Permeable membranes

[OldManMahoney]

Does anyone know of any (widely/commercially available) plastics that exhibit 'fully'-permeable properties? That is the plastic would allow small molecules to move freely in and out (water, carbon dioxide, oxygen, nitrate etc.), but prevent viruses, bacteria etc. from entering? I believe it would need to have mesoporous/nanoporous properties. Can't find anything online! Perhaps what I'm looking for doesn't exist.

 

Basically i'm going through preliminary research for my MSc thesis that i'll be undertaking in summer. I'm looking for a material that could contain a marine microalgae culture whilst allowing water, carbon dioxide, oxygen,nutrients and waste in and out of the container. The container would be positioned in the marine environment (under lab conditions in reality) so it would need to keep out viruses, bacteria and other competing algae.

 

 

 

Any help much appreciated! Also i'm not sure where this post belongs.

[John Cuthber]

Does this help?

http://en.wikipedia.org/wiki/Ultrafiltration

[CharonY]

Sounds like ultrafiltration devices indeed. I generally only use small-sized ones (i.e. for molecular biological stuff), but the same membranes can be also bought in custom sizes. One problem that you will have is clogging, if you intend to do it for any extended amount of time.

[Horza2002]

We have cellophane discs in our lab which we use to grow Streptomyces bacteria on so they don't grow into the agar. This allows all small molecules to pass through them, but not bacteria cells. Any good?

[Adam Green]

Ultrafiltration membranes are a great suggestion but the dead end / direct flow filters can block. You should take a look at lab scale tangential flow filtration (TFF) / crossflow filtration devices as these don't block and can do volumes from 50ml to 5L.