Compositions and methods for direct capture of organic materials from process streams

Patent metadata

Field	Value
Publication number	US-9409148-B2
Application number	US-201313962480-A
Country	US
Kind code	B2
Filing date	Aug 8, 2013
Priority date	Aug 8, 2013
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A particulate magnetic nanostructured solid sorbent (MNSS) material is described herein. The particles of the MNSS comprise a plurality of tethered nanoparticles. The nanoparticles are tethered together by substantially linear hydrocarbon chains, a poly(alkylene oxide) chains, or a combination thereof connecting the nanoparticles in a three-dimensional elastic network with the nanoparticles as junctions of the network having junction functionality of about 2.1 to about 6. The surfaces of at least some of the nanoparticles comprise a polymerized siloxane bearing at least one sorption-aiding substituent selected from a hydrophilic group and a lipophilic group. The plurality of nanoparticles is made up of superparamagnetic nanoparticles or a combination of superparamagnetic and non-magnetic nanoparticles. The individual superparamagnetic nanoparticles comprise a passivating metal oxide coating around a core comprising at least one nanocrystalline metal or alloy having ferromagnetic or ferrimagnetic properties.

First claim

What is claimed is:

1. A particulate magnetic nanostructured solid sorbent (MNSS) material comprising a plurality of particles, each particle of the MNSS comprising a plurality of nanoparticles tethered together by molecular chains having at least two ends per chain, each chain comprising a substantially linear hydrocarbon, a poly(alkylene oxide), or a combination thereof, the ends of the chains connecting the nanoparticles in a three-dimensional elastic network; wherein the network has a junction functionality of about 2.1 to about 6, with the nanoparticles as junctions of the network; a surface of at least some of the nanoparticles comprises a polysiloxane bearing sorption-aiding substituents selected from hydrophilic substituents, lipophilic substituents, and a combination thereof; the plurality of nanoparticles comprises superparamagnetic nanoparticles or a combination of superparamagnetic and non-magnetic nanoparticles; the superparamagnetic nanoparticles comprise nanocrystalline metallic cores with a passivating metal oxide coating around each core; and the nanocrystalline metallic cores have ferromagnetic or ferrimagnetic properties.

2. The particulate MNSS material of claim 1 wherein the nanocrystalline metallic cores are substantially spherical.

3. The particulate MNSS material of claim 1 wherein the nanocrystalline metallic cores of the superparamagnetic nanoparticles comprise metallic Fe, Co, or a combination thereof.

4. The particulate MNSS material of claim 1 wherein the superparamagnetic nanoparticles have a mean diameter of about 0.5 nm to about 100 nm.

5. The particulate MNSS material of claim 1 wherein the superparamagnetic nanoparticles have a mean diameter of about 2 nm to about 50 nm.

6. The particulate MNSS material of claim 2 wherein the non-magnetic nanoparticles comprise substantially spherical nanocrystalline particles.

7. The particulate MNSS material of claim 6 wherein the non-magnetic nanoparticles have a mean diameter of about 2 nm to about 50 nm.

8. The particulate MNSS material of claim 1 wherein the ends of the chains are bonded to the surfaces of the nanoparticles or to the polysiloxane through a silicon-to-oxygen bond.

9. The particulate MNSS material of claim 1 wherein the particles of the particulate MNSS have a mean diameter of about 0.1 to 1,000 microns.

10. The particulate MNSS material of claim 1 wherein the particles of the particulate MNSS have a mean diameter of about 50 to 300 microns.

11. The particulate MNSS material of claim 1 wherein the non-magnetic nanoparticles comprise a metal oxide.

12. The particulate MNSS material of claim 1 wherein the surfaces of at least some of the nanoparticles comprise a polysiloxane bearing hydrophilic substituents.

13. The particulate MNSS material of claim 1 wherein the surfaces of at least some of the nanoparticles comprise a polysiloxane bearing lipophilic substituents.

14. The particulate MNSS material of claim 1 wherein the polysiloxane bears substituent groups independently selected from the group consisting of amino, hydroxyl, mercapto, alkoxy, saturated or unsaturated alkyl, cycloalkyl, aryl and heteroaryl, in which the alkyl, cycloalkyl, aryl, and heteroaryl groups can be unsubstituted, or can be substituted with one or more suitable substituent selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, amino, hydroxyl, mercapto, alkoxy, a carboxylic acid, a phosphonic acid, a sulfonic acid, a carboxylic ester, a carboxylic amide, a carboxylic anhydride, a saccharide (sugar), a halogen, and or a salt of any of the foregoing groups that is ionizable.

15. The particulate MNSS material of claim 1 wherein the passivating metal oxide coating comprises a silicon oxide or aluminum oxide material.

16. A method of separating a target organic compound from a liquid medium, the method comprising the steps of:
(a) contacting the liquid medium containing the target organic compound with the MNSS material of claim 1 for a time sufficient to sorb at least a portion of the target organic compound from the aqueous fluid to form a MNSS-target compound complex; and
(b) separating the complex from the aqueous fluid via magnetic separation.

17. The method claim 16 wherein the aqueous fluid contains less than 15 wt % of the target organic compound prior to contacting with the MNSS material.

18. The method claim 16 wherein the magnetic separation comprises magnetocollection, magnetoflocculation, or magnetoanisotropic sorting.

19. The method claim 16 including the additional step (c) of recovering the target organic compound from the MNSS material following step (b) by one or more of the following processes: magnetostriction, pH shock, thermal shock, mechanical deformation, or solvent extraction.

20. A method of preparing the MNSS material of claim 1 comprising the steps of:
(a) heating a mixture comprising nanoparticles, a coupling agent, and a polymerizable siloxane monomer, and optionally a solvent, at a temperature and in relative quantities sufficient for the coupling agent to tether the nanoparticles to a selected degree of junction functionality of about 2.1 to about 6, and for the siloxane monomer to form a polysiloxane on the surface or in the surface proximity of the nanoparticles, thereby forming the particulate MNSS material; and
(b) optionally removing any volatile by-products or solvent from the MNSS material;
wherein the nanoparticles comprise superparamagnetic nanoparticles or a combination of superparamagnetic nanoparticles and non-magnetic nanoparticles; the superparamagnetic nanoparticles comprise nanocrystalline metallic cores with a passivating metal oxide coating around each core; and the nanocrystalline metallic cores have ferromagnetic or ferrimagnetic properties; the coupling agent comprises a substantially linear hydrocarbon chain, poly(alkylene oxide) chain, or a combination thereof, each chain has at least two ends, and the ends of the chains include functional groups capable of covalently bonding with the nanoparticles; and the polymerizable siloxane monomer bears one or more hydrophilic substituent, lipophilic substituent, or a combination of hydrophilic and lipophilic substituents.

Assignees

• Uchicago Argonne Llc

Inventors

• Lin Yupo J
• Brotzman Richard W
• Snyder Seth W

Classifications

• B01J20/28009

  Magnetic properties · CPC title

• B01J20/3293 Primary

  Coatings on a core, the core being particle or fiber shaped, e.g. encapsulated particles, coated fibers · CPC title

• B01J20/28007

  with size in the range 1-100 nanometers, e.g. nanosized particles, nanofibers, nanotubes, nanowires or the like (carbon nanostructures B01J20/205) · CPC title

• B01J20/3285

  Coating or impregnation layers comprising different type of functional groups or interactions, e.g. different ligands in various parts of the sorbent, mixed mode, dual zone, bimodal, multimodal, ionic or hydrophobic, cationic or anionic, hydrophilic or hydrophobic · CPC title

• B01J20/0225

  Compounds of Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt · CPC title