Magnetic cellulose-derivative structures
AssigneeCape Cod Research, Inc.
InventorsMyles A. Walsh, Robert S. Morris
Life of this patent
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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.
Claims17
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.
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.
Dependencies are inferred from the claim text.