Composite for electrochemical gas separation
A composite includes a nonwoven carbon nanotube mat and an electroactive species disposed on the nonwoven carbon nanotube mat, wherein the electroactive species is capable of bonding with a target gas when the electroactive species is in a reduced state and releasing the target gas when the electroactive species is in an oxidized state. Electrode assemblies, electro-chemical cells, and gas separation systems including the composite are also described herein.
1 . A composite consisting of:
a nonwoven carbon nanotube mat consisting of
a plurality of entangled carbon nanotubes, each carbon nanotube of the plurality of entangled carbon nanotubes having an average diameter of 50 nanometers or less, and an average length of 50 micrometers to 2 millimeters;
optionally, graphene, reduced graphene oxide, carbon black, Ketjen black, or structured carbon black;
optionally, a polymer binder; and
an electroactive species disposed on the nonwoven carbon nanotube mat, wherein the electroactive species is capable of bonding with a target gas when the electroactive species is in a reduced state and releasing the target gas when the electroactive species is in an oxidized state.
2 . The composite of claim 1 , wherein the composite has a porosity of at least 20%.
3 . The composite of claim 1 , wherein the carbon nanotubes comprise single wall carbon nanotubes, multiwall carbon nanotubes, or a combination thereof.
4 . The composite of claim 1 , wherein the composite has a thickness of less than 100 micrometers.
5 . The composite of claim 1 , wherein the electroactive species is on a surface of the nonwoven carbon nanotube mat.
6 . The composite of claim 1 , wherein electroactive species is on a surface of a carbon nanotube of the nonwoven carbon nanotube mat.
7 . The composite of claim 1 , wherein the electroactive species comprises an electroactive polymer, an electroactive oligomer, an electroactive organic compound, an electroactive inorganic complex, an electroactive organometallic complex, or a combination thereof.
8 . The composite of claim 1 , wherein the electroactive species comprises an electroactive polymer, an electroactive oligomer, an electroactive organic compound, or a combination thereof.
9 . The composite of claim 1 , wherein the electroactive species comprises
a substituted or unsubstituted quinone or tetrone; or
a polymer or oligomer comprising repeating units derived from a substituted or unsubstituted quinone or tetrone.
10 . The composite of claim 1 , wherein a content of the electroactive species is 10 to 90 weight percent, based on total weight of the composite.
11 . The composite of claim 1 , wherein a thickness of the electroactive species on the surface of the carbon nanotubes of the carbon nanotube mat is 0.1 to 20 nanometers.
12 . The composite of claim 1 , wherein the electroactive species has a binding constant with the target gas of at least 10 1 M 1 .
13 . The composite of claim 1 , wherein the electroactive species comprises the electroactive polymer or the electroactive oligomer, and the electroactive polymer or the electroactive oligomer are crosslinked.
14 . The composite of claim 1 , wherein the electroactive species is covalently attached to the nonwoven carbon nanotube mat.
15 . The composite of claim 1 , wherein the target gas comprises a Lewis acid gas.
16 . An electrode assembly comprising:
a porous separator; and
the composite of claim 1 .
17 . An electrochemical cell comprising the composite of claim 1 .
18 . The electrochemical cell of claim 17 , comprising
a first electrode comprising the composite of claim 1 ;
a second electrode comprising a complementary electroactive composite layer; and
a first separator between the first electrode and the second electrode.
19 . The electrochemical cell of claim 17 , wherein the composite further comprises an electrolyte.
20 . A gas separation system comprising:
a plurality of electrochemical cells in fluid communication with a gas inlet and a gas outlet, wherein each of the plurality of electrochemical cells is according to claim 17 .
21 . A method of making the composite of claim 1 , the method comprising contacting the nonwoven carbon nanotube mat with the electroactive species.
22 . The method of claim 21 , wherein contacting the nonwoven carbon nanotube mat with the electroactive species comprises contacting a solution consisting of the electroactive species with the nonwoven carbon nanotube mat or contacting a vapor phase consisting of the electroactive species with the nonwoven carbon nanotube mat.
23 . The method of claim 22 , wherein the electroactive species comprises an electroactive polymer, an electroactive oligomer, or a combination thereof and the method further comprises crosslinking the electroactive polymer or the electroactive oligomer.
24 . A method of making the composite of claim 1 , the method comprising
contacting a solution consisting of a plurality of electroactive monomers, at least one initiator, and optionally, a crosslinker with the nonwoven carbon nanotube mat; and
initiating polymerization in the presence of the nonwoven carbon nanotube mat.