Quick question - orientation of a hydrophobic / hydrophilic molecule

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Discussion Overview

The discussion revolves around the orientation and movement of hydrophobic and hydrophilic molecules in water, specifically focusing on the behavior of PFOS molecules at the liquid surface. Participants explore the implications of molecular properties on orientation and layering in aqueous environments.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant questions whether the hydrophilic part of a PFOS molecule will move to the liquid surface, given that the hydrophobic part tends to do so.
  • There is curiosity about the overall orientation of multiple PFOS molecules in water and whether they would form layers.
  • Another participant references micelle formation as a potential relevant concept for understanding molecular orientation.
  • A later contribution introduces the idea of EZ water, suggesting that water at a hydrophilic surface forms a layer that excludes other molecules, which may affect the orientation of surfactants at the surface.
  • The same participant speculates that surfactant molecules in a dilute mixture might be excluded from the surface due to these water molecular layers.

Areas of Agreement / Disagreement

Participants express curiosity and propose various ideas regarding molecular orientation, but there is no consensus on the specific behavior of PFOS molecules or the implications of EZ water at the phase surface.

Contextual Notes

The discussion includes references to specific research and concepts like micelles and EZ water, but does not resolve the assumptions or implications of these ideas on the behavior of PFOS molecules.

rwooduk
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Hi,

I am looking at how molecules with hydrophobic and hydrophillic properties move and orientate themselves in water. If I have say a PFOS molecule...

fig1.png


The hydrophobic part (the perfluoroalkyl group - the carbon chain) will move to the liquid surface but the hydrophillic part (the sulfonate part) will not want to go there. So will it go to the liquid surface at all?

If I have many molecules what will their orientation look like? Will they be layered? It is hard to imagine.

Any ideas as to what the orientation will look like or somewhere that has an image would really help.

Thanks for any help.
 

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Just thought I will add a small detail...according to research conducted at U of Guelph (Canada), water at a hydrophillic surface forms a molecular layer of aligned water molecules and excludes all other molecules and hence Professor Gerald Pollack calls the effective molecular formation as EZ water (exclusion zone). The formation appears to explain surface tension and surface conductivity (free electrons). The question I have is whether the same formation is occurring at a phase surface; it should be, IMHO. Therefore I would expect the surfactant molecule in a dilute mixture, to be excluded from the surface, by one or more water molecular" pseudo-polymer" layers (my term as a former polymer physicist) . It appears that light absorption on the laboratory layout initiated more layers of EZ water to form.
 
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