Hybrid membrane for gas separation

1. A method for removing an acid gas from a natural gas feedstock to form a sweetened natural gas, comprising:

flowing the natural gas feedstock over a membrane, wherein the membrane comprises:

a polyether-block-polyamide (PEBA) matrix; and

a cross-linked network comprising functionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticles dispersed through the PEBA matrix;

isolating the acid gas in a permeate from the membrane; and

producing the sweetened natural gas in a retentate from the membrane.

2. The method of claim 1 , comprising forming the membrane by:

forming a polymer solution of polyether-block-polyamide (PEBA);

forming a suspension of functionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticles;

blending a first portion of the polymer solution with the suspension to coat the functionalized POSS nanoparticles with PEBA, forming a primed suspension;

blending the remaining portion of the polymer solution with the primed suspension to form a PEBA/POSS solution;

adding a free radical photoinitiator to the PEBA/POSS solution;

forming a dense film from the PEBA/POSS solution;

drying the dense film to form a dried film comprising functionalized POSS nanoparticles in a PEBA matrix; and

exposing the dried film to ultraviolet (UV) radiation to cross-link the functionalized POSS nanoparticles in the PEBA matrix.

3. The method of claim 2 , comprising forming the suspension from acrylate functionalized POSS nanoparticles.

4. The method of claim 2 , comprising forming the suspension from methacrylate functionalized POSS nanoparticles.

5. The method of claim 2 , comprising forming a gas separation membrane from the membrane.