Textbooks Need to Be Re-Drawn
As analytical methods get more sophisticated, existing scientific models are constantly reexamined. The latest to come under scrutiny is the way molecules are organized at the surface of a volume of salt water.
Researchers from the University of Cambridge in the UK, and the Max Planck Institute for Polymer Research in Germany, found that electrically charged particles, or ions, aren’t active on the very surface of the solution, as was previously thought – instead, they’re located in a subsurface layer.
The discovery will require textbook models to be re-drawn, a University of Cambridge press release explains.
“Our work demonstrates that the surface of simple electrolyte solutions has a different ion distribution than previously thought and that the ion-enriched subsurface determines how the interface is organized,” says theoretical chemist Yair Litman from the University of Cambridge.
To make their discovery, the team used an upgraded version of a laser radiation technique called vibrational sum-frequency generation (VSFG), which measures molecular vibrations at the smallest scales with impressive accuracy.
Together with models powered by neural networks, this improved technique meant that the researchers were able to see whether ions at the surface were positively charged (cations) or negatively charged (anions).
As well as detecting the subsurface layer of ions, the new study also reveals that these ions can be oriented in both up and down directions – referring to the actual physical arrangement of the molecules – rather than just one direction.
“At the very top there are a few layers of pure water, then an ion-rich layer, then finally the bulk salt solution,” says Litman.
In simple terms the experiment reveals what’s going on at the very borders of most simple liquid electrolyte solutions. The molecular arrangement informs how they will react with what’s around them.
A thorough understanding of these layers and their arrangement can inform all kinds of other models – such as those we have for the surface of the ocean, for example, which are vital for projecting the effects of climate change on the atmosphere.
And as well as enhancing our understanding of the world around us, the researchers suggest that their work could also help in the development of any kind of technology where solids and liquids have to be combined – including batteries.
“These types of interfaces occur everywhere on the planet, so studying them not only helps our fundamental understanding but can also lead to better devices and technologies,” says molecular physicist Mischa Bonn from the Max Planck Institute for Polymer Research.
“We are applying these same methods to study solid/liquid interfaces, which could have potential applications in batteries and energy storage.”
The research has been published in Nature Chemistry.
Source: Science Alert
Please Donate Below To Support Our Ongoing Work To Expose The Lies About Covid 19
PRINCIPIA SCIENTIFIC INTERNATIONAL, legally registered in the UK as a company 
incorporated for charitable purposes. Head Office: 27 Old Gloucester Street, London WC1N 3AX.
Trackback from your site.
James Bernard McGinn
| #
The mischaracterization of H2O in the 1950s by Linus Pauling has left academia confused about water. Pauling failed to recognize that H2O polarity is variable and that the mechanism that activates dormant polarity is the breaking of hydrogen bonds (the forming of hydrogen bonds neutralizes polarity). Since it is inescapable that the surface of H2O has broken bonds (simply due to the geometric limitations of surfaces) and that below the surface the H2O molecules are fully bonded (no broken bonds) the polarity of the H2O molecules on the surface is high while that below the surface is low or even nonexistent. So, the molecules on the surface of liquid water are polar while those below are not. Since those on the surface are polar they attract each other, excluding the ions and cations.
Science is simple when you get the underlying assumptions correct.
James McGinn / Genius
Reply
Herb Rose
| #
Hi James,
According to your reasoning any surface within the water would prevent neutralization of the hydrogen bonds creating polarity. It is this polarity that is excluding ions from the surface but when salt is submerged in water its is the polarity that is dissolving the salt creating ions. How can the polarity be excluding/repelling ions in one case and being attracted to and creating them in the other?
Herb
Reply
Jerry Krause
| #
Hi James,
I just wrote about the need of accurate definition in physical science and you just used words (terms that need to be accurately defined so readers, and I, can accurately know what you have just stated.
Have a good day
Reply
James McGinn
| #
Herb:
According to your reasoning any surface within the water
JMcG:
Within? I’m referring to the surface of liquid water. A surface “within” wouldn’t be a surface, would it?
Herb:
would prevent neutralization of the hydrogen bonds creating polarity.
JMcG:
Hydrogen bonds don’t create polarity and, in fact, they annihilate it. I’ve never stated anything otherwise, so I don’t know where you are getting this? Also, hydrogen bonds can’t be turned on or off. They are not a force, they just refer to the positional relationship of two H2O molecules relative to one another.
Herb:
It is this polarity that is excluding ions from the surface
JMcG:
Yes, the relatively high polarity of the H2O molecules on the surface causes them to be attracted to each other, thereby excluding ions.
Herb:
but when salt is submerged in water its is the polarity that is dissolving the salt creating ions.
JMcG: I agree. The salt crystals create a surface within the water. This causes an increase of the polarity of the H2O molecules on this surface and, as you suggest, this is instrumental in the creation of ions.
Herb:
How can the polarity be excluding/repelling ions in one case and being attracted to and creating them in the other?
JMcG:
Once the crystals are destroyed (disassembled) they no longer cause a surface within the H2O. Without a surface the polarity of the H2O molecules drops to zero (or, actually, near zero). Having low polarity there is less attraction of the H2O molecules to one another. And since there is low attraction they don’t exclude ions.
Hydrogen bonds don’t create polarity. Polarity is a result of the difference in electronegativity between the oxygen atom and the hydrogen atoms. This difference causes four electrical gradients, two positive and two negative on each H2O molecule. These electrical gradients are what causes the attraction of H2O molecule to each other that results in hydrogen bonds (up to four, one each with up to four other H2O molecules). However, when these bonds form the electrical gradients oppose and contradict each other, dissolving each other’s polarity.
James McGinn / CEO of Solving Tornadoes
Reply
Herb Rose
| #
Hi James,
Where I have a problem is that a submerged surface would prevent the geometrical neutralization of the hydrogen bonds, the same as it does on the surface. This would mean that the water molecules in contact with a container would have a similar polarity as the surface polarity. I understand that there is a difference between interfacial tension and surface tension but if that polarity is expelling ions from the surface layer why is it attracted to these same ions when they are a part of a salt crystal.
What I stated was “preventing hydrogen bonding creating polarity”. You say “Hydrogen bonding don’t create polarity and, in fact, they annihilate it.” I think we are saying the same thing but you are interpreting my statement as: preventing hydrogen bonds “from” creating polarity.
Herb
Reply
James McGinn
| #
Herb:
Where I have a problem is that a submerged surface would prevent the geometrical neutralization of the hydrogen bonds,
JMcG:
Anytime we have forced flatness (or relative flatness) the molecules on this flatness can only form 3 hydrogen bonds. Therefore only 75% (3 x -25%) of the polarity is neutralized, leaving molecules on a surface with 25% polarity. How is this hard to understand? Please explain, because I really don’t get it.
Herb:
the same as it does on the surface. This would mean that the water molecules in contact with a container would have a similar polarity as the surface polarity.
JMcG:
Obviously. Do you have a problem with this? If so, explain why.
Herb:
I understand that there is a difference between interfacial tension and surface tension
JMcG:
I think you don’t understand that interfacial is still just a surface. So, there is no difference between an interfacial surface and a surface as regards hydrogen bonding . I was referring to the difference between a surface and no surface.
Herb:
but if that polarity is expelling ions from the surface layer
JMcG:
Obviously it is because the attraction to other polar molecule (on the surface) is greater than the attraction to the ions, thus excluding the ions from the surface. Is this not obvious to you?
Herb:
why is it attracted to these same ions when they are a part of a salt crystal.
JMcG:
Keeping in mind that the “ions” are not ions when they are part of the crystal, the answer to your question is that this was due to the properties of the now dissolved crystal? (Also, I used the word excluded, not expelled. The word expel suggest they are being pushed out into the atmosphere.)
Herb:
What I stated was “preventing hydrogen bonding creating polarity”. You say “Hydrogen bonding don’t create polarity and, in fact, they annihilate it.” I think we are saying the same thing but you are interpreting my statement as: preventing hydrogen bonds “from” creating polarity.
JMcG;
Oh. Yes. So, you are using the phrase as an adjective and I thought you intended it as a verb.
James McGinn / CEO of Solving Tornadoes
Reply
Herb Rose
| #
hi james,
Crystals are formed because an electron from one atom is bound to another atom giving that atom a negative charge while the other atom has a positive charge. This is what makes an ionic bond as opposed to a covalent bond, where electrons are “shared” rather than lost. It is these charges that the water molecules are attracted to and break dissolving the salt, it doesn’t happen with covalent bonds like plastic. You are mistaken when you say ions don’t exist in a crystal and the question remains why is the polarity of the water excluding these ions in the surface layer while being attracted to them on the surface of a salt crystal?
It is difficult to explain all the peculiarities of water (like why does it continue to become less dense (expand) as a solid when it gets colder) because it has so many unique properties.
Herb
Reply
James McGinn
| #
Herb;
Crystals are formed because an electron from one atom is bound to another atom giving that atom a negative charge while the other atom has a positive charge. This is what makes an ionic bond as opposed to a covalent bond, where electrons are “shared” rather than lost.
JMcG:
Yes.
Herb:
It is these charges that the water molecules are attracted to and break dissolving the salt, it doesn’t happen with covalent bonds like plastic.
JMcG:
Yes.
Herb:
You are mistaken when you say ions don’t exist in a crystal
JMcG:
The atoms exist. But they are not ionic until the ionic bond is broken. Right? Or do I have the terminology wrong?
Herb:
and the question remains why is the polarity of the water excluding these ions in the surface layer while being attracted to them on the surface of a salt crystal?
JMcG:
It’s so simple. The answer is pretty obvious if you step your way through the scenario. Okay, I didn’t fully explicate it. But I’m sure you can figure it out. Ask yourself what happens to the ion and the cation after the ionic bond is broken. Isn’t it obvious that hydrogen bonds would form between an H2O molecule and the ion, cation? Lastly, ask yourself this question, why would the H2O molecules along the surface (which are polar [25%]) not exclude the neutralized ions, cations just as they do the neutralized H2O molecules (which have almost zero polarity as a result of comprehensive hydrogen bonding).
Herb:
It is difficult to explain all the peculiarities of water (like why does it continue to become less dense (expand) as a solid when it gets colder) because it has so many unique properties.
JMcG:
I can explain this. I can also explain the exception to the rule that takes place with super chilled water. Actually, once you understand the first (freezing) the explanation for the second (not freezing when temp goes below 0C) jumps out at you. I wouldn’t try to explain it in this forum, but I can give you a hint. The correct answer has to do with the realization that each hydrogen bond is both a connection between 2 H2O molecules, the strength of which is determined by their polarity, and a switch that neutralizes (turns off) 25% of the polarity in both molecules. (And, keep in mind, each H2O molecule can [and will, readily] form up to four hydrogen bonds, one each with up to four neighbors–thus reducing their polarity to zero.)
James McGinn / World’s Number One Expert in H2O.
Reply
Herb Rose
| #
Hi James,
It is the ions (electrons and protons) that exist and form atoms. The atoms are always ionic, which, while neutral (equal positive and negative ions), do have uneven charges. Getting a static electric shock is from electrons leaving the parent atom to attach to another atom that has a more attractive charge. Hydrogen embrittlement of high tensile steel occurs when a proton (from water) is attracted into the crystal structure of the steel and then becomes a hydrogen atom when an electron reforms the atom. Matter is electric with the base state a neutron, which is formed from an electron and proton and has both a negative and positive charge. Energy, which has both a north and south flow of motion, is able to act on these charges (attracted to positive, repel negative) separating them and forming a hydrogen atom where the negative and positive charges are separated. The ions are always there, just difficult to detect.
I am pondering whether the peculiarities of water is due to its similarity to a neon atom with two positive charges attached to its surface rather than being a molecule with covalent bonds. Carbon is in-between metals and nonmetals and should form covalent bonds exclusively but graphite is very good at conducting electricity which makes it bonds appear to be more like metal bonds than covalent. We tend to assign labels based on generalities but there is blending and transitions that make these labels inaccurate. Water seems to defy being classified by labels.
Herb
Reply