Articles including an isoporous membrane disposed on a porous substrate and methods of making the same
The present disclosure provides an article including an isoporous membrane disposed on a porous substrate. The isoporous membrane includes a triblock copolymer or a pentablock copolymer. The isoporous membrane has a thickness and is isoporous throughout its thickness. A method of making an article is also provided, which does not require a solvent exchange process. The method includes depositing a composition on a porous substrate, thereby forming a fdm, and removing at least a portion of the solvent from the film, thereby forming an isoporous membrane having numerous pores. The composition contains a solvent and solids including a triblock copolymer or a pentablock copolymer. The article advantageously can be hydrophilic and provides sharp molecular weight cut-offs and high flux.
1 . An article comprising an isoporous membrane disposed on a porous substrate, the isoporous membrane comprising a triblock copolymer, wherein the isoporous membrane has a thickness and is isoporous throughout the thickness; and
wherein said triblock copolymer comprises an A block comprising a poly (ethylene oxide).
2 . The article of claim 1 , wherein the thickness of the isoporous membrane from a major surface of the porous substrate is 1000 nanometers (nm) or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, or 30 nm or less; and 20 nm or greater, 25 nm or greater, 30 nm or greater, 40 nm or greater, 55 nm or greater, 65 nm or greater, 75 nm or greater, 85 nm or greater, 95 nm or greater, or 105 nm or greater.
3 . The article of claim 1 , wherein the triblock copolymer comprises a B block selected from the group consisting of styrene, p-methylstyrene, alpha-methylstyrene, poly(tert-butylstyrene), and polymethylmethacrylate.
4 . The article of claim 1 , wherein the triblock copolymer comprises a C block comprising a polyacrylate or a polysiloxane.
5 . The article of claim 1 , wherein the isoporous membrane is attached to the porous substrate.
6 . The article of claim 1 , wherein the porous substrate comprises pores having a mean pore diameter at a surface of the porous substrate of 500 nm or less to 1 nm or more.
7 . The article of claim 1 , wherein a standard deviation in pore diameter at a surface of the isoporous membrane is 4 nm or less from a mean pore diameter at the surface of the isoporous membrane when the mean pore diameter at the surface of the isoporous membrane ranges from 5 to 15 nm, the standard deviation in pore diameter at the surface of the isoporous membrane is 6 nm or less from the mean pore diameter at the surface of the isoporous membrane when the mean pore diameter at the surface of the isoporous membrane ranges from greater than 15 to 25 nm, and the standard deviation in pore diameter at the surface of the isoporous membrane is 25% or less of the mean pore diameter at the surface of the isoporous membrane when the mean pore diameter at the surface of the isoporous membrane ranges from greater than 25 to 50 nm.
8 . The article of claim 1 , wherein a portion of the isoporous membrane is integral with a major surface of the porous substrate.
9 . The article of claim 1 , wherein the isoporous membrane is spontaneously water wettable.
10 . The article of claim 1 , wherein the porous substrate comprises a membrane, a nonwoven substrate, or combinations thereof.