Abstract: The present invention relates to a BCDA-based semi-alicyclic homo- or co-polyimide membrane material for gas separation and a preparation method thereof. The polyimide material prepared according to the present invention has high solubility in casting solvents, particularly in polar organic solvents, by interrupting asymmetry in the polyimide chain structure and formation of polyimide complexes compared with aromatic polyimides, and has higher heat resistance than the conventional aromatic polyimides and aliphatic polyimides, so that it is useful for the process of a high-selective permeable composite membrane or a asymmetric hollow fiber membrane used for commercial purposes, suggesting that it can be effectively used as a membrane for gas separation in various fields. In addition, the polyimide material membrane for gas separation of the present invention is useful because it has superior gas separation properties to the conventional commercialized aromatic polyimides or semi-alicyclic polyimides.

Abstract: The present disclosure relates to a composite membrane in which a rubbery polymer is introduced into a gutter layer to suppress the physical aging of the highly permeable composite membrane, and more particularly, to a composite membrane comprising a porous support layer; a gutter layer on the porous support layer; and an active layer on the gutter layer, wherein the gutter layer comprises a blend of poly(l-trimethlsilyl-l-propyne) (PTMSP) and a rubbery polymer and a method for preparing the same. The composite membrane according to the present disclosure has high permeation performance and a remarkable decline in physical aging leading to a decrease in permeability over time and thus has very high industrial applicability.

Abstract: Provided are a methane-selective composite membrane comprising: a UiO-66 type organic-inorganic composite nanoporous material, a MIL-100 type organic-inorganic composite nanoporous material, or a ZIF-8 type organic-inorganic composite nanoporous material to which a methane-selective functional group is introduced for selectively separating methane from a gas mixture containing methane/nitrogen, a use thereof, and a method of preparing the same.

Abstract: Provided are a methane-selective composite membrane comprising: a UiO-66 type organic-inorganic composite nanoporous material, a MIL-100 type organic-inorganic composite nanoporous material, or a ZIF-8 type organic-inorganic composite nanoporous material to which a methane-selective functional group is introduced for selectively separating methane from a gas mixture containing methane/nitrogen, a use thereof, and a method of preparing the same.

Abstract: The present invention relates to a BCDA-based semi-alicyclic homo- or co-polyimide membrane material for gas separation and a preparation method thereof. The polyimide material prepared according to the present invention has high solubility in casting solvents, particularly in polar organic solvents, by interrupting asymmetry in the polyimide chain structure and formation of polyimide complexes compared with aromatic polyimides, and has higher heat resistance than the conventional aromatic polyimides and aliphatic polyimides, so that it is useful for the process of a high-selective permeable composite membrane or a asymmetric hollow fiber membrane used for commercial purposes, suggesting that it can be effectively used as a membrane for gas separation in various fields. In addition, the polyimide material membrane for gas separation of the present invention is useful because it has superior gas separation properties to the conventional commercialized aromatic polyimides or semi-alicyclic polyimides.

Abstract: The present invention provides a anion-exchange composite membrane comprising a copolymer containing a vinylbenzyl trialkylammonium salt repeating unit, a styrene repeating unit and a divinylbenzene derived repeating unit; an olefin additive; a plasticizer; and a polyvinyl halide polymer. The anion-exchange composite membrane comprising a copolymer containing a vinylbenzyl trialkylammonium salt repeating unit, a styrene repeating unit and a divinylbenzene derived repeating unit; an olefin additive; a plasticizer; and polyvinylidene fluoride of the present invention not only displays low electrical resistance, excellent ion exchange capability, excellent ionic conductivity, excellent mechanical properties, excellent chemical properties, and processability, but also is easy to regulate its ion exchange capacity and ionic conductivity. Also, the composite membrane of the invention is easier to produce and cheaper to manufacture than the conventional anion-exchange composite membrane.

Abstract: The present invention provides a cation-exchange composite membrane comprising a copolymer containing a styrene repeating unit introduced with a sulfonation group, a tert-butylstyrene repeating unit and a crosslink repeating unit, an olefin additive, a plasticizer and a polyvinyl halide polymer. The cation-exchange composite membrane comprising a copolymer containing a styrene repeating unit introduced with a sulfonation group, a tert-butylstyrene repeating unit and a crosslink repeating unit, an olefin additive, a plasticizer and a polyvinyl halide polymer of the present invention not only displays low electrical resistance, excellent ion exchange capability, excellent ionic conductivity, excellent mechanical properties, excellent chemical properties, and processability, but also is easy to regulate its ion exchange ability and ionic conductivity. Also, the composite membrane of the invention is easier to produce and cheaper to manufacture than the conventional cation-exchange composite membrane.

Abstract: A separation membrane for olefin separation and olefin separation method using the same are provided.

Abstract: The present invention provides a cation-exchange composite membrane comprising a copolymer containing a styrene repeating unit introduced with a sulfonation group, a tert-butylstyrene repeating unit and a crosslink repeating unit, an olefin additive, a plasticizer and a polyvinyl halide polymer. The cation-exchange composite membrane comprising a copolymer containing a styrene repeating unit introduced with a sulfonation group, a tert-butylstyrene repeating unit and a crosslink repeating unit, an olefin additive, a plasticizer and a polyvinyl halide polymer of the present invention not only displays low electrical resistance, excellent ion exchange capability, excellent ionic conductivity, excellent mechanical properties, excellent chemical properties, and processability, but also is easy to regulate its ion exchange ability and ionic conductivity. Also, the composite membrane of the invention is easier to produce and cheaper to manufacture than the conventional cation-exchange composite membrane.

Abstract: The present invention provides an anion-exchange composite membrane comprising a copolymer containing a vinylbenzyl trialkylammonium salt repeating unit, a styrene repeating unit and a divinylbenzene derived repeating unit; an olefin additive; a plasticizer; and a polyvinyl halide polymer. The anion-exchange composite membrane comprising a copolymer containing a vinylbenzyl trialkylammonium salt repeating unit, a styrene repeating unit and a divinylbenzene derived repeating unit; an olefin additive; a plasticizer; and polyvinylidene fluoride of the present invention not only displays low electrical resistance, excellent ion exchange capability, excellent ionic conductivity, excellent mechanical properties, excellent chemical properties, and processability, but also is easy to regulate its ion exchange capacity and ionic conductivity. Also, the composite membrane of the invention is easier to produce and cheaper to manufacture than the conventional anion-exchange composite membrane.

Abstract: A separation membrane for olefin separation and olefin separation method using the same are provided.

Abstract: The present invention relates to a polyimide-based macromolecular compound which is produced by using DOCDA and one or more diamines selected from the group consisting of MDA, ODA, PDA, TDA, TrMPD, TeMPD and MBCA; and a gas-separation asymmetrical hollow-fiber membrane comprising the same. The polyimide-based macromolecular compound according to the present invention can advantageously be used in the production of a gas-separation hollow-fiber membrane having an asymmetrical structure since the said compound is highly viscous due to a high molecular weight in addition to having outstanding gas permeability and high selectivity while having excellent high heat resistance, chemical resistance, and mechanical properties and being outstandingly soluble in polar organic solvents.

Abstract: A heat dissipating plate for a light emitting diode (LED) includes a metal thin film containing a hydroxyl functional group (—OH). A coating layer is disposed on at least one surface of the metal thin film and includes a carbon nanotube containing a hydrophilic functional group. The coating layer is attached to the metal thin film by bonding the hydroxyl functional group with the hydrophilic functional group in a hydrogen bond.

Abstract: The present invention relates to a polyimide-based macromolecular compound which is produced by using DOCDA and one or more diamines selected from the group consisting of MDA, ODA, PDA, TDA, TrMPD, TeMPD and MBCA; and a gas-separation asymmetrical hollow-fibre membrane comprising the same. The polyimide-based macromolecular compound according to the present invention can advantageously be used in the production of a gas-separation hollow-fibre membrane having an asymmetrical structure since the said compound is highly viscous due to a high molecular weight in addition to having outstanding gas permeability and high selectivity while having excellent high heat resistance, chemical resistance, and mechanical properties and being outstandingly soluble in polar organic solvents.

Abstract: Disclosed herein is a thrust fin for ships which recovers lost energy caused by rotational flow generated behind a propeller, and converts it into thrust. The thrust fin of the present invention has a simple shape, enhances propulsive efficiency of the ship, and can be applied to a real ship thanks to the simple installation thereof, to maximize thrust of the ship. The thrust fin is mounted to a front portion of the rudder of the ship such that left and right sides of the thrust fin, which are integrated with each other into a single body, are asymmetrical. A vertical position, at which the thrust fin is mounted to the rudder, is at an optimum position as determined in consideration of the shape of the rudder and hydrodynamic characteristics.

Abstract: A novel polyvinyl alcohol-based polymer membrane is disclosed. The novel polyvinyl alcohol-based polymer membrane of the present invention comprises two different compounds which are crosslinked by irradiating light such as UV or electronic beams or heat treatment to form a covalent bond between double bonds thereby providing improved properties such as chemical resistance and durability. This invention also relates to a process its preparation.

Abstract: The present invention relates to a method for preparing hexafluoropropylene oxide with high yield, and particularly to a method for preparing hexafluoropropylene oxide comprising the step of performing a two-phase interfacial reaction between an organic phase containing hexafluoropropylene and an aqueous phase containing a hypochlorite oxidant in the presence of a phase-transfer catalyst and a non-ionic surfactant to improve the degree of emulsification and dispersion of the organic phase and to increase the contact interfacial area, thereby increasing the efficiency and the yield of the reaction.

Abstract: The present invention relates to a method for preparing hexafluoropropylene oxide with high yield, and particularly to a method for preparing hexafluoropropylene oxide comprising the step of performing a two-phase interfacial reaction between an organic phase containing hexafluoropropylene and an aqueous phase containing a hypochlorite oxidant in the presence of a phase-transfer catalyst and a non-ionic surfactant to improve the degree of emulsification and dispersion of the organic phase and to increase the contact interfacial area, thereby increasing the efficiency and the yield of the reaction.

Abstract: Disclosed herein is a thrust fin (20) for ships which recovers lost energy caused by rotational flow generated behind a propeller (30), and converts it into thrust. The thrust fin (20) of the present invention has a simple shape, enhances propulsive efficiency of the ship, and can be applied to a real ship thanks to the simple installation thereof, to maximize thrust of the ship. The thrust fin (20) is mounted to a front portion of the rudder (10) of the ship such that left and right sides of the thrust fin, which are integrated with each other into a single body, are asymmetrical. A vertical position, at which the thrust fin (20) is mounted to the rudder (10), is at an optimum position as determined in consideration of the shape of the rudder and hydrodynamic characteristics.

Abstract: A novel polyvinyl alcohol-based polymer membrane is disclosed. The novel polyvinyl alcohol-based polymer membrane of the present invention comprises two different compounds which are crosslinked by irradiating light such as UV or electronic beams or heat treatment to form a covalent bond between double bonds thereby providing improved properties such as chemical resistance and durability. This invention also relates to a process its preparation.