The present invention relates to an asymmetric structure moisturizing mask pack comprising a polylactide. More specifically, the present invention relates to a porous membrane mask pack prepared from copolymers of polylactide and polyvinyl alcohol, wherein the skin contact surface of the mask pack is hydrophilic and the back surface thereof is hydrophobic.

A method for manufacturing a membrane, which includes at least the following steps of: preparing a mixture that contains at least an aqueous solution of a cationic polymer whose pH is between 5 and 8, the cationic polymer having positively-charged groups in this aqueous solution, and an aqueous solution of an anionic polymer, the anionic polymer having negatively-charged groups in this aqueous solution; stirring the mixture; leaving the mixture to mature to cause the ionic interaction between positively-charged groups of the cationic polymer and negatively-charged groups of the anionic polymer, until obtaining within the mixture a membrane in the form of a hydrogel; adding at least one crosslinking agent so as to crosslink the membrane; drying the crosslinked membrane obtained upon completion of the previous step. This membrane is used for the treatment of liquid or gaseous effluents, as well as an antimicrobial support or for heterogeneous catalysis.

The object of the present invention is to provide a porous membrane by which a useful component can be recovered while suppressing the clogging during filtration of a protein solution and from which only a small amount of an eluate is eluted even when an aqueous solution is filtered. The present invention provides a porous membrane containing a hydrophobic polymer and a water-insoluble hydrophilic polymer, the porous membrane having a dense layer in the downstream portion of filtration in the membrane, having a gradient asymmetric structure in which the average pore diameter of fine pores increases from the downstream portion of filtration toward the upstream portion of filtration, and having a gradient index of the average pore diameter from the dense layer to the coarse layer of 0.5 to 12.0.

A composite material contains a nonwoven layer (i) which contains fibers formed from a first thermoplastic elastomer having meshes with a mesh size in the range from 10 to 100 μm, and a membrane layer (ii) which contains a second thermoplastic elastomer and having a layer thickness of less than 30 μm. The membrane is either pore-free (ii.1) or is porous and has pores with an average pore diameter of less than 2000 nm (ii.2). The membrane (ii) is at least partially in direct contact with the fibers of the nonwoven layer (i) and covers the mesh openings in the nonwoven layer (i) at least partially. The fibers of the first nonwoven layer (i) and the membrane (ii) in the contact area are at least partly joined to one another in an interlocking manner.

A process for preparing a hollow fiber includes the steps of providing a dope solution including polyamide imide (PAI), providing an aqueous bore solution including polyethylene imine (PEI), extruding the dope solution in an cross-sectional annular shape and ejecting the bore solution in the center of the annular shape, allowing the PAI and the PEI to react, thereby forming an internal surface layer including the cross-linked reaction product, and forming a polyamide Thin Film Composite (TFC) layer by interfacial reaction of aqueous di- or triamine compound and organic di- or triacylhalide compound on the internal surface layer including the cross-linked reaction product.

The present disclosure describes compositions and methods for preparing membrane protein nanosheets and two-dimensional crystals. In particular, the methods employ a solvent. A mixture of a polymer and a membrane protein is solubilized in the solvent, applied to a substrate, and subsequently dried to form the nanosheet or two-dimensional crystal. Applicants have surprisingly found that the membrane proteins maintain their structure when exposed to solvents during the short processing time utilized.

A process for preparing a porous film of a fluoropolymer, including the following steps: the provision of an ink including the fluoropolymer and a vehicle including a solvent for the fluoropolymer and a nonsolvent for the fluoropolymer, the solvent for the fluoropolymer and the nonsolvent for the fluoropolymer being mutually miscible; the deposition of the ink on a substrate; the evaporation of the vehicle comprising the solvent and the nonsolvent.

The present invention provides a coated hollow fiber membrane which has an isoporous inner skin and a porous outer support membrane, i.e. an inside-out isoporous composite hollow fiber membrane, and to a method of preparing such membranes. The coated hollow fiber membrane is prepared by a method comprising providing a hollow fiber support membrane having a lumen surrounded by the support membrane, and coating and the inner surface thereof by first passing a polymer solution of at least one amphiphilic block copolymer in a suitable solvent through the lumen of the hollow fiber support membrane and along the inner surface thereof, thereafter pressing a core gas stream through the lumen of the coated hollow fiber mebrane, and thereafter passing a non-solvent (precipitant) through the lumen of the coated hollow fiber membrane. In order to remove the solvent or solvents completely, the membranes are kept in water for 1-2 days and washed prior to use. In order to maintain the porosity of support membrane, membrane pretreatment is advantageous prior to coating which reduces the infiltration of block copolymer solution. The membranes are useful infiltration modules, in particular microfiltration modules, ultrafiltration modules, nano-filtration modules.

The present disclosure provides a liquid membrane conveying apparatus for preparing a porous membrane includes a transmission unit and a carrier unit. The carrier unit conveys a liquid membrane into a gelling solution by the entrainment of the transmission unit. The carrier unit includes a first carrier and a second carrier. The first carrier and the second carrier respectively contact with opposite edges of the liquid membrane along a conveying direction of the liquid membrane. The consistency of the pores on the two surfaces of the porous membrane is improved by using the liquid membrane conveying apparatus.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent and a solvent is provided. The dissolvable polyimide is represented by formula 1: ##STR00001## wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A′ is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1≤X≤0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A wet phase inversion process is performed on the polyimide membrane.