A stack of ion exchange membranes suitable for water purification comprising a plurality of anion exchange membranes (AEMs) and a plurality of cation exchange membranes (CEMs), wherein the colour properties of the AEMs are visibly different to the colour properties of the CEMs. The invention also provides a process for making membrane stacks in which the likelihood of there being two consecutive membranes of like charge is reduced. Furthermore, it is easy to identify whether there are two consecutive membranes of like charge present in the stacks.

Provided are spacers, ion-exchange devices comprising spacers, and methods of preparing spacers for improved fluid distribution and sealing throughout an ion-exchange device. These spacers can include an internal cavity surrounded by a perimeter of the spacer. The perimeter can have a first opening and a second opening within the perimeter, and the first opening and the second opening can be located on opposite sides of the internal cavity. The spacers can also have a first and second plurality of channels located within the perimeter, wherein each channel of the first and second plurality of channels extends from the internal cavity towards the first opening or the second opening.

Provided are spacers, ion-exchange devices comprising spacers, and methods of preparing spacers for improved fluid distribution and sealing throughout an ion-exchange device. These spacers can include an internal cavity surrounded by a perimeter of the spacer. The perimeter can have a first opening and a second opening within the perimeter, and the first opening and the second opening can be located on opposite sides of the internal cavity. The spacers can also have a first and second plurality of channels located within the perimeter, wherein each channel of the first and second plurality of channels extends from the internal cavity towards the first opening or the second opening.

The present disclosure provides an electrodialysis stack that may be used for the treatment of an electrically conductive solution. The stack includes two electrodes (at least one is a recessed electrode), a plurality of ion-transport membranes and stack spacers. The membranes and spacers are arranged between the electrodes to define electrodialysis cell pairs. The stack includes an electrically insulated zone that extends substantially from a distribution manifold past the recessed edge of the electrode and substantially from the recessed electrode to the opposite electrode for a distance that is about 8% to 100% of the total distance between the electrodes. The overlap distance that the electrically insulated zone extends past the recessed edge of the electrode is calculated as: distance in cm=(0.062 cm.sup.−1)*(exp(−60/total cp)*(area in cm.sup.2 of the manifold ducts of the concentrated stream at the recessed edge) +/−10%.

The present disclosure provides an electrodialysis stack that may be used for the treatment of an electrically conductive solution. The stack includes two electrodes (at least one is a recessed electrode), a plurality of ion-transport membranes and stack spacers. The membranes and spacers are arranged between the electrodes to define electrodialysis cell pairs. The stack includes an electrically insulated zone that extends substantially from a distribution manifold past the recessed edge of the electrode and substantially from the recessed electrode to the opposite electrode for a distance that is about 8% to 100% of the total distance between the electrodes. The overlap distance that the electrically insulated zone extends past the recessed edge of the electrode is calculated as: distance in cm=(0.062 cm.sup.−1)*(exp(−60/total cp)*(area in cm.sup.2 of the manifold ducts of the concentrated stream at the recessed edge) +/−10%.

In an aspect, a hydrogen separation unit includes an electrochemical cell stack that includes a separator stack located in between an anode side and a cathode side; a mixed gas conduit for receiving a mixed gas stream to the anode side; an anode removal conduit for removing a helium rich stream from the anode side; and a cathode removal conduit for removing a hydrogen rich stream from the cathode side. The separation stack includes a plurality of electrochemical cells, each of which includes a proton exchange membrane located in between an anode and a cathode. The proton exchange membrane can include a cation. The separation stack can be a cascading separation stack.

A technology that provides various modular biomimetic microfluidic modules emulating varieties of microvasculature in body. These microfluidic-base capillaries and lymphatic Technology modules are constructed as multilayered-microfluidic microchannels of various shapes, and aspect ratios using diverse biocompatible microfluidic polymers. Then, various semipermeable membranes are sandwiched in between these multilayered microfluidic microchannels. These membranes have different chemical, physical characteristics and MWCO values. Consequently, this design will produce much smaller dimension channels similar to human vasculature to achieve biomimetic properties like of human organs and tissues. By interchanging microfluidic-layers or the membranes various diverse modules are designed that act as building blocks for constructing various medical devices, various forms of dialysis devices including albumin and lipid dialysis, water purification, bioreactors, bio-artificial organ support systems. Connecting various modules in diverse combinations, permutations, in parallel and/or in series to ultimately design many unrelated medical devices such as dialysis, bioreactors and organ support devices.

A technology that provides various modular biomimetic microfluidic modules emulating varieties of microvasculature in body. These microfluidic-base capillaries and lymphatic Technology modules are constructed as multilayered-microfluidic microchannels of various shapes, and aspect ratios using diverse biocompatible microfluidic polymers. Then, various semipermeable membranes are sandwiched in between these multilayered microfluidic microchannels. These membranes have different chemical, physical characteristics and MWCO values. Consequently, this design will produce much smaller dimension channels similar to human vasculature to achieve biomimetic properties like of human organs and tissues. By interchanging microfluidic-layers or the membranes various diverse modules are designed that act as building blocks for constructing various medical devices, various forms of dialysis devices including albumin and lipid dialysis, water purification, bioreactors, bio-artificial organ support systems. Connecting various modules in diverse combinations, permutations, in parallel and/or in series to ultimately design many unrelated medical devices such as dialysis, bioreactors and organ support devices.

Ion exchange membranes obtainable by curing a composition comprising: (a) a monomer comprising an aromatic group and at least one polymerisable ethylenically unsaturated group; (b) a photoinitiator which has an absorption maximum at a wavelength longer than 380 nm when measured in one or more of the following solvents at a temperature of 23° C.: water, ethanol and toluene; and (c) at least one co-initiator.

Ion exchange membranes obtainable by curing a composition comprising: (a) a monomer comprising an aromatic group and at least one polymerisable ethylenically unsaturated group; (b) a photoinitiator which has an absorption maximum at a wavelength longer than 380 nm when measured in one or more of the following solvents at a temperature of 23° C.: water, ethanol and toluene; and (c) at least one co-initiator.