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US5062991A
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In situ use of gelatin in the preparation of uniform ferrite particles
Assignee: Beckman Coulter Inc
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Filing: 1990-06-04
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Granted: 1991-11-05
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Expires: 2010-06-04
Abstract
Abstract A method is described for the preparation of uniform colloidal particles of ferrites, containing manganese (II), zinc(II), barium(II), iron(II), cobalt(II), or nickel(II), or a mixture of manganese(II) and zinc(II), at a relatively low temperature in the presence of a gelatin solution which acts as a support vehicle for the nucleation and growth of colloidal particles of metal oxide and for dispersion as separate single particles.
Inventors
- 👤 Olavi Siiman
- 👤 Alexander Burshteyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:34
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/0004; B01J13/0008; B01J13/0013; B03; B03C; B03C1/00; B03C1/005; B03C1/01; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/06; H01F1/061; H01F1/44; H01F1/445; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
117 words
A method of making colloidal ferrite particles of uniform size and shape comprising: A. mixing a first solution of potassium nitrate and potassium hydroxide or sodium nitrate and sodium hydroxide, respectively, which has been nitrogen gas purged and a B. second solution of a ferrous salt, divalent metal salt and a gelatin solution which second solution has been nitrogen purged; C. sweeping the gelatinous metal hydroxide mixture of the two solutions with nitrogen gas and ripening same to form a ferrite hydrosol at a predetermined low temperature for a selected period of time; D. washing the hydrosol with said gelatin solution by magnetic separation and redispersion, whereby to form separate single metal ferrite particles coated with gelatin.
Claim 2
Independent Claim
117 words
A method of making colloidal ferrite particles of uniform size and shape comprising: A. mixing a first solution of potassium nitrate and potassium hydroxide or sodium nitrate and sodium hydroxide, respectively, which has been nitrogen gas purged and a B. second solution of a ferrous salt, divalent metal salt and a gelatin solution which second solution has been nitrogen purged; C. sweeping the gelatinous metal hydroxide mixture of the two solutions with nitrogen gas and ripening same to form a ferrite hydrosol at a predetermined low temperature for a selected period of time; D. washing the hydrosol with said gelatin solution by magnetic separation and redispersion, whereby to form separate single metal ferrite particles coated with gelatin.
Claim 3
Dependent Claim
20 words
The method of claim 1 in which the metal ion of said divalent metal salt is the Fe2 + ion.
Claim 4
Dependent Claim
18 words
The method of claim 2 in which said ferrous salt can be either a chloride or sulfate salt.
Claim 5
Dependent Claim
34 words
The method of claim 1 in which the metal ion of said divalent metal salt is selected from the group consisting of Mr 2+ , Co2 + , Ni2 + and Zn2 + ions.
Claim 6
Dependent Claim
28 words
The method of claim 1 in which the metal ion of said divalent metal salt is selected from the mixed group of Mn2 + and Zn2 + ions.
Claim 7
Dependent Claim
27 words
The method of claim 4 in which said divalent metal salt is selected from the group consisting of a metal chloride, metal sulfate and metal nitrate salt.
Claim 8
Dependent Claim
25 words
The method of claim 5 in which said divalent metal salt is selected from a mixture of metal chloride, metal sulfate and metal nitrate salts.
Claim 9
Dependent Claim
18 words
The method of claim 6 in which said ferrous salt can be either a chloride or sulfate salt.
Claim 10
Dependent Claim
30 words
The method of claim 1 in which the divalent metal salt is selected from the group consisting of barium nitrate and barium chloride and the ferrous salt comprises ferrous chloride.
Claim 11
Dependent Claim
13 words
A colloidal ferrite particle produced by the method of claims 1 or 2.
Claim 12
Dependent Claim
53 words
Colloidal particles which are monodispersed having a ferrite structure and a mean particle diameter of approximately 0.1 to 1.0 microns, said particles including a divalent metal ion selected from the group consisting of manganese(II), zinc(II), mixed Mn(II)-Zn(II), iron(II), barium(II.), cobalt(II) and nickel(II) and characterized as being well-defined and of uniform size and shape.
Claim 13
Dependent Claim
53 words
Colloidal particles which are monodispersed having a ferrite structure and a mean particle diameter of approximately 0.1 to 1.0 microns, said particles including a divalent metal ion selected from the group consisting of manganese(II), zinc(II), mixed Mn(II)-Zn(II), iron(II), barium(II.), cobalt(II) and nickel(II) and characterized as being well-defined and of uniform size and shape.
Claim 14
Dependent Claim
25 words
The colloidal particles of claim 11 in which ferrite particles of manganese(II), zinc(ID, mixed manganese(II)-zinc(II) and barium(II) display a ferrimagnetic response to a magnetic field.
Claim 15
Dependent Claim
24 words
The colloidal particles of claim 11 in which the ferrite particles of iron(II), cobalt(II) and nickel(II) display a ferromagnetic response to a magnetic field.
References Cited (Backward Citations)
WO1988005337A1
Cited
US4965007A
Cited
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