| 摘要 |
Sols comprising an actinide metal oxide in water or deuterium oxide may be prepared by removing the solubilising ions (v.i.) from a solution in water or deuterium oxide of an actinide metal compound by means of an ion exchange resin or by electrodialysis (see Group XXXVI). The invention also comprises an actinide metal oxide sol in water or deuterium oxide in which at least 80% of the particles have a diameter of 10-200 millimircrons, and it is stated that such sols may be obtained additionally by precipitation-peptization followed by fractional centrifuging. An example is provided of a sol prepared by means of a solution of tri-iso-octylamine functioning as an ion exchanger. By "solubilising ion" is meant the anion of a simple actinide metal salt or the cation of a salt in which the actinide metal is part of a complex anion (formed e.g. by addition of sodium or ammonium carbonate to a salt or other compound). Activide metals referred to are thorium, uranium, neptunium, plutonium, americium, curium and berkelium and the sols may contain one or more of these elements in one or more isotopic forms, details of preferred proportions being given. The sols may be suitable for use in nuclear reactors (see Group XL(a)) and may be stable at up to 375 DEG C. The Specification gives examples of strongly and weakly ionised exchangers of acidic and basic type which may be used in preparing the sols and gives details of preferred temperatures which are within the range room temperature to 150 DEG C., preferred pH conditions, and preferred procedures which lead to the initial production of seed nuclei and subsequent growth either as a single stage or two stage process: the seed nuclei may be provided by a silica sol. The sols may be stabilised by autoclaving, e.g. at 200 DEG -300 DEG C. or by adding, or forming in situ, a colloidal solution of silica and/or zirconium and aluminium oxides or one or more of iron, chromium, vanadium or nickel oxides. Specifications 720,002 and 821,229 and U.S.A. Specification 2,732,350 are referred to.ALSO:Membranes suitable for electrodialysis are obtained by casting films on reinforcing materials (see Group VIII) from liquids prepared (a) by dissolving 2-vinyl pyridine (containing 0,1% hydroquinone) in isopropanol, adding dimethyl sulphate, cooling and adding divinyl benzene (these reagents being used in roughly equal quantities) and (b) by melting together roughly equal quantities of phenol and resorcinol, cooling, sulphonating by adding sulphuric acid, cooling again and adding water to produce a mixture which is added slowly to about three times the quantity of aqueous 37% formaldehyde solution cooled to -10 DEG C. Specifications 720,009 and 821,229 and U.S.A. Specification 2,732,350 are referred to.
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