Method of purifying metal oxide particles and uses thereof

Patent metadata

Field	Value
Publication number	US-11267723-B2
Application number	US-201716333691-A
Country	US
Kind code	B2
Filing date	Sep 8, 2017
Priority date	Sep 15, 2016
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A method of purifying a plurality of metal oxide particles produced from a synthesis process comprising the step of washing a plurality of metal oxide particles in a first solvent composition comprising of at least one aliphatic ether, and at least one flocculant. In one embodiment, the plurality of metal oxide particles are iron oxide particles produced from a thermal decomposition synthesis process between an iron-oleate complex and oleic acid in 1-octadecene, wherein the first solvent composition comprises a 1:1 (vol/vol) ratio of an aliphatic ether in the form of diethyl ether and a flocculant in the form of methanol. The washed iron oxide particles are further washed in a second solvent composition comprising a 1:1 (vol/vol) ratio of hexane and ethanol, and then finally dispersed in hexane. The resulting iron oxide particles find use as a contrast agent for magnetic resonance imaging (MRI) or as magnetic particles in magnetic separation, magnetism-directed targeting or magnetism-induced heating.

First claim

The claims defining the invention are as follows:

1. A method of purifying a plurality of metal oxide particles produced from a synthesis process, the method comprising the step of:
a) washing a plurality of metal oxide particles in a first solvent composition comprising:
i) at least one aliphatic ether; and
ii) at least one flocculant;
wherein the at least one aliphatic ether and the at least one flocculant are in a ratio of about 1:1 (vol/vol).

2. The method according to claim 1 , wherein the at least one aliphatic ether is at least partially miscible with the at least one flocculant.

3. The method according to claim 1 , wherein the at least one aliphatic ether is selected from the group consisting of diethyl ether, di-n-propyl ether, tert-butyl methyl ether and di-n-octyl ether.

4. The method according to claim 1 , wherein the at least one flocculant is selected from the group consisting of an alcohol, an aldehyde and a ketone.

5. The method according to claim 4 , wherein the alcohol is selected from the group consisting of methanol, ethanol and n-propanol.

6. The method according to claim 1 , wherein the at least one aliphatic ether is diethyl ether and the at least one flocculant is methanol.

7. The method according to claim 1 , wherein the first solvent composition further comprises at least one non-polar solvent.

8. The method according to claim 7 , wherein the at least one aliphatic ether and the at least one non-polar solvent are at least partially miscible with the at least one flocculant.

9. The method according to claim 7 , wherein the at least one aliphatic ether, the at least one non-polar solvent and the at least one flocculant are in a 1:1:2 (vol/vol) ratio.

10. The method according to claim 1 , further comprising, after step a), the step of:
b) further washing said plurality of washed metal oxide particles in a second solvent composition comprising of:
i) at least one non-polar solvent; and
ii) at least one flocculant.

11. The method according to claim 10 , wherein the at least one non-polar solvent is at least partially miscible with the at least one flocculant.

12. The method according to claim 10 , wherein the at least one non-polar solvent and the at least one flocculant are in a 1:1 (vol/vol) ratio.

13. The method according to claim 10 , wherein the at least one non-polar solvent is hexane and the at least one flocculant is ethanol.

14. The method according to claim 10 , further comprising, after step a) but before step b), the step of:
a1) separating the plurality of washed metal oxide particles from the first solvent composition using a physical separation procedure,
wherein the physical separation procedure is selected from the group consisting of magnetic separation, centrifugation, filtration and decantation.

15. The method according to claim 10 , further comprising, after step b), the step of:
c) dispersing said plurality of further washed metal oxide particles in a third solvent composition comprising:
i) at least one non-polar solvent.

16. The method according to claim 15 , further comprising, after step b) but before step c), the step of:
b1) separating the plurality of further washed metal oxide particles from the second solvent composition using a physical separation procedure;
wherein the physical separation procedure is selected from the group consisting of magnetic separation, centrifugation, filtration and decantation.

17. The method according to claim 1 , wherein purifying the plurality of metal oxide particles includes purifying a plurality of iron oxide particles.

18. The method according to claim 17 wherein the method comprises the steps of:
a) washing the plurality of iron oxide particles in a first solvent composition comprising of diethyl ether and methanol in a 1:1 (vol/vol) ratio;
b) further washing said plurality of washed iron oxide particles in a second solvent composition comprising hexane and ethanol in a 1:1 (vol/vol) ratio; and
c) dispersing said plurality of washed iron oxide particles in hexane.

19. A method according to claim 18 further comprising, after step a) but before step b), the step of:
a1) separating the plurality of washed iron oxide particles from the first solvent composition using a physical separation procedure; or

further comprising, after step b) but before step c), the step of:
b1) separating the plurality of further washed iron oxide particles from the second solvent composition using a physical separation procedure; or

further comprising steps a1) and b1).

Assignees

• Melbourne Inst Tech

Inventors

• Anderson Amanda
• Bansal Vipul
• Campbell Jos Laurie
• Ramanathan Rajesh
• Arora Jyoti
• Shukla Ravi

Classifications

• C01P2004/04

  obtained by TEM, STEM, STM or AFM · CPC title

• A61K49/06

  Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations · CPC title

• C01B13/16 Primary

  Purification · CPC title

• B01D21/01

  using flocculating agents (for purifying water C02F1/52; for liquid radioactive waste G21F9/10) · CPC title

• A61K49/1818

  particles, e.g. uncoated or non-functionalised microparticles or nanoparticles · CPC title