Disadvantages of The Model
The Langmuir adsorption model deviates significantly in many cases, primarily because it fails to account for the surface roughness of the adsorbate. Rough inhomogeneous surfaces have multiple site-types available for adsorption, and some parameters vary from site to site, such as the heat of adsorption.
The model also ignores adsorbate/adsorbate interactions. Experimentally, there is clear evidence for adsorbate/adsorbate interactions in heat of adsorption data. There are two kinds of adsorbate/adsorbate interactions: direct interaction and indirect interaction. Direct interactions are between adjacent adsorbed molecules, which could make adsorbing near another adsorbate molecule more or less favorable and greatly affects high-coverage behavior. In indirect interactions, the adsorbate changes the surface around the adsorbed site, which in turn affects the adsorption of other adsorbate molecules nearby.
Read more about this topic: Langmuir Adsorption Model
Famous quotes containing the words disadvantages of and/or model:
“If the factory people outside the colleges live under the discipline of narrow means, the people inside live under almost every other kind of discipline except that of narrow means—from the fruity austerities of learning, through the iron rations of English gentlemanhood, down to the modest disadvantages of occupying cold stone buildings without central heating and having to cross two or three quadrangles to take a bath.”
—Margaret Halsey (b. 1910)
“Socrates, who was a perfect model in all great qualities, ... hit on a body and face so ugly and so incongruous with the beauty of his soul, he who was so madly in love with beauty.”
—Michel de Montaigne (1533–1592)