Disequilibrium · disequilibrium:concentration-gradient

Concentration gradient

Different concentrations of a species in two connected regions. Mixing releases free energy that a membrane or electrode can intercept.

symbol ∇cElectrochemistryenergy form chemicalexergy positivealso: Δc, diffusion gradient

Atlas record: 6 claims reference this disequilibrium — 6 established.

Explorerelations · matrix context · routes · sources · cite

6claims28enumerated routes2routes with complete-composition evidence9candidate routes not searched5cited sources

Relations

drives · 5

Concentration gradient—drives→Concentration cell effectestablished

two electrodes of the same kind in solutions of different activity joined by a salt bridge or membrane

E = (RT/zF) · ln(a₁/a₂) · RT/(zF), multiplying the dimensionless logarithm of the activity ratio (25.7 mV/z at 25 °C) [V]

Concentration gradient—drives→Osmosisestablished

Concentration gradient—drives→Diffusionestablished

Concentration gradient—drives→Dufour effectestablished

a composition gradient in a liquid or gas mixture; the heat flux is the Onsager-reciprocal partner of Soret thermodiffusion

Concentration gradient—drives→Chemiosmosisestablished

a proton gradient across a membrane containing ATP synthase

produces · 1

Soret effect—produces→Concentration gradientestablished

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

C.01 Thermoelectric C.02 Thermionic C.03 Thermoacoustic C.04 Pyroelectric C.05 Thermogalvanic C.06 Thermomagnetic C.07 Thermophotovoltaic C.08 Heat engine (thermomechanical)C.09 Caloric (magneto/electro/elasto)C.10 Piezoelectric C.11 Flexoelectric C.12 Triboelectric C.13 Electrostatic (variable capacitance)C.14 Electromagnetic induction C.15 Magnetostrictive C.16 Magnetoelectric C.17 Spin caloritronic C.18 Photovoltaic C.19 Photoelectrochemical C.20 Photothermal C.21 Electrochemical C.22 Osmotic / salinity-gradient C.23 Electrokinetic C.24 Turbomachinery C.25 Magnetohydrodynamic C.26 Radiovoltaic C.27 Nuclear heat C.28 Rectenna C.29 Thermochemical C.30 Biological C.31 Fluctuation / information-driven C.32 Photon momentum C.33 Thermodiffusive C.34 Marangoni C.35 Acoustoelectric C.36 Photodiffusive C.37 Thermo-osmotic C.38 Electrohydrodynamic C.39 Radioluminescent C.40 Thermopolarization

Enumerated routes through this · 28 (showing 24)

Chemiosmotic ATP synthesis2/2 est · demonstrated
Concentration cell3/3 est · demonstrated
Concentration gradient → Dufour effect → Heat flow → Useful heat3/3 est · candidate
Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel4/4 est · extends a recorded pathway
Temperature gradient → Soret effect → Concentration gradient → Concentration cell effect → Ionic current → Electrical work5/5 est · extends a recorded pathway
Temperature gradient → Soret effect → Concentration gradient → Dufour effect → Heat flow → Useful heat5/5 est · same energy form
Chemical potential difference → Combustion → Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel6/6 est · same energy form
Electric potential difference → Peltier effect → Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel6/6 est · extends a recorded pathway
Electric potential difference → Ettingshausen effect → Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel6/6 est · extends a recorded pathway
Incident radiation flux → Photothermal absorption → Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel6/6 est · extends a recorded pathway
Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel6/6 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel6/6 est · extends a recorded pathway
Nuclear binding-energy difference → Nuclear fusion → Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel4/6 est · extends a recorded pathway
Concentration gradient → Osmosis → Osmotic pressure difference → Pressure-retarded osmosis → Hydraulic pressure → Aerodynamic and hydrodynamic lift → Mechanical motion → Mechanical work7/7 est · candidate
Chemical potential difference → Combustion → Temperature gradient → Soret effect → Concentration gradient → Concentration cell effect → Ionic current → Electrical work7/7 est · extends a recorded pathway
Chemical potential difference → Combustion → Temperature gradient → Soret effect → Concentration gradient → Dufour effect → Heat flow → Useful heat7/7 est · candidate
Electric potential difference → Peltier effect → Temperature gradient → Soret effect → Concentration gradient → Concentration cell effect → Ionic current → Electrical work7/7 est · same energy form
Electric potential difference → Peltier effect → Temperature gradient → Soret effect → Concentration gradient → Dufour effect → Heat flow → Useful heat7/7 est · candidate
Electric potential difference → Ettingshausen effect → Temperature gradient → Soret effect → Concentration gradient → Concentration cell effect → Ionic current → Electrical work7/7 est · same energy form
Electric potential difference → Ettingshausen effect → Temperature gradient → Soret effect → Concentration gradient → Dufour effect → Heat flow → Useful heat7/7 est · candidate
Incident radiation flux → Photothermal absorption → Temperature gradient → Soret effect → Concentration gradient → Concentration cell effect → Ionic current → Electrical work7/7 est · extends a recorded pathway
Incident radiation flux → Photothermal absorption → Temperature gradient → Soret effect → Concentration gradient → Dufour effect → Heat flow → Useful heat7/7 est · candidate
Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Soret effect → Concentration gradient → Concentration cell effect → Ionic current → Electrical work7/7 est · extends a recorded pathway
Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Soret effect → Concentration gradient → Dufour effect → Heat flow → Useful heat7/7 est · candidate

Cited sources · 5

[1]
A. J. Bard, L. R. Faulkner. Electrochemical Methods: Fundamentals and Applications (2nd ed.) (2001)
Wiley · book, no DOI · record
[2]
S. R. de Groot, P. Mazur. Non-Equilibrium Thermodynamics (1962)
North-Holland · book, no DOI · record
[3]
R. L. Rowley, F. H. Horne. The Dufour effect. II. Experimental confirmation of the Onsager heat–mass reciprocal relation for a binary liquid mixture (1978)
The Journal of Chemical Physics 68, 325-326 · doi:10.1063/1.435458 · crossref ✓ 2026-09-20 · record
[4]
P. Mitchell. Coupling of phosphorylation to electron and hydrogen transfer by a chemi-osmotic type of mechanism (1961)
Nature 191, 144–148 · doi:10.1038/191144a0 · crossref ✓ 2026-09-19 · record
[5]
D. G. Nicholls, S. J. Ferguson. Bioenergetics (4th ed.) (2013)
Academic Press · doi:10.1016/C2010-0-64902-9 · crossref ✓ 2026-09-19 · record

Cite this entity

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