Provided is a semipermeable membrane with high chlorine resistance and high alkali resistance. A cellulose mixed ester represented by a structural formula of General Formula (I), wherein when X is an aromatic acyl group, a degree of substitution is from 2.91 to 3.0; the aromatic acyl group includes a benzoyl group (A) that may include a substituent, and an aromatic acyl group (B) containing a carboxyl group or a salt of a carboxyl group; when the degree of substitution is 3.0, a degree of substitution of the benzoyl group (A) that may include a substituent is from 2.4 to 2.95, and a degree of substitution of the aromatic acyl group (B) containing a carboxyl group or a salt of a carboxyl group is from 0.05 to 0.6; and in General Formula (I), all or part of Xs are aromatic acyl groups; when part of Xs are aromatic acyl groups, the remainder represents a hydrogen atom or an alkyl group; and n represents an integer from 20 to 20000.

A 3-dimensional (3D) nasal pod structure is described having a filter that fits in the nasal cavity to capture particles such as pollen, allergens, pollution particles present in air when breathing through the nose.

A 3-dimensional (3D) nasal pod structure is described having a filter that fits in the nasal cavity to capture particles such as pollen, allergens, pollution particles present in air when breathing through the nose.

The problem to be solved by the present invention is to provide a separation film mainly comprising a cellulose-based resin having high permeability. The present invention pertains to a separation film containing a cellulose ester, wherein the separation film is provided with a bicontinuous structure comprising voids and phases containing the cellulose ester, and the width of the voids is 1 to 200 nm inclusive.

The problem to be solved by the present invention is to provide a separation film mainly comprising a cellulose-based resin having high permeability. The present invention pertains to a separation film containing a cellulose ester, wherein the separation film is provided with a bicontinuous structure comprising voids and phases containing the cellulose ester, and the width of the voids is 1 to 200 nm inclusive.

A problem to be solved by the present invention is to provide a separation membrane having excellent separation performance, having high membrane strength and high permeation performance, and mainly including a cellulose-based resin. The present invention is concerned with a separation membrane including a cellulose ester, having, in the interior thereof, voids each having a specified structure, and having a tensile elasticity of 1,000 to 6,500 MPa.

A problem to be solved by the present invention is to provide a separation membrane having excellent separation performance, having high membrane strength and high permeation performance, and mainly including a cellulose-based resin. The present invention is concerned with a separation membrane including a cellulose ester, having, in the interior thereof, voids each having a specified structure, and having a tensile elasticity of 1,000 to 6,500 MPa.

A problem to be solved by the present invention is to provide a separation membrane having excellent separation performance, having high membrane strength and high permeation performance, and mainly including a cellulose-based resin. The present invention is concerned with a separation membrane including a cellulose ester, having, in the interior thereof, voids each having a specified structure, and having a tensile elasticity of 1,000 to 6,500 MPa.

A problem to be solved by the present invention is to provide a separation membrane having excellent separation performance, having high membrane strength and high permeation performance, and mainly including a cellulose-based resin. The present invention is concerned with a separation membrane including a cellulose ester, having, in the interior thereof, voids each having a specified structure, and having a tensile elasticity of 1,000 to 6,500 MPa.

The present invention addresses the problem of providing: a composite hollow-fiber membrane having high permeability and high membrane strength; and a production method therefor. The present invention pertains to a composite hollow-fiber membrane that at least has a layer (A) and a layer (B), wherein the layer (A) contains a thermoplastic resin, the layer (A) is provided with a co-continuous structure comprising voids and a phase containing the thermoplastic resin, the co-continuous structure has a structural cycle of 1-1000 nm, and the hole area rate H.sub.A of the layer (A) and the hole area rate H.sub.B of the layer (B) fulfill the relation: H.sub.A<H.sub.B.