Abstract:
A self-supported ion exchange membrane is described. The membrane includes: a polymerized and crosslinked monomer, where the monomer includes: a least one ionic group, a polymerized group, and a silicate group; and a polymer chemically bonded to crosslinked monomer through the silicate group.
Abstract:
A membrane stack may be used, for example, in an electrodialysis or other electrically driven membrane separation device. The stack has a plurality of modules, each containing a number of membranes and spacers bundled together. A module can be removed from the stack, for example for diagnosis or repair, preferably by sliding the module out of the stack in a direction parallel to the plane of a membrane or spacer in the stack. A banding mechanism is described for compressing a stack but can be released to allow the stack to be dis-assembled. Preferably, the banding mechanism is also capable of lifting at least an upper end plate or electrode from the stack. Ports communicate with parts of a stack and may be used to perform diagnostic tests. Preferably there stack has at least two modules as described above and each of the two modules has at least one port.
Abstract:
The present disclosure provides a method of producing a cation exchange polymer, the method includes polymerizing an anionic monomer in the presence of a polymerizable crosslinker having a cationic functional group. A sufficient amount of anionic monomer is used to provide both the anionic charges necessary for cation exchange, and the anionic charges necessary to pair with the cationic functional groups in the crosslinker.
Abstract:
This specification describes an ion exchange membrane and a method of making it. The membrane may be used, for example, in an electrodialysis module or electrochemical cell. The membrane comprises an ion exchange polymer and inorganic particles preferably linked to the ion exchange polymer. To make a membrane, inorganic particles are mixed into an ion exchange membrane pre-cursor. A polymerization initiator or catalyst is then added and the resulting mixture is placed in a form and cured. The inorganic particles may comprise, for example, an oxidized form of graphite such as graphite oxide. The ion exchange polymer may comprise an ionic monomer, containing a quaternary ammonium group for anion exchange or a sulfonate group for cation exchange, along with a crosslinking co-monomer containing polymerizable diacrylic functionalities. The membrane is self-supporting and can be made without a supporting fabric.
Abstract:
Disclosed here are semi-permeable cross-linked polyvinyl alcohol (PVA) based membranes that can be used as supports for water purification membranes, and methods for their production. The cross-linked PVA-based membranes are cross-linked with the reaction product of poly-epoxides and -OH groups from the PVA polymers. Methods according to the present disclosure include crosslinking dissolved PVA and dissolved poly-epoxides, casting the cross-linked PVA, and coagulating the cast polymer in a phase immersion precipitation process.
Abstract:
An apparatus for manufacturing membranes is provided, the apparatus comprises a casting section, a processing section and a conveyor system. The casting section prepares a membrane that is conveyed to the processing section. The conveyor system conveys the membrane through the processing section. In the processing section, the membrane is conditioned in tanks to extract residues. The membrane is also subjected to a leak test to detect physical flaws in the membrane. The leak test involves applying a dye to a surface of the membrane. Any dye that leaks through the membrane will provide a high contrast dye mark on an adjacent contrast material, which is indicative of a physical flaw in the membrane. A process for manufacturing and testing membranes is also provided. The process comprises the steps of casting a membrane precursor, curing the membrane precursor to form a membrane and processing the membrane.