6 ms·

If you had a thin sheet of silicon filled with 0.2nm holes, wouldn't that be a membrane?

• AnthonBerg 4y ago
  Not if it’s thick and/or rigid, right?
  • brookst 4y ago
    What would be the advantage? Presumably it would have to be very thin, so rigidity seems like it would just mean fragility. Are you seeing it differently?
    • AnthonBerg 4y ago
      Just speculating!
• VygmraMGVl 4y ago
  Yes, that would be a membrane. There a number of membranes with larger pores that are fabricated like above, but out of polycarbonate (track etch membranes). Some people have also experimented with single and double layers of graphene with a few very small pores. Because they are so thin, you don't need as much porosity for high transport rates. You still have fouling issues, though.
• derefr 4y ago
  What you're picturing has a name: https://en.wikipedia.org/wiki/Fritted_glass https://en.wikipedia.org/wiki/Fritted_glass. It's used in a https://en.wikipedia.org/wiki/B%C3%BCchner_funnel https://en.wikipedia.org/wiki/B%C3%BCchner_funnel instead of filter paper, to efficiently separate liquids from solids. Also, if you take some fritted glass and wrap it around a solid core, such that the holes don't go anywhere — i.e. they're just pits that water molecules (but not anything larger) can enter, and then get stuck there by surface tension — then you've get https://en.wikipedia.org/wiki/Molecular_sieve https://en.wikipedia.org/wiki/Molecular_sieve s.
• SideburnsOfDoom 4y ago
  > If you had a thin sheet of silicon filled with 0.2nm holes That's literally individual silicon atoms removed "The nearest neighbour distance is 0.235 nm" https://www.princeton.edu/~maelabs/mae324/glos324/silicon.htm https://www.princeton.edu/~maelabs/mae324/glos324/silicon.ht...