0xc9941dee…cc7dsent to0x81c094f7…aa23·#25,940,602·view on Etherscan
# Diffusion-potential-driven autoionization of interfacial water into an ionic lattice
## Abstract
At adsorbate-liquid interfaces in polar liquids, autoionization produces charge carriers with asymmetric mobility: the donated ion is mobile while the retained ion is immobilized in the adsorbate. This generates an enormous electric field by the diffusion potential mechanism. In water, this field is strong enough to autoionize the adjacent liquid - converting neutral ice-like hydrogen bridges into stretched OH^-/H3O^+ ion pairs. The result is an ionic water lattice: every other oxygen is OH^-, every other is H3O^+, held together by Coulomb attraction far stronger than neutral hydrogen bonds. The lattice screens the adsorbate's field through ionic stretch polarization, excludes particles, and self-stabilizes through its ionic character. The mechanism is general to polar liquids with autoionization capability and has been observed in water, methanol, ethanol, isopropanol, acetic acid, and DMSO.
## 1. The diffusion potential at adsorbate-liquid interfaces
At a hydrophilic surface, water adsorbs into an ordered film, a few layers thick (3-4). Autoionization between this adsorbate and the adjacent liquid releases H^+ into the liquid and retains OH^- at the surface. Only one carrier is mobile - the strongest case of the mobility asymmetry that produces a diffusion potential. The same physical principle underlies the membrane potential in cell biology (Bernstein, 1902) and the semiconductor junction (Shockley, 1949).
The loss of bridging hydrogens allows adjacent adsorbate layers to shift and collapse together - the layers slide so that O from one layer meets H from the next, forming new bonds as they compress. The resulting structure is the most stable phase for the deprotonated network: a thin (~1 nm) adsorbate of composition (H3O2^-)_n, with honeycomb layers shifted by half an oxygen. This corresponds to what Gerald Pollack has termed the "fourth phase" of water.
From published data (Chai et al., 2009): 12 nmol H^+ released from a 4 cm^2 membrane corresponds to ~50% ionization in a ~1 nm adsorbate (Nygren, 2026). The resulting surface charge density is ~2.9 C/m^2, producing an unscreened field on the order of 100 MV across the exclusion zone.
## 2. The ionic water lattice
The diffusion-potential field extends into the adjacent liquid and organizes it into an ice-like structure (McGeoch & McGeoch, 2008). Within this structure, the field autoionizes the interlayer hydrogen bridges - each neutral O-H***O bridge becomes a stretched OH^-***H3O^+ ion pair. The field pulls H3O^+ toward the adsorbate and OH^- away.
Every oxygen in the lattice participates in a bridge. The alternation is complete: every other oxygen is OH^-, every other is H3O^+. No neutral H2O remains. The result is an ionic crystal of water - every oxygen has a neighbor of opposite charge. The Coulomb attraction between them is far stronger than the neutral hydrogen bonds of ordinary ice. The field initiates the autoionization, but the ionic lattice is self-stabilizing: it persists because every ion is held in place by its oppositely charged neighbors.
The ionic lattice is impermeable to foreign ions. Every position is occupied, the structure is netto neutral, and it is densely packed. An ion approaching the surface encounters a neutral, tight lattice with no vacancies - the same reason NaCl does not dissolve ions from its interior. This impermeability is what maintains the charge separation between adsorbate and bulk.
## 3. Self-organization by positive feedback
The system develops through a positive feedback loop:
1. Autoionization in the adsorbate releases H^+ into the adjacent liquid, generating the diffusion-potential field.
2. The field autoionizes the adjacent liquid, creating OH^-/H3O^+ ion pairs that order into a lattice.
3. The ionic lattice is impermeable - it physically separates the adsorbate OH^- from the bulk H^+, suppressing recombination.
4. Suppressed recombination shifts the adsorbate autoionization equilibrium toward higher ionization, strengthening the field.
5. The stronger field ionizes more liquid, extending the lattice further.
The loop converges when the field at the growth front is too weak to ionize further water. The thickness - ~300 um in water - is the result, not a parameter.
## 4. Screening
The measured potential across the exclusion zone is on the order of millivolts (Zheng et al., 2006). The unscreened field from the adsorbate is on the order of 100 MV. Something cancels nearly all of it.
The ion pairs screen the adsorbate's field through ionic stretch polarization. Each honeycomb layer is stable in itself - an ionic sheet held together by lateral Coulomb attraction. The interlayer bridges are OH^-/H3O^+ pairs, each stretched by the field. The field drives the layers apart as a whole; the interlayer Coulomb attraction resists. Equilibrium is reached when the internal field from the stretched pairs cancels the external field.
A neutral H2O molecule can only rotate its small dipole (~3 D). An OH^-/H3O^+ pair carries full elementary charge across a stretchable distance - far more polarizable. Autoionization converts the entire liquid from a weak dielectric into a strong one. The lattice is ~300,000 layers thick, each contributing to the screening.
## 5. Diffraction evidence
Electron diffraction of the exclusion zone shows hexagonal symmetry consistent with ice (McGeoch & McGeoch, 2008). The measured d-spacing of 3.73 A is compressed ~4% relative to normal ice (3.9 A). The compression arises from Coulomb attraction between neighboring OH^- and H3O^+ ions in the lattice.
The diffraction was performed on flash-frozen samples. If the live structure is more compressed (stronger ionic character at room temperature), partial recombination during freezing would expand the lattice toward ice values. The measured 3.73 A may represent an intermediate between the live ionic lattice and fully recombined ice (3.9 A).
## 6. Spectroscopic and physical properties
The exclusion zone appears liquid-like spectroscopically (Zheng et al., 2006) - its O-H stretch frequencies fall between those of ice and bulk water. This is consistent with an ionic lattice: the O-H bonds in OH^- and H3O^+ have different stretch frequencies than neutral H2O, shifting the spectrum without being liquid.
The higher viscosity of the exclusion zone reflects structural ordering - ions locked in a lattice resist flow - not increased density.
## 7. H^+ release
As the field extends into the liquid and creates ion pairs, H^+ released by the adsorbate diffuses outward through the not-yet-organized water. The exclusion zone forms behind it - the growth front is where new ion pairs are being created, and H^+ that was released earlier is already beyond that front. Once established, the ionic lattice isolates the adsorbate from the bulk.
This accounts quantitatively for the H^+ release measured from exclusion zones (Chai et al., 2009; Nygren, 2026).
## 8. Pressure dependence
The model predicts that the exclusion zone should grow with applied pressure. Pressure compresses the adsorbate -> tighter packing -> more H^+ released -> stronger diffusion-potential field -> more autoionization in the adjacent liquid -> thicker exclusion zone. This has been observed experimentally (Ypma & Pollack, 2015).
## 9. Other polar liquids
The mechanism is not water-specific. Any polar liquid that autoprotolizes can feed an adsorbate-side lyate ion, send the lyonium into the bulk, and grow an ionic lattice of the solvent's own ions:
2 ROH <=> ROH2^+ + RO^-
Particle-excluding regions have been observed in methanol, ethanol, isopropanol, acetic acid, and DMSO, with electrical potential confirmed in water and ethanol (Chai & Pollack, 2010).
For water, the limiting factor for adsorbate ionization is its capacity to house hydroxide, not the bulk autoionization tendency. If the same holds for other solvents, it would explain why even DMSO (pK_auto ~33-35) forms an exclusion zone of ~47 um.
## 10. Discussion
The identification of the diffusion potential as the organizing force, and the ionic water lattice as the organizing structure, resolves a longstanding puzzle. The empirical observations - particle exclusion, weak electrical potential, H^+ release, ordered molecular structure, occurrence in multiple polar liquids - had resisted a unified explanation. The diffusion potential framework combined with the ionic lattice accounts for all of them without new physics.
The key insights are: (1) the source of the H^+ is the ~1 nm adsorbate, and the quantity released implies ~50% ionization; (2) the resulting field is strong enough to autoionize the adjacent liquid; (3) the autoionized liquid forms a self-stabilizing ionic lattice - not merely polarized molecules but an ionic crystal of water, held by Coulomb forces far stronger than hydrogen bonds; (4) this lattice screens the field, excludes particles, and is impermeable to ions.
The resolution requires no new physics. Diffusion potentials, autoionization, Coulomb attraction, and ionic lattice formation are all well-established. What is new is their combination at the adsorbate-liquid interface: a field strong enough to autoionize a polar liquid on a macroscopic scale, creating a self-organized, self-screening ionic lattice extending hundreds of micrometers from a nanometer-scale adsorbate.
## References
Bernstein, J. (1902). Untersuchungen zur Thermodynamik der bioelektrischen Strome. *Pflugers Archiv,* 92(10-12), 521-562.
Chai, B., & Pollack, G. H. (2010). Solute-free interfacial zones in polar liquids. *The Journal of Physical Chemistry B,* 114(16), 5371-5375.
Chai, B., Yoo, H., & Pollack, G. H. (2009). Effect of radiant energy on near-surface water. *The Journal of Physical Chemistry B,* 113(42), 13953-13958.
McGeoch, J. E., & McGeoch, M. W. (2008). Entrapment of water by subunit c of ATP synthase. *Journal of the Royal Society Interface,* 5(20), 311-318.
Nygren, J. (2026). Diffusion potential of autoionization at adsorbate-liquid interface in polar liquids. *Phanerography Certification.* BTC/BSV/ETH/ETC/LTC/DOGE/XTZ/EOS. hashkey:2f61914ae079f073dccabeed03bbfd558ecde0ec761f9a49645edb32b174b295 (sha256).
Pollack, G. H. (2013). *The Fourth Phase of Water: Beyond Solid, Liquid, and Vapor.* Ebner & Sons.
Shockley, W. (1949). The theory of p-n junctions in semiconductors and p-n junction transistors. *Bell System Technical Journal,* 28(3), 435-489.
Ypma, R. E., & Pollack, G. H. (2015). Effect of hyperbaric oxygen conditions on the ordering of interfacial water. *Undersea and Hyperbaric Medicine,* 42(3), 257-264.
Zheng, J., Chin, W.-C., Khijniak, E., Khijniak, E., Jr., & Pollack, G. H. (2006). Surfaces and interfacial water: Evidence that hydrophilic surfaces have long-range impact. *Advances in Colloid and Interface Science,* 127(1), 19-27.