NanoseenX nanomembranes - Page 1
Forum section: electronics / general

author: larsdenmark
author_rank: Regular Contributor
timestamp: September 13, 2023, 08:53:48 am
content: Have anyone of your heard about NanoseenX nanomembranes?https://nanoseen.com/nanoseenxThey offer a nanomembrane that can filter salt away from saltwater using only the force of gravity.I don't think this is even remotely possible.They have a video of how this "works":https://youtu.be/7ny2ynXhQ3Y?si=yZNQneg050QUXoOa&t=56

author: BrianHG
author_rank: Super Contributor
timestamp: September 13, 2023, 10:37:30 am
content: Hmmm, in the video, it says 2-5 minutes for that 1 cup of water from that giant barrel.If my family uses ~10L of water per day, it would take over 3 hours for that thing to make enough water for us.One of those barrels, being replenished non-stop could support 7 low active families. If we exercise or work outdoors needing more water, then we are talking maybe 4-5 families. If I wish to cook and clean with the water as well, let's say it can fulfill 1-2 families.Now, at ~70L per day, how long with that thing, how long until you need a new one. Note that is is way too small and most likely already too expensive for any irrigation / farming.I guess if it lasts a decade, 0 maintenance, 0 worries of no bacteria or poisons/pollutants getting through, having 1 per house, it might be a viable solution. These things will not supply a city, apartment building, farm, or any office building.

author: Haenk
author_rank: Super Contributor
timestamp: September 13, 2023, 12:19:25 pm
content: Haven't loked at the site or video, but filtering is a thing - using reverse osmose filter sheets.Try this one for example (random google hit):https://www.indiamart.com/proddetail/reverse-osmosis-membrane-commercial-4040-19072766062.htmlLooks like the sheet is made by LG.However this requires pressure, just gravity will not work very well. Also: The larger the surface, the more water will pass.

author: larsdenmark
author_rank: Regular Contributor
timestamp: September 13, 2023, 02:06:24 pm
content: I have worked with reverse osmosis in the past. It requires huge pumps and a lot of energy to work. The idea for reverse osmosis membranes is that they have tiny holes that let water molecules through, but not salt molecules. The problem is that those holes are so small to they prevent water from going through unless the pressure on the salt water side is very, very high.If we imagine that gravity for some reason is possible to drive this then for each liter of water there goes through the filter there will be 7 g of salt that will be retained ny the filter. This salt will clog the filter. Also this high salt concentration will lead to osmosis that will drive the water from the "pure" side back into the salty side.I think all of this is a hoax and you can't even get a cup of desalinated water out of this thing no matter how much saltwater you use.

author: helius
author_rank: Super Contributor
timestamp: September 13, 2023, 08:52:24 pm
content: Not to mention that reverse osmosis requires a siphon to "exhaust" the concentrated brine produced on the salt side of the membrane, and requires the water used to be throroughly pre-filtered to eliminate any sediment.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 13, 2023, 11:10:20 pm
content: That looks legit.I'm sure this isn't yet another startup that tries to get EU grants to live off of for a couple years and then disappears.

author: analityk
author_rank: Regular Contributor
timestamp: September 13, 2023, 11:29:29 pm
content: It is.Ions in water solutions are connected with water molecules by van der Vaals bonding. It is relatively small force with comparison to other chemical bonding but it still is serious business. One cation may be connected with many water moleculer or rather it attracts molecule with different charges. When you want to remove ions from water you must be stronger than this forces. There is also more terms to know as ion forces or ion activities potential but reverse osmosis need high pressures becauses this Van Der Vaals forces exist. They exist between any molecules with dipole momentum. Thechnicaly in water you can't find single molecules, even in vapor stage there are some of them connected together, because water molecula act like small magnet.So this guy's in my opinion discover something interesting but anyway thermodynamics laws is bit of biatch and anyone can not to win with them. Purification always cost energy due to entropy change. Always.

author: Haenk
author_rank: Super Contributor
timestamp: September 14, 2023, 01:45:56 pm
content: Quote from: helius on September 13, 2023, 08:52:24 pmI think they will just satiate the filters in this demo. So no "exhaust" is needed, but you need to throw away the filters after a (very?) short time. Plus you will need several filter stages.Interesting, but I don't think this will make it into a market-ready product. It's rather a tech demo, about what the filters can achieve.