Quick question - orientation of a hydrophobic / hydrophilic molecule

In summary, the conversation revolved around the movement and orientation of molecules with hydrophobic and hydrophilic properties in water. It was stated that the hydrophobic part of the molecule will move to the surface of the liquid, while the hydrophilic part will not. The question of how the orientation of multiple molecules would look like was raised, with a request for an image or explanation. The reference to micelles was made, which helped clarify the concept. Additionally, a detail about the formation of EZ water at a hydrophilic surface was mentioned, and the question of whether the same formation occurs at a phase surface was posed. It was suggested that the surfactant molecule would be excluded from the surface by layers of EZ water
  • #1
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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  • #4
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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1. What is the difference between a hydrophobic and hydrophilic molecule?

A hydrophobic molecule is one that is repelled by water and typically does not dissolve in water. Hydrophilic molecules, on the other hand, are attracted to water and have the ability to dissolve in it.

2. How does the orientation of a hydrophobic/hydrophilic molecule affect its interactions with water?

The orientation of a hydrophobic/hydrophilic molecule plays a crucial role in its interactions with water. If the molecule is hydrophobic, it will try to avoid contact with water and will tend to cluster together, forming nonpolar interactions. Hydrophilic molecules, on the other hand, will interact with water molecules through hydrogen bonding and other polar interactions.

3. Can a molecule be both hydrophobic and hydrophilic?

Yes, a molecule can have both hydrophobic and hydrophilic regions. Such molecules are referred to as amphipathic. An example of an amphipathic molecule is phospholipids, which have a hydrophobic tail and a hydrophilic head.

4. How can the hydrophobic/hydrophilic nature of a molecule be determined?

The hydrophobic/hydrophilic nature of a molecule can be determined by conducting a solubility test in water. If the molecule dissolves in water, it is hydrophilic, and if it does not, it is hydrophobic. Another method is to calculate the molecule's polarity using its molecular structure and the electronegativity of its constituent atoms.

5. What are the implications of a molecule's hydrophobic/hydrophilic nature in biological systems?

In biological systems, the hydrophobic/hydrophilic nature of a molecule plays a crucial role in various processes such as cell membrane formation, protein folding, and enzyme-substrate interactions. It also affects the transport of molecules across cell membranes and the stability of macromolecules in the presence of water.

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