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Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: scientizscht on 30/11/2019 16:52:44

Title: Can pore wetness be achieved while maintaining fluidic connection?
Post by: scientizscht on 30/11/2019 16:52:44

Hello!

When a liquid gets absorbed on a porous material, I assume a layer of liquid spreads and covers the pores surface. Is there a gap in the pores on top of the liquid layer that covers the pores surface?

Also, in such phenomenon, is the fluidic connection maintained across the whole absorbed liquid or there is separation in different areas?

Thanks!

Title: Re: Can pore wetness be achieved while maintaining fluidic connection?
Post by: Kasey00 on 14/12/2019 20:42:53

Quote from: scientizscht on 30/11/2019 16:52:44

is the fluidic connection maintained across the whole absorbed liquid or there is separation in different areas?

Separating intimate mixtures of immiscible liquids into continuous streams of their constituent liquids is a critical process in flow-based chemistry.1 Key applications of liquid–liquid separation include: (i) multistep chemistry where it may be necessary to switch repeatedly between segmented flow and single-phase flow to carry out different steps of a reaction; (ii) inline analysis,4 where moving from a segmented flow to a single-phase flow can simplify detection; and (iii) purification where it is necessary to separate a target molecule (in one solvent) from impurities (in the other) following liquid–liquid extraction.

Title: Re: Can pore wetness be achieved while maintaining fluidic connection?
Post by: evan_au on 15/12/2019 01:51:39

Quote from: OP

Is there a gap in the pores on top of the liquid layer

It depends on the nature of the liquid, the film, and the size and composition of the pores.

If the pores are literally holes in the same material as the film, then the liquid will treat the pores similarly to the film.
- If the liquid wets the film (hinted by your "absorbed on"), then it will be absorbed into the pores (if they are big enough for the molecules to get through), and probably absorbed onto the other side of the film. This effect is used for reverse osmosis (assisted by high pressures).
- If the liquid does not wet the film, then it probably won't get absorbed by the pores, either. This effect is used for some wet-weather gear, that keeps rain off, but still allows water vapour to pass through the pores.

Biological films are much more complex, as the pores are made of different composition than the cell wall
- The pores can let through specific molecules
- These molecules may or may not be attracted to the general cell wall
- And sometimes, only let these molecules through at specific times (eg when nerve fibers fire, sodium and potassium ions flow across the cell wall).