US4612247A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic cellulose-derivative structures
Assignee: Cape Cod Research Inc
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Filing: 1984-06-27
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Granted: 1986-09-16
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Expires: 2004-06-27
Abstract
Abstract Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorbtion agents can be incorporated during the manufacture of the structure.
Inventors
- 👤 Myles A. Walsh
- 👤 Robert S. Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:46
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/28; B01J20/28002; B01J20/28004; B01J20/28009; B01J20/28014; B01J20/28016; B01J20/28019; B01J20/28026; B01J20/2805; B01J20/28054; B01J20/28095; B01J20/28097; B03; B03C; B03C1/00; B03C1/005; B03C1/01; C; C02; C02F; C02F1/00; C02F1/48; C02F1/488; C12; C12N; C12N11/00; C12N11/02; C12P; C12P7/00; C12P7/02; C12P7/04; C12P7/06; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/5434; G01N2400/00; G01N2400/10; G01N2400/12; G01N2400/24; G01N2400/26; G01N2446/00; G01N2446/20; G01N2446/30; Y; Y02; Y02E; Y02E50/00; Y02E50/10; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249994; Y10T428/249995; Y10T428/249997; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
97 words
A porous magnetic structure containing at least one reactive agent comprising: (a) a shell formed of a microporous water-insoluble cellulose derivative, having a microporous matrix, the shell ranging in diameter from 5 to 1000 microns; (b) one or more magnetic particles having diameters of less than 50 microns and which are encapsulated in the shell in an amount of at least 0.1 percent by weight of the shell; and (c) at least one reactive agent supported within the microporous matrix of the cellulose derivative shell, for selectively extracting specific materials from the aqueous solution to be treated.
Claim 2
Dependent Claim
97 words
A porous magnetic structure containing at least one reactive agent comprising: (a) a shell formed of a microporous water-insoluble cellulose derivative, having a microporous matrix, the shell ranging in diameter from 5 to 1000 microns; (b) one or more magnetic particles having diameters of less than 50 microns and which are encapsulated in the shell in an amount of at least 0.1 percent by weight of the shell; and (c) at least one reactive agent supported within the microporous matrix of the cellulose derivative shell, for selectively extracting specific materials from the aqueous solution to be treated.
Claim 3
Dependent Claim
46 words
A structure according to claim 1 in which the microporous cellulose derivative is water-insoluble and has a porosity of between 60 and 90 percent, and is selected from at least one member of the group consisting of cellulose triacetate, cellulose nitrate, cellulose tripropionate, and ethyl cellulose.
Claim 4
Dependent Claim
33 words
A structure according to claim 1 in which the magnetic particles are selected from at least one member of the group consisting of magnetite, barium ferrite, cobalt ferrite, nickel, and magnetic stainless steel.
Claim 5
Dependent Claim
15 words
A structure according to claim 1 in which the reactive agent is an ion-selective agent.
Claim 6
Dependent Claim
15 words
A structure according to claim 1 in which the reactive agent is an organic-selective agent.
Claim 7
Independent Claim
60 words
A method for forming sorbent magnetic structures comprising the steps of: (a) forming a solution by dissolving at least one cellulose derivative in a first solvent; (b) blending a fine powder of magnetic particles into the cellulose-derivative solution to form a slurry; (c) spraying the slurry in the form of a fine mist; and (d) collecting a resulting magnetic structure.
Claim 8
Independent Claim
60 words
A method for forming sorbent magnetic structures comprising the steps of: (a) forming a solution by dissolving at least one cellulose derivative in a first solvent; (b) blending a fine powder of magnetic particles into the cellulose-derivative solution to form a slurry; (c) spraying the slurry in the form of a fine mist; and (d) collecting a resulting magnetic structure.
Claim 9
Dependent Claim
40 words
The method according to claim 6 in which the mist settles into a second solvent liquid coagulant wherein the coagulent is selected from those liquids in which the cellulose derivatives are insoluble but in which the first solvent is soluble.
Claim 10
Dependent Claim
59 words
The method according to claim 7 in which the first solvent is selected from at least one member of the group consisting of toluene, diethyl ether, and a low-molecular-weight chlorinated alkane, and the second solvent coagulant is selected from at least one member of the group consisting of water, a lower alcohol, a low-boiling alkane, glycerin, and petroleum ether.
Claim 11
Dependent Claim
31 words
The method according to claim 6 in which the cellulose derivative is selected from at least one member of the group consisting of cellulose triacetate, cellulose tripropionate, cellulose nitrate, and ethylcellulose.
Claim 12
Dependent Claim
41 words
The method according to claim 6 in which the structures are in the form of microspheres containing from 0.1 to 90% magnetic material, having a diameter of from 5 to 1000 microns, and having a porosity of from 60 to 90%.
Claim 13
Dependent Claim
36 words
The method according to claim 6 further comprising dissolving a sorbent solid in a second solvent, wherein said second solvent is soluble in the first solvent, and adding the sorbent solution to the magnetic particle slurry.
Claim 14
Dependent Claim
20 words
The method according to claim 11 in which the sorbent solid comprises carnuba wax and the second solvent comprises chloroform.
Claim 15
Dependent Claim
22 words
The method according to claim 6 further comprising the step of filling the sorbent magnetic structures with one or more ion-selective agents.
Claim 16
Dependent Claim
20 words
The method according to claim 13 in which filling is accomplished by soaking the porous structures in an ion-selective liquid.
Claim 17
Dependent Claim
42 words
The method according to claim 13 in which filling is accomplished by soaking the porous structures in a solution of alcohol and titanium tetrachloride, and further comprising the steps of removing the structures magnetically and washing the structures in concentrated ammonium hydroxide.
Claim 18
Dependent Claim
46 words
The method according to claim 13 in which filling is accomplished by soaking the porous structures in a nutrient broth containing microorganisms, and further comprising the steps of removing the structures magnetically and allowing the growth of the microorganisms within the pores of the magnetic structures.
Claim 19
Dependent Claim
40 words
The method according to claim 13 in which filling is accomplished by soaking the porous structures in a nutrient broth containing microorganisms and further comprising the step of allowing the growth of microorganisms within the pores of the magnetic structures.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-15 | 1990-03-17 | 1990-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-15 | 1994-03-17 | 1994-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-15 | 1998-03-17 | 1998-09-16 | $7700.00 | Window Closed / Lapsed |