Artificial membrane-fixed liquid filtration structure

The present disclosure relates to a liquid filtration structure with one or more macromolecule membrane structures including membrane proteins selectively permeable to water molecules and fixed within a pore. A liquid filtration structure according to an exemplary embodiment of the present disclosure increases stability and durability of macromolecule membrane structures including membrane proteins selectively permeable to water molecules, and, thus, can be effectively used in a filtration device for purifying water.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority from Korean Patent Application No. 10-2015-0020980, filed on Feb. 11, 2015, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to a liquid filtration structure with one or more macromolecule membrane structures including membrane proteins selectively permeable to water molecules and fixed within a pore.

BACKGROUND

With the development of industry, there has been a rapid growth of interest in a liquid filtration structure for removing pollutants from fluids. In particular, due to the increase in environmental pollution and population, the lack of drinking water is a pending problem for the whole mankind.

A reverse osmosis membrane, which is a representative conventional separation membrane with high selectivity, provides selectivity to water by allowing only water molecules to pass through a free volume, as a permeation channel, present between polymer chains formed of a polymer constituting an active layer and blocking other molecules or ions. Herein, the free volume as a permeation channel does not have a structure aligned in a direction or a through-type structure, but has a severely tangled or winding structure. Therefore, even a thin active layer has a very complicated and long permeation channel, and, thus, has excellent selectivity but poor permeability.

Meanwhile, a porous separation membrane having a porous structure, such as a nanofilter (NF), and a microfilter (MF) has a through-type porous structure, but it is too large to select water molecules or specific ions. Therefore, the porous separation membrane has excellent permeability but poor selectivity.

Further, a water filtration system in which a recombinant aquaporin is located in a vesicle membrane has poor durability due to instability of a lipid membrane structure.

Accordingly, there has been a demand for the development of a new liquid filtration structure which reduces instability of a lipid membrane structure when using a vesicle filtration system and thus has excellent durability.

SUMMARY

The present disclosure has been made in an effort to provide a liquid filtration structure which includes one or more macromolecule membrane structures including membrane proteins increase stability within a pore of a porous support, and, thus, has high filtration efficiency and excellent permeability and durability.

An exemplary embodiment of the present disclosure provides a liquid filtration structure including: a porous support including a plurality of pores of which an inner wall is linked to first linkers; and one or more macromolecule membrane structures including membrane proteins selectively permeable to water molecules, and second linkers. Herein, the first linkers and the second linkers are connected by first connection parts and the macromolecule membrane structures are fixed to the inner wall of the pore of the porous support.

According to the exemplary embodiment, the macromolecule membrane may be any membrane formed of macromolecules which can constitute a membrane, and may be, for example, but not limited to, a lipid monolayer membrane or a lipid bilayer membrane.

According to the exemplary embodiment, the membrane proteins selectively permeable to water molecules may be aquaporin-based proteins.

Aquaporin is a membrane protein responsible for passive transport of water in a cell membrane, and selectively induces water molecules to the inside and outside of cells while blocking movements of ions and other solutes. For example, the aquaporin may include all of aquaporin-based proteins expressed in human bodies, plants, or bacteria, and may include, yeast aquaporin Aqy1, plant aquaporin SoPIP2;1, aquaglyceroporin, i.e., Aqp3, or bacteria aquaporin AqpZ. Further, the aquaporin may be a recombinant protein obtained by artificially expressing the above-described aquaporin-based proteins by the recombinant DNA technology.

Since aquaporin is selected as the membrane proteins, the liquid filtration structure of the present disclosure passes through the proteins included in the porous support, and, thus, selectively and efficiently filters water.

According to the exemplary embodiment, the first linker or the second linkers may include one or more selected from the group consisting of a primary amine reactive cross-linker, a sulfhydryl reactive cross-linker, a carbohydrate reactive cross-linker, a carboxyl reactive cross-linker, and a photoreactive cross-linker.

The primary amine reactive cross-linker may be, for example, but not limited to, imidoesters, N-hydroxysuccinimide ester, or glutaraldehyde, and the sulfhydryl reactive cross-linker may be, for example, but not limited to, maleimide, haloacetyl, or pyridyldisulfide.

Meanwhile, the carbohydrate reactive cross-linker may be, for example, but not limited to, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride or 1,3-dicyclohexyl carbodiimide, and the photoreactive cross-linker may be, for example, but not limited to, aryl azide or diazirine.

Besides, polynucleotide or polydopamine may be used as the first linkers or the second linkers.

The macromolecule membrane structures need the connection parts configured to connect the first linkers and the second linkers in order to be fixed to the inner wall of the pore formed in the porous support. Since the one or more macromolecule membrane structures are connected to the inner wall of the pore through the first linkers and the second linkers, the macromolecule membrane structures can be stably fixed within the pore.

According to the exemplary embodiment, the one or more macromolecule membrane structures may be cross-linked to each other through second connection parts configured to connect the second linkers on the different macromolecule membrane structures. Since the one or more macromolecule membrane structures are connected to each other through the second linkers and the second connection parts, the macromolecule membrane structures can be stably fixed within the pore of the porous support.

According to the exemplary embodiment, the first connection parts or the second connection parts may be any compound capable of connecting the first linkers and/or the second linkers on the different macromolecule membrane structures, and may be preferably hydrocarbon and most preferably polyethylene glycol.

Meanwhile, the macromolecule membrane structures may further include a substance that inhibits fluidity of a membrane constituting the macromolecule membrane. That is, by inhibiting fluidity of the macromolecule membrane to further harden the macromolecule membrane, stability of the macromolecule membrane structures can be increased.

According to the exemplary embodiment, the substance that inhibits fluidity of a membrane may include one or more selected from the group consisting of lipids including cholesterol, sphingolipid, and hydrocarbon having 10 or more carbon atoms, but may is not limited thereto.

According to the exemplary embodiment, the pore may have a diameter of 50 nm to 100 μm, and may have a bottleneck part in a thickness direction of the porous support.

According to the exemplary embodiment, the porous support is not particularly limited as long as it has a porous structure, and may be formed of, for example, a polymer or anodic aluminum oxide.

Meanwhile, the liquid filtration structure according to the present disclosure may include a permeable membrane disposed on an upper end and a lower end of the porous support.

According to the exemplary embodiment, the porous support may have a thickness of 1 μm to 1 mm, preferably 1 μm to 100 μm, more preferably 10 μm to 100 μm, and most preferably 40 μm to 100 μm.

Another exemplary embodiment of the present disclosure provides a liquid filtration structure including: a porous support including a plurality of pores; and one or more macromolecule membrane structures including membrane proteins selectively permeable to water molecules, and second linkers. Herein, the one or more macromolecule membrane structures are cross-linked to each other through second connection parts configured to connect the second linkers on the different macromolecule membrane structures.

In the liquid filtration structure, the one or more macromolecule membrane structures in a pore formed in the porous support are connected to each other through the second linkers and the second connection parts. Thus, this liquid filtration structure is the same as the above-described liquid filtration structure except that the one or more macromolecule membrane structures are fixed to an inner wall through the linkers and the connection parts. Therefore, descriptions of the common parts between these two liquid filtration structures will be omitted to avoid complexity of the present specification.

According to the exemplary embodiments of the present disclosure, a liquid filtration structure increases stability and durability of macromolecule membrane structures including membrane proteins selectively permeable to water molecules, and, thus, can be effectively used in a filtration device for purifying water.

DETAILED DESCRIPTION

The present disclosure suggests a liquid filtration structure configured to stably fix one or more macromolecule membrane structures including membrane proteins selectively permeable to water molecules within a pore formed in a porous support or increase durability.

FIG. 1is a perspective view schematically illustrating that one or more macromolecule membrane structures of a liquid filtration structure is fixed to an inner wall of a pore according to an exemplary embodiment of the present disclosure. In a porous support10, a plurality of pores is formed. A first linker30on an inner wall of the pore is connected to a second linker22present on a macromolecule membrane structure20through a first connection part50. Such connection enables the macromolecule membrane structure20to be stably fixed within the pore of the porous support10.

FIG. 2is a perspective view schematically illustrating that one or more macromolecule membrane structures of a liquid filtration structure is included inside a pore according to an exemplary embodiment of the present disclosure. As illustrated inFIG. 2, a plurality of the macromolecule membrane structures20is present within a pore. Thus, the second linkers22on the different macromolecule membrane structures20can be connected to each other through a second connection part60such that the linking between the macromolecule membrane structures20can be further strengthened and the macromolecule membrane structures20can be stably present within a pore formed in the porous structure10.

On the macromolecule membrane structure20, membrane proteins, such as aquaporin21, selectively permeable water molecules are present. Thus, water can be purified.

Further, a permeable membrane40may be disposed on an upper end and a lower end of the porous support10in order to suppress one or more macromolecule membrane structures20from being leaked to the outside of the pore.

Meanwhile, the macromolecule membrane structures20may further include a substance (for example, sphingolipid or the like) that inhibits fluidity of a membrane constituting a macromolecule membrane. By inhibiting fluidity of the macromolecule membrane to further harden the macromolecule membrane, stability of the macromolecule membrane structures can be increased.