AEM membrane
The anion exchange membrane that separates hydrogen from oxygen
The membrane we use in our own stacks, supplied in small quantities. We are not tied to one manufacturer, so we can point you to the one that fits your conditions. You do not have to meet the manufacturer minimum order.
- Thickness
- 40 – 80 µm
- Standard cut size
- 300 × 300 mm
What this part does and what decides it
Why it matters
The membrane keeps hydrogen and oxygen apart while letting hydroxide ions through. A thinner membrane has lower resistance, so cell voltage drops at the same current, but crossover rises and oxygen on the hydrogen side goes up with it. Thickness is a trade between efficiency and safety, and which way you go is set by operating pressure and target purity.
Background
What actually separates one membrane from another
Three things decide the choice. Fix these three axes first and the manufacturer and product follow from them.
- Thickness
- Thinner means lower resistance; thicker means less crossover
- Construction
- Self-supporting or mechanically reinforced. At the same thickness, mechanical behaviour differs
- Web width
- The largest single piece we can cut. Read it first if you build large cells
Self-supporting versus mechanically reinforced
A self-supporting membrane is one layer of ion exchange polymer. A mechanically reinforced one fills a porous support layer with that same polymer, which is why it is also called a reinforced composite. The ion pathway is the same, but the support holds the shape. At a given thickness that means higher tensile strength and less dimensional change as it wets and dries. The trade is that the support occupies part of the ion pathway, so resistance is slightly higher at the same thickness. Repeated clamping and wet-dry cycling make the membrane expand and contract, and the edges and the area around the ports go first. The support layer restrains that movement.
What arrives
The stock comes on a roll. Tell us the size you need and we cut it from the roll; our standard cut is 300 × 300 mm. Web width therefore sets the largest single piece available, and anything wider is cut in sections. Some products also come in a sheet size fixed by the manufacturer.
The options and the models we handle
What you can choose
Start here and we adjust to your conditions. We can usually source what is not listed.
| Thin self-supporting | Mechanically reinforced | Thick self-supporting | |
|---|---|---|---|
| Thickness | 40 – 50 µm | 50 – 75 µm | 80 µm |
| Where it fits | When you want low resistance | Repeated assembly, long runs | Pressurised operation, high purity |
| Ion exchange polymer alone, with no support. The thinnest option, so resistance is lowest; used for evaluation at ambient or low pressure. The thin self-supporting group below is where these sit. | The same polymer filled into a porous support, which makes it mechanically stable, so it takes repeated clamping and wet-dry cycling better than a self-supporting film does. Also called a reinforced composite. The mechanically reinforced group below is where these sit. | Self-supporting as well, but less crossover for the added thickness. Use it when oxygen on the hydrogen side has to stay low. The thick self-supporting group below is where these sit. | |
| Quote this option→ | Quote this option→ | Quote this option→ |
If you have not settled on one of the three, tell us your operating pressure, your target hydrogen purity and how often the stack is opened. The product follows from those. For a product that is not listed, tell us your conditions and we will check whether we can source it.
Models we supply
The groups are split by physical choice: thickness sets resistance and crossover, and construction sets how much repeated clamping it takes and how long a run it will hold up over. Web width is the widest single piece we can cut, so read that column first if you are building large cells. Prices are quoted against your conditions.
Thin self-supporting — for low resistance
| Model | Thickness | Web width | Supplied as | Origin | Quote this |
|---|---|---|---|---|---|
VersogenPiperION®A40 | 40 µm | 32 cm | Cut from roll | United States | Get a quote→ |
Sino-TechEHYDRO® AEM-01 | 50 µm | 33 cm | Cut from sheet or roll | China | Get a quote→ |
Mechanically reinforced — for repeated assembly and long runs
| Model | Thickness | Web width | Supplied as | Origin | Quote this |
|---|---|---|---|---|---|
VersogenPiperION®A50R | 50 µm | 32 cm | Cut from roll | United States | Get a quote→ |
Thick self-supporting — for pressure and purity
| Model | Thickness | Web width | Supplied as | Origin | Quote this |
|---|---|---|---|---|---|
VersogenPiperION®A80 | 80 µm | 32 cm | Cut from roll | United States | Get a quote→ |
Sino-TechEHYDRO® AEM-01 | 80 µm | 33 cm | Cut from sheet or roll | China | Get a quote→ |
Reading this table
- Cutting
- Cut to your size within the web width; anything wider is cut in sections
- Manufacturers
- EHYDRO® AEM-01 is made by Sino-Tech Hydrogen and PiperION® by Versogen, Inc.; we resell both
- Specification basis
- We re-confirm the current manufacturer specification before placing an order
What to settle before a quotation
Questions we get
Only what has come up more than once in real enquiries.
Which membrane fits
Is a thinner membrane always better?
No. Resistance drops but crossover rises. If you run under pressure or need high purity, the thicker side may be the right call.
When should we use the reinforced one?
When you open and close the stack often, or run it for long periods. Repeated clamping and wet-dry cycling wear the edges and the area around the ports first, and the support layer restrains that movement. If you are only screening for a few days in a single cell, you do not need it.
Do different manufacturers perform very differently?
At the same thickness, the substrate and the reinforcement method change mechanical behaviour. For short screening runs you do not need a reinforcement layer; for repeated assembly or long runs the reinforced side is better. Tell us your conditions and we will work out which product fits.
After it arrives
There is an extra film on the membrane. What is it?
A support substrate. It is a carrier added so a thin membrane is easier to handle, and it comes away when you immerse the membrane in water. What goes into the cell is the same membrane either way.
Send us the checklist
Fill in only what you know. We ask about the rest.
- What it is fore.g. a short stack
- Operating pressure and target puritye.g. 10 barg, 99.999%
- How often the stack is openede.g. two or three times a month
- Thickness band, or the products you want to comparee.g. 40 µm, standard against reinforced
- Number of sheets, cut size and timinge.g. 10 sheets, 100 × 100 mm, next month
Warranty — We verify conformity to the manufacturer specification. Performance under your operating conditions is not covered