Hybrid ultramicroporous materials for water capture and release
A method of capturing water from a composition comprising water or water vapour using a hybrid ultramicroporous material. The method comprises the steps of: (a) providing a hybrid ultramicroporous material of formula [M(L)a(X)b]; and (b) contacting the hybrid ultramicroporous material with the composition comprising water to capture water into the hybrid ultramicroporous material; The hybrid ultramicroporous materials used in the method of the present invention have fast kinetics of water uptake and high working capacity compared to known commercial sorbent materials. The method of the present invention may be used in water capture and purification processes to provide fresh water suitable for drinking or for use in agriculture. The method of the present invention may also be used to remove water as a contaminant or for use in dehumidification processes. A use of such a hybrid ultramicroporous material and a device for capturing water are also disclosed.
1 . A method of capturing water from a composition comprising water and/or water vapour, the method comprising:
(a) providing a hybrid ultramicroporous material of formula [M(L)a(X)b];
(b) contacting the hybrid ultramicroporous material with the composition comprising water to capture water into the hybrid ultramicroporous material; and
(c) desorbing water from the hybrid ultramicroporous material as water vapour by either:
contacting the hybrid ultramicroporous material with an air stream having a temperature of at least 40° C.; or
applying a vacuum to the hybrid ultramicroporous material,
wherein:
M is a metal species selected from zinc, cadmium, copper, magnesium, cobalt, nickel, calcium and iron;
L is a ligand comprising a N-containing heterocycle;
X is a halogen linking species;
a is from 0.5 to 3; and
b is from 1 to 3.
2 . The method according to claim 1 wherein M is zinc.
3 . The method according to claim 1 wherein X is fluoride.
4 . The method according to claim 1 wherein L is 1,2,4-triazole or 3-amino-1,2,4-triazole.
5 . The method according to claim 1 wherein the composition is a gaseous composition comprising water.
6 . The method according to claim 1 wherein the composition is a liquid composition comprising water.
7 . The method according to claim 1 comprising the further step (d) of condensing the desorbed water vapour to provide liquid water.
8 . A method of delivering water to a locus from a composition comprising water or water vapour, the method comprising the steps of:
(i) providing a hybrid microporous material of formula [M(L)a(X)b];
(ii) contacting the hybrid microporous material with water or water vapour to capture water into the hybrid ultramicroporous material;
(iii) transporting and/or storing the hybrid microporous material;
(iv) applying a stimulus to the hybrid microporous material to effect desorption of water retained therein by either
contacting the hybrid ultramicroporous material with air having a temperature of at least 40° C.; or
applying a vacuum to the hybrid ultramicroporous material; and
(v) collecting desorbed water at the locus;
wherein:
M is a metal species selected from zinc, cadmium, copper, magnesium, cobalt, nickel, calcium and iron;
L is a ligand comprising a N-containing heterocycle;
X is a halogen linking species;
a is from 0.5 to 3; and
b is from 1 to 3.
9 . The method according to claim 1 wherein at least 12 wt % of water, based on the weight of the hybrid ultramicroporous material, is captured in 5 minutes.
10 . The method according to claim 1 wherein at least 2,000 wt % of water per day, based on the weight of the hybrid ultramicroporous material, is captured.
11 . The method according to claim 4 wherein L is 1,2,4-triazole.
12 . The method according to claim 5 wherein the composition is air.
13 . The method according to claim 6 wherein the composition is salted water and/or waste water.