1. Technical Field
The present invention relates to a composite membrane and a method of manufacturing the same, and more particularly, to a micropore-containing composite membrane, which can be manufactured to a large area by a simple process, and a method of manufacturing the same.
2. Description of the Related Art
Membranes can be classified into porous membranes, dense membranes, and composite membranes, depending upon structures thereof.
Among the membranes, composite membranes include an active layer determining separation efficiency, and a porous support capable of minimizing resistance to permeation materials and maintaining pore characteristics and mechanical strength of the composite membranes. The composite membranes may include an active layer of a low thickness to reduce resistance to the fluid passing therethrough, thereby providing selectivity and excellent permeation performance and significantly contributing to practical applications of the membranes due to a merit of adjustability of selectivity and permeability.
Therefore, studies into manufacturing a novel composite membrane for various applications are being carried out.
In the related art, although a method of manufacturing a phase separation-based nano-porous composite membrane is well-known in the art, since it is difficult for a homopolymer blend in a solution or molten state to prevent a phase-separated domain from being gradually coarsened and becoming larger due to high mobility of soft materials, it is difficult to obtain a porous active layer having a pore size of 10 nm or less.
As other methods of manufacturing a composite membrane, methods of manufacturing a composite membrane are also known in the art. In these methods, a porous active layer having a pore size of 10 nm or less can be obtained through self-assembly of a block copolymer, chemical vapor deposition of carbon nanotubes, or deposition of nanoparticles. However, in these methods, since it is difficult to manufacture a large-size composite membrane or a composite membrane exhibits low dimensional stability, the composite membrane cannot be used at high temperatures or in various solvents.
Therefore, the inventors of the present invention have conceived the present invention by paying attention to research results showing that an active layer including pores having a size of 10 nm or less can be manufactured by a simple process using concentration polarization of anorganic sol of reactive, nano-particulate covalent networks on the surface of a porous support and can be applied to a manufacturing process of a large-area composite membrane.