The present specification provides a composition comprising a material of Chemical Formula 1: ##STR00001##
having a molecular weight of 500,000 to 700,000 where R1 and R2 are the same as or different from each other, and each independently is hydrogen, deuterium, or an alkyl group, and n is from 10,000 to 20,000, for forming a reverse osmosis membrane protective layer, a method for preparing a reverse osmosis membrane using the same, a reverse osmosis membrane and a water-treatment module.

The present invention relates to ultrathin polymer nanofilm and its composite membrane, its method of preparation. Composite membranes are produced via interfacial polymerization of diamine (or polyamine) monomer (or polymer) and trimesoyl chloride. After IP, post-treatment of washing nascent nanofilm with sufficient volume of solvent and drying at room temperature for 10-30 s followed by annealing at 70-100° C. for 1-10 min is developed. This washing step removes remaining TMC in organic phase and stops further growth of polyamide nanofilm. Ultrathin nanofilm composite membrane gives high water permeance (up to 61.3 Lm.sup.−2h.sup.−1bar.sup.−1) with high rejection of Na.sub.2SO.sub.4 (up to 99.3%) by maintaining relatively low rejection of MgCl.sub.2 (up to 27.7%) and NaCl (up to 11.9%) tested under 5 bar pressure at 25 (±1) ° C. with 2 g/L feed solution.

The purpose of the present invention is to provide a composite semipermeable membrane whose water permeability is hard to decline even when exposed to high temperature environment for a long period of time, a spiral wound separation membrane element using the composite semipermeable membrane, and a method for producing the same. Another purpose of the invention is to provide a method for evaluating water permeation performance of a composite semipermeable membrane, which method evaluates whether the water permeability of a composite semipermeable membrane is likely to decline due to heat, by a simple evaluation method. The composite semipermeable membrane having a skin layer that includes a polyamide resin, the skin layer being placed on a porous support and having an elastic modulus of 100 MPa or more, calculated by AFM force curve measurement in water.

The present invention relates to a composite semipermeable membrane including: a support membrane including a base and a porous support layer; and a separation functional layer disposed on the porous support layer and including a crosslinked aromatic polyamide, in which the separation functional layer contains sulfo groups in an amount of 7.0×10.sup.−5 to 5.0×10.sup.−2 g/m.sup.2 and includes a structure represented by the formula 1.

A porous membrane obtainable by a process comprising curing a composition comprising: (i) cross-linking agent(s) comprising at least one ligand group; (ii) inert solvent(s); (iii) polymerization initiator(s); and (vi) optionally monomer(s) other than component (i) which are reactive with component (i); wherein the composition satisfies the following equation: Z=wt(i)/(wt(i)+wt(iii)+wt(iv)) wherein: Z has a value of at least 0.6; wt(i) is the number of grammes of component (i) present in the composition; wt(iii) is the number of grammes of component (iii) present in the composition; and wt(iv) is the number of grammes of component (iv) present in the composition.

The present invention relates to an ion-selective composite membrane having a thickness of between 4 μm and 100 μm, comprising at least one inner layer disposed between two outer layers, wherein: —the outer layers are each formed of a first material comprising a network of nanofibres and/or crosslinked microfibres and pores with a diameter of between 10 nm and 10 μm, —the inner layer is formed of a second material comprising nanoparticles functionalized at the surface by charged groups and/or groups which become charged in the presence of water and having pores with a diameter of between 1 and 100 nm.

The invention relates to dense synthetic membranes made from polymerised phosphonium-based ionic liquids which were found to be particularly suitable for use in gas separation. The membranes are obtainable by copolymerization via UV-curing of a composition comprising a phosphonium-based ionic liquid monomer, a co-monomer, a cross-linker, a surfactant and a photo-initiator, the remainder of the polymerization mixture consisting of water. The invention also relates to a process of manufacturing said membranes, resulting in solid, dense and mechanically stable membranes, and to the use of the membranes so produced in the separation of gas mixtures, particularly gas mixtures containing carbon dioxide.

The present invention relates to highly selective ultrathin polymer nanofilm; its composite membrane; its method of preparation. Composite membranes are produced via interfacial polymerization with addition of surface active reagents (SLS) to aqueous phase of piperazine amine and reacted with trimesoyl chloride. Fabricated ultrathin polymer nanofilm composite membrane gives high water permeance in range of 47.9-59.6 Lm.sup.−2h.sup.−1bar.sup.−1 with high rejection of Na.sub.2SO.sub.4 (91.77-98.47%); low rejection of MgCl.sub.2 (3.2-10.0%); NaCl (8.9-15.3%); high water permeance in range of 8.1-16.4 Lm.sup.−2h.sup.−1bar.sup.−1 with high rejection of Na.sub.2SO.sub.4 (99.81-99.99%); high rejection of MgCl.sub.2 (96.7-98.4%); NaCl (42.1-56.9%) when tested under 5 bar applied pressure at 25 (±1)° C. with 2 gL.sup.−1 feed. Ideal salt selectivity for NaCl/Na.sub.2SO.sub.4 is in range of 296.3-4310.

A method for preparation of conductive polymer/carbon nanotube (CNT) composite nanofiltration (NF) membrane and the use thereof. This conductive polymer/CNT composite NF membrane is obtained by polymerizing conductive polymer into a CNT membrane and then in-situ cross-linking with glutaraldehyde under acidic condition. The synthetic method for the conductive polymer/CNT composite NF membrane is simple and has no need of expensive equipment. The prepared membrane has controllable membrane structure and possesses superior electrical conductivity and electrochemical stability. The membrane can couple with electrochemistry for electrically assisted filtration. With the electrical assistance, the membrane can achieve improved ion rejection performance while retaining high permeability by enhancement of membrane surface charge density, which alleviates the permeability-selectivity trade-off. Furthermore, the electrically assisted NF membrane filtration can also enhance the removal for small molecular organic pollutants.

New carbon nanomaterials, preferably titanium carbide-derived carbon (CDC) nanoparticles, were embedded into a polyamide film to give CDC/polyamide mixed matrix membranes by the interfacial polymerization reaction of an aliphatic diamine, e.g., piperazine, and an activated aromatic dicarboxylate, e.g., isophthaloyl chloride, supported on a sulfone-containing polymer, e.g., polysulfone (PSF), layer, which is preferably previously prepared by dry/wet phase inversion. The inventive membranes can separate CO.sub.2 (or other gases) from mixtures of CO.sub.2 and further gases, esp. CH.sub.4, based upon the generally selective nanocomposite layer(s) of CDC/polyamide.