Layered double hydroxide particles in hydrogel matrices

Patent metadata

Field	Value
Publication number	US-2025128957-A1
Application number	US-202418985816-A
Country	US
Kind code	A1
Filing date	Dec 18, 2024
Priority date	Aug 20, 2021
Publication date	Apr 24, 2025
Grant date	—

Abstract

Exemplary layered double hydroxides (LDHs) may comprise a compound of formula Mg4−yAlXy(OH)2, wherein X is Mn+2, Cu+2, Zn+2, or Fe+2, and 0.01≤y≤1. Exemplary layered double hydroxide hydrogels (LDH-gels) may comprise a hydrogel and at least one LDH. Exemplary hydrogels may comprise polyethylene (glycol) diacrylate (PEGDA) or polyacrylamide (PAAm). Exemplary LDH-gels may comprise at least one LDH comprising a compound of formula Mg4−yAlXy(OH)2, wherein X is Mn+2, Cu+2, Zn+2, or Fe+2, and 0.01≤y≤1.

First claim

1 - 19 . (canceled)

20 . A method of preparing layered double hydroxide (LDH) particles, the method comprising:
preparing a metal ion solution comprising magnesium chloride (MgCl 2 ), aluminum chloride (AlCl 3 ), and a transition metal chloride (XCl 2 ); adding a 2 M sodium hydroxide (NaOH) solution to the metal ion solution to form a first suspension comprising the LDH particles; centrifuging the first suspension and decanting a first supernatant or filtering the LDH particles; exposing the LDH particles to a 2 M sodium carbonate (Na2CO3) solution to form a second suspension comprising the LDH particles; centrifuging the second suspension and decanting a second supernatant or filtering the LDH particles; washing the LDH particles; drying the LDH particles; and calcining the LDH particles.

21 . The method of claim 20 , wherein washing comprises a first washing step, a second washing step, and a third washing step, wherein:
the first washing step comprises washing the LDH particles with a solution comprising sodium carbonate (Na 2 CO 3 ), and the second and third washing steps comprise washing the LDH particles with pure water.

22 . The method of claim 20 , wherein the transition metal chloride is MnCl 2 , CuCl 2 , ZnCl 2 , or FeCl 2 .

23 . The method of claim 20 , wherein calcining the LDH particles occurs at a temperature of 350° C. to 550° C.

24 . The method of claim 20 , wherein the LDH particles comprise:
a compound of formula Mg 4−y AlX y (OH) 2 , wherein:
X is Mn +2 , Cu +2 , Zn +2 , or Fe +2 , and 0.01≤ y≤1.

25 . The method of claim 24 , wherein X is Zn +2 .

26 . The method of claim 24 , wherein X is Fe +2 .

27 . A method of making layered double hydroxide gel (LDH-gel), the method comprising:
forming a mixture, the mixture comprising:
a monomer,
a crosslinker,
a catalyst, and
LDH particles prepared according to claim 20 ;
adding an initiator to the mixture while stirring the mixture; allowing the mixture to form a solid; and washing the solid.

28 . The method of claim 27 , wherein after allowing the mixture to form a solid, and before washing the solid, the solid is broken into pieces.

29 . The method of claim 27 , wherein the method comprises:
forming the mixture in water; and adding the mixture in water to an oil to form a water-in-oil emulsion.

30 . The method of claim 29 , wherein the oil is paraffin oil.

31 . The method of claim 27 , wherein the monomer is acrylamide (AAm) or polyethylene (glycol) diacrylate (PEGDA).

32 . The method of claim 31 , wherein the PEGDA monomer has an average molecular weight of 575 g/mol.

33 . The method of claim 27 , wherein ammonium persulfate (APS) is the initiator.

34 . The method of claim 27 , wherein N,N,N′,N′-tetramethylethylenediamine (TEMED) is the catalyst.

35 . The method of claim 27 , wherein N,N′-methylenebisacrylamide (MBA) is the crosslinker.

36 . A filter, comprising an LDH-gel made according to the method of claim 27 .

Assignees

• Univ Duke

Inventors

• Trotochaud Lena Esters
• Sanchez Mariana Vasquez
• Kirillova Alina

Classifications

• C02F2101/105

  Phosphorus compounds · CPC title

• C02F1/288

  using composite sorbents, e.g. coated, impregnated, multi-layered · CPC title

• C02F1/281

  using inorganic sorbents · CPC title

• C02F2103/001

  Runoff or storm water · CPC title

• C01P2004/01

  depicted by an image · CPC title