.. _sphx_glr_api_gallery_surface_gibbs_adsorption:

Gibbs adsorption equation
---------------------------

Measuring how much solute is adsorbed at a liquid surface from surface
tension alone, via the Gibbs adsorption equation and the Szyszkowski
equation.


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    <div class="sphx-glr-thumbnails">

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    <div class="sphx-glr-thumbcontainer" tooltip="Gibbs showed that the amount of a dilute solute held at a liquid surface, the surface excess \Gamma, follows from how the surface tension changes with concentration: \Gamma = -(1/RT)\,d\gamma/d\ln c. So a surfactant that lowers \gamma must be concentrated at the surface, and no one has to look at the surface itself. This example takes Szyszkowski-type surface-tension data (~chemistrykit.surface.systems.gibbs_adsorption.szyszkowski_surface_tension) for an aqueous fatty-acid-like solute and applies gibbs_surface_excess. It recovers a saturating Langmuir curve for \Gamma and, from the plateau, the area each adsorbed molecule occupies.">

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  .. image:: /api/gallery/surface/gibbs_adsorption/images/thumb/sphx_glr_plot_01_gibbs_adsorption_equation_thumb.png
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  :doc:`/api/gallery/surface/gibbs_adsorption/plot_01_gibbs_adsorption_equation`

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      <div class="sphx-glr-thumbnail-title">The Gibbs adsorption equation: surface excess from surface tension</div>
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    </div>


.. toctree::
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   /api/gallery/surface/gibbs_adsorption/plot_01_gibbs_adsorption_equation