Ultrathin, conductive and fouling-resistant zwitterionic polymer films
Disclosed are methods of preparing antifouling coatings on reverse osmosis membranes with initiated vapor deposition or oxidative vapor deposition. The coatings enhance the stability and lifetime of membranes without sacrificing performance characteristics, such as permeability or salt retention.
1. A polymer, comprising a plurality of first repeat units, and a plurality of second repeat units; wherein
each of the first repeat units is independently represented by Formula IIA:
wherein, independently for each occurrence,
R 2 is H, alkyl, halo, nitro, or cyano;
Y is a linker that does not comprise an amide bond, an ester bond, or an ether bond; and
X ⊖ is —SO 3 ⊖ or —COO ⊖ ; and
each of the second repeat units is independently represented by Formula IIB:
wherein, independently for each occurrence,
R 2 is H, alkyl, halo, nitro, or cyano.
2. The polymer of claim 1 , wherein R 2 is H.
3. The polymer of claim 1 , wherein X ⊖ is —SO 3 ⊖ .
4. The polymer of claim 1 , wherein the ratio of first repeat units to second repeat units is about 0.8:0.2.
5. The polymer of claim 1 , wherein the ratio of first repeat units to second repeat units is about 2:1.
6. A composition, wherein the composition comprises a substrate and a coating material, wherein the coating material comprises a polymer of claim 1 .
7. The composition of claim 6 , wherein the substrate comprises a polysulfone, a polyimide, or a polyamide.
8. The composition of claim 6 , wherein the substrate is a membrane.
9. The composition of claim 8 , wherein the substrate is a reverse osmosis membrane.
10. An article, comprising a composition of claim 6 ; wherein the article is incorporated into a water desalination device.
11. A method, comprising
contacting, at a first flow rate, a first sample of water with a composition of claim 6 , thereby producing a second sample of water,
wherein the first sample of water comprises a first concentration or first quantity of a substance; the second sample of water comprises a second concentration or second quantity of the substance; and the second concentration or second quantity is substantially lower than the first concentration or first quantity.
12. A method of coating a surface of a substrate, comprising the steps of:
providing a substrate;
exposing a surface of the substrate to plasma for a first period of time at a first pressure, thereby producing a conditioned surface of the substrate; and
contacting the conditioned surface of the substrate with the polymer of claim 1 , thereby producing a polymer-coated substrate.