629 In pervaporation a mixture of liquids, often heated, on the upstream side of a membrane is driven through the film by a vacuum applied to the downstream side.
Hence perˈvaporate v. trans. and intr., to evaporate in this way; perˈvaporated, perˈvaporating ppl. adjs.
1917Jrnl. Amer. Chem. Soc. XXXIX. 944 After fanning these containers with an ordinary office fan for 24 hours the aqueous layer had pervaporated to dryness. Ibid. 945 The pervaporating surface decreased with the sinking of the water level. Ibid. 947 A similar container was filled with..sodium chloride solution and pervaporated. 1934H. N. Holmes Introd. Colloid Chem. ii. 18 A protein digestion residue containing strong hydrochloric acid, histidine, and enough humin to make it black was pervaporated. 1956Science 13 July 77/3 The filtrate from a mixture of mashed potato, ethanol, and water was pervaporated... In pervaporating solutions containing class-I solutes, the percentage of water in the pervaporated vapor varied somewhat. |