Nanofiltration or reverse osmosis membrane made of hard carbon film, filtering filter, two-layer-bonded-type filtering filter, and methods for manufacturing same
AssigneeNational Institute for Materials Science
InventorsIzumi ICHINOSE, Yoshihisa FUJII, Sadaki SAMITSU
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Abstract
Provided is a nanofiltration (NF) or reverse osmosis (RO) membrane made of a hard carbon film that has oil resistance and can efficiently separate not only ions in water but also dye molecules present in an organic solvent, a filtering filter, a two-layer-bonded-type filtering filter, and methods for manufacturing the same, using a nanofiltration (NF) or reverse osmosis (RO) membrane (10) made of a hard carbon film characterized by being made of a hard carbon film, having a thickness (t10) of from 5 nm to 300 nm, and having a maximum pore diameter of less than 0.86 nm.
Claims23
1-14. (canceled)
A reverse osmosis (RO) membrane made of a hard carbon film, wherein the RO membrane is made of a hard carbon film, has a thickness of from 5 nm to 300 nm, and has a maximum pore diameter of less than 0.86 nm.
A reverse osmosis (RO) membrane made of a hard carbon film, wherein the RO membrane is made of a hard carbon film, has a thickness of from 5 nm to 300 nm, and allows at least 99% of an azobenzene dye present in an organic solvent not to pass therethrough.
A reverse osmosis (RO) membrane made of a hard carbon film, wherein the RO membrane is made of a hard carbon film, has a thickness of from 5 nm to 300 nm, and allows at least 80% of NaCl in water not to pass therethrough.
A method for manufacturing a reverse osmosis (RO) membrane made of a hard carbon film, the method comprising:
- a step in which an intermediate layer is formed on one side of a support substrate by a spin coating method, a casting method, a dipping method, or a die coating method;
- a step in which the support substrate formed with the intermediate layer is placed in a vacuum chamber, an internal pressure of the vacuum chamber is reduced, a temperature of the support substrate is set to be from −20° C. to 30° C., and then a hard carbon film is formed on one side of the intermediate layer at a film-forming rate of 50 nm/min or less by a plasma CVD method or a sputtering method;
- and
- a step in which the support substrate formed with the hard carbon film is immersed in water or an aqueous acid solution, and the RO membrane made of the hard carbon film is exfoliated from the support substrate.
A method for manufacturing a two-layer-bonded-type filtering filter, comprising:
- a pre-treatment step in which an ultrafiltration membrane is subjected to an organic solvent washing treatment and a vacuum drying treatment after being prepared such that a surface thereof is formed with pores having a diameter of from 1 nm to 50 nm without including a local protrusion of 50 nm or more in a range of 1 μm2 on the surface;
- and
- a step in which the pre-treated ultrafiltration membrane is placed in a vacuum chamber, an internal pressure of the vacuum chamber is reduced, a temperature of the pre-treated ultrafiltration membrane is set to be from −20° C. to 30° C., and then a reverse osmosis (RO) membrane made of a hard carbon film is formed on one side of the pre-treated ultrafiltration membrane at a film-forming rate of 50 nm/min or less by a plasma CVD method or a sputtering method.
Dependencies are inferred from the claim text.