Questions tagged [adsorption]
The adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface.
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Freundlich Equation's dimensions
So, we have the Freundlich's Isotherm equation as $\frac{x}{m} = kp^{\frac{1}n}$, where the LHS measures the extent of adsorption with the corresponding pressure $p$ in the RHS with the two constants, ...
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What is the difference between BET and Langmuir model for calculating the specific surface area?
Brunauer–Emmett–Teller (BET) surface area is measured by specific surface area of the adsorbent. BET surface area is measured by using non-corrosive gases like $\ce{N2}$, $\ce{CO2}$, $\ce{Ar}$ etc. ...
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Can negative adsorption be considered equal to sorption?
In my book it was written sorption is basically when the substance gets uniformly distributed into the bulk of the solid but at the same time its concentration is higher at the surface then in the ...
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How does activated carbon trap impurities?
I've tried and I've tried to find an answer to this all over the web, but I can't seem to find an in depth explanation.
To the best of my knowledge, activated carbon has a very microporous structure ...
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Selective sorption of toxins by polymethylsiloxane polyhydrate
Polymethylsiloxane polyhydrate (PMSPH) is used as enterosorbent for a couple of decades (nowadays under the trademark "Enterosgel"), intended for binding in the gastrointestinal tract and excretion of ...
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How does water freeze and crystallize on a cold superhydrophobic surface?
Superhydrophobic surfaces are nano-structured to "repel" liquid water and there has been a lot of work done to understand the microscopics of wetting of these nanostructures.
What I currently am ...
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Why increase in enthalpy leads to increase in entropy? [closed]
Given statement: Enthalpy of adsorption is the strength at which molecule (say $\ce{H2}$) is bound to the adsorbent (say some metal center). For a free $\ce{H2}$ molecule, the entropy contribution is ...
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How does physical adsorption of mixed gas occur on solid? (eg I mean how the gas molecules of compete each other for a slot on solid surface)
I am working on sorption phenomenon of gases (including inert gas) on coal seam surface.
For a mixture of 2 gases at a certain pressure, carbon dioxide and methane, for instance, $\ce{CO2}$ is ...
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Surface area: what is the difference?
What are the differences between:
van der waals surface area
solvent accessible surface area
topographical polar surface area
What is the significance of these differences, and what are the ...
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Interaction between a pencil and rubber (eraser)
Is there a interaction between a graphite pencil and and a eraser. For example, if I drew a line on a piece of paper and then erased that, what interaction is occurring?
Is it a Van der Waals ...
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Why does physisorption (physical adsorption) increase with ease of liquefaction?
This is what my textbook says about physisorption
The amount of gas adsorbed by a solid depends on the nature of gas. In general easily liquefiable gases (i.e. with higher critical temperature) ...
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Catalysist activation energy - the Brønsted-Evans-Polanyi relation
I have stumbled upon something called the Brønsted-Evans-Polanyi relation in a study about the design of catalysts (for reactions like those in hydrocracking fuel production.)
The relation shows that ...
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How to convert the D'Arcy and Watt model from activity to concentration in mol/m^3
The D'Arcy and Watt 1970 model in "Analysis of sorption isotherms of non-homogeneous sorbents" for water adsorption is as follows:
$$W = \frac{KK'a}{1+Ka} + ca + \frac{kk'a}{1-ka},$$
where:
$W$ is ...
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What is a typical monolayer formation time for liquid phase adsorbate on a solid surface?
Let's say a solid is submerged in a solution of species with functional groups and a self-assembled monolayer is forming. What are the typical time scales for the formation of a continuous monolayer? (...
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Diffused Layer ion in Electrix Double Layer
When KI is added to AgNO3 soln, so AgNO3 is in excess, collidal particle is AgI:Ag+ with diffused layer of I-, Why is the diffused layer not of NO3- when the anion in excess is NO3-?
If we had KI in ...
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