Curable compositions and membranes
A composite membrane comprising: a) a porous support; b) a gutter layer, a portion of which is present within the support and a portion of which is outside of the support; and c) a discriminating layer on the gutter layer; wherein: (i) the portion of the gutter layer outside of the support has an average thickness (GL e ) of 10 nm to 900 nm; and (ii) the portion of the gutter layer present within the support has an average thickness (GL i ) of 10% to 350% of GL e .
1. A composite membrane comprising:
a) a porous support;
b) a gutter layer, a portion of which is present within the support and a portion of which is outside of the support; and
c) a discriminating layer on the gutter layer;
wherein:
(i) the portion of the gutter layer outside of the support has an average thickness (GL e ) of 10 nm to 900 nm; and
(ii) the portion of the gutter layer present within the support has an average thickness (GL i ) of 10% to 350% of GL e .
2. The composite membrane according to claim 1 wherein GL e has a value of from 400 to 900 nm.
3. The composite membrane according to claim 1 , wherein GL i has a value of 20% to 90% of GL e .
4. The composite membrane according to claim 1 , wherein the gutter layer comprises dialkoxysilane groups.
5. The composite membrane according to claim 1 , wherein the discriminating layer comprises a polyimide, cellulose acetate, polyethyleneoxide or polyetherimide.
6. The composite membrane according to claim 1 , wherein the discriminating layer comprises a polyimide comprising trifluoromethyl groups.
7. The composite membrane according to claim 1 , wherein the discriminating layer comprises a polyimide comprising groups of the Formula (1):
8. A gas separation module comprising a composite membrane according to claim 1 .
9. The composite membrane according to claim 1 wherein GL e has a value of from 200 to 900 nm.
10. The composite membrane according to claim 1 wherein GL i has a value of 10% to 200% of GL e .
11. The composite membrane according to claim 1 wherein GL e has a value of from 400 to 900 nm and GL i has a value of 20% to 90% of GL e .
12. The composite membrane according to claim 11 wherein the gutter layer comprises dialkoxysilane groups and the discriminating layer comprises a polyimide comprising trifluoromethyl groups.
13. The composite membrane according to claim 1 which has a CO 2 gas permeance of 5 to 150×10 −5 m 3 (STP)/m 2 ·s·kPa.
14. The composite membrane according to claim 1 being a composite gas separation membrane.
15. The composite membrane according to claim 11 being a composite gas separation membrane.
16. The composite membrane according to claim 12 being a composite gas separation membrane.
17. A gas separation module comprising a composite membrane according to claim 12 .
18. A gas separation module comprising a composite gas membrane according to claim 14 .
19. A gas separation module comprising a composite gas membrane according to claim 15 .
20. A gas separation module comprising a composite gas membrane according to claim 16 .