Porous alumina-carbon based composite membrane and its fabrication method

Patent metadata

Field	Value
Publication number	US-2019336918-A1
Application number	US-201815971862-A
Country	US
Kind code	A1
Filing date	May 4, 2018
Priority date	May 4, 2018
Publication date	Nov 7, 2019
Grant date	—

Abstract

Durable, porous alumina-carbon nanotube membranes and methods for making them using spark plasma sintering. Methods for removing heavy metals such as cadmium from waste water using alumina-carbon nanotube membranes.

First claim

1 . A porous alumina-carbon nanotube membrane comprising at least about 90 wt. % Al 2 O 3 and between about 0.5 wt. % and about 5 wt. % carbon nanotubes.

2 . The porous alumina-carbon nanotube membrane of claim 1 that comprises a ceramic matrix comprising Al 2 O 3 .

3 . The porous alumina-carbon nanotube membrane of claim 1 that does not contain one or more of zircon, tin, phosphorous, magnesium, yttrium, barium, and/or tantalum.

4 . The porous alumina-carbon nanotube membrane of claim 1 that consists of sintered Al 2 O 3 and carbon nanotubes.

5 . The porous alumina-carbon nanotube membrane of claim 1 that is further functionalized by at least one ligand that binds to a metal.

6 . The porous alumina-carbon nanotube membrane of claim 1 that is produced by conventional sintering.

7 . The porous alumina-carbon nanotube membrane of claim 1 that is produced by uniaxially pressing the mixture and by pressureless sintering.

8 . The porous alumina-carbon nanotube membrane of claim 1 that is produced by sintering in a tube furnace and not by spark plasma sintering.

9 . The porous alumina-carbon nanotube membrane of claim 1 that is produced by spark plasma sintering (“SPS”).

10 . The porous alumina-carbon nanotube membrane of claim 1 that is produced by spark plasma sintering performed at a pressure of 5.6 to 20 MPa, a temperature of 1,000 to 1,200° C., a heating rate of 180 to 200° C./min, and a holding time of 2.5 to 10 mins.

11 . The porous alumina-carbon nanotube membrane of claim 1 that is formed by sintering a mixture of the Al 2 O 3 and carbon nanotubes and at least one pore former in an amount ranging from 0.1 to 10 wt. % and dispersant in an amount ranging from 0.1 to 10 wt. % of the mixture that is sintered.

12 . The porous alumina-carbon nanotube membrane of claim 1 that is formed by sintering a mixture of the Al 2 O 3 and carbon nanotubes and at least one pore former that is starch and dispersants that are gum Arabic and sodium dodecyl sulfate.

13 . A filter comprising the porous alumina-carbon nanotube membrane of claim 1 .

14 . The porous alumina-carbon nanotube membrane of claim 1 that is produced by hot pressing, by hot isostatic pressing, or by otherwise applying pressure and heat/temperature simultaneously to the mixture.

15 . A method for making a porous alumina-carbon nanotube membrane comprising sintering a mixture comprising at least 90 wt. % Al 2 O 3 and between about 0.5 wt. % and about 5 wt. % carbon nanotubes.

16 . The method of claim 15 , wherein the mixture comprises at least 90 wt. % Al 2 O 3 and between about 0.5 wt. % and about 5 wt. % carbon nanotubes and does not contain one or more of zircon, tin, phosphorous, magnesium, yttrium, barium, and/or tantalum.

17 . The method of claim 15 , wherein the mixture consists of at least 90 wt. % Al 2 O 3 and between about 0.5 wt. % and about 5 wt. % carbon nanotubes.

18 . The method of claim 15 , wherein the sintering comprises spark plasma sintering.

19 . The method of claim 15 , wherein the sintering consists of spark plasma sintering (SPS) performed at:
a pressure of 5.6 to 20 MPa, a temperature of 1,000 to 1,200° C., a heating rate of 50 to 200° C./min, and a holding time of 2.5 to 10 mins.

20 . The method of claim 15 , wherein the mixture is uniaxially pressed and then pressurelessly sintered.

21 . A method for removing a heavy or toxic metal from water comprising contacting an aqueous solution containing cadmium, which has a pH ranging from 5.5 to 8.5, by contacting the aqueous solution with a porous alumina-carbon nanotube membrane that comprises at least about 90 wt. % Al 2 O 3 and between about 0.5 wt. % and about 5 wt. % carbon nanotubes, and recovering water from which the heavy or toxic metal has been removed.

22 . The method of claim 21 , wherein the heavy metal is cadmium.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Laoui Tahar
• Shahzad Hafiz Khurram
• Hussein Mohamed Abdrabou

Classifications

• C04B38/00

  Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof (treating slag with gases or gas generating material C04B5/06 {; expanded graphite C04B35/536}) · CPC title

• C04B2235/668

  Pressureless sintering · CPC title

• C04B35/117

  Composites · CPC title

• C04B2235/526

  characterised by the length of the fibers · CPC title

• C04B2235/5445

  submicron sized, i.e. from 0,1 to 1 micron · CPC title