Questions tagged [surface-chemistry]
Surface chemistry is roughly defined as the study of chemical reactions at interfaces between 2 or more phases.
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Coating a nickel foam with mm poresize with zinc
I'm currently trying to coat a nickel Foam (NF) 1 cm thickness with high loadings and homogenous plating of Zn metal. The main concern right now is that the outer most areas like corners and edges get ...
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Is the surface electron affinity of (tribasic) sodium- or calcium phosphate higher?
Let's imagine we have two polycrystalline samples: $\ce{Ca3(PO4)2}$ and $\ce{Na3PO4}$. A free electron is added to both. Some heat is released.
I wanted to check whether my reasoning about this ...
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What is the highest known temperature where micelles exist?
What are the two liquid phases involved in the formation of roughly spherical micelles at highest possible temperatures? What about a surfactant? At how high temperatures have micelles been observed ...
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Fundamental reasons for using vapors for ALD rather than solutions
Atomic layer deposition (ALD) has been developed for many materials, as can be seen from this overview: https://atomiclimits.com/alddatabase/
However, a search for liquid phase ALD gives less results.
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Which alloy forms the thinnest sulfide surface passivation layer?
Metal sulfides seem to often form thick layers on alloy surfaces exposed to molten $\ce{S}$. Are there alloy surfaces capable of passivation with $\ce{S}$ before the layer thickness reaches $\pu{1 nm}$...
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DIY method for regenerating activated carbon in air filters
I am interested in regenerating activated carbon used in general house-hold air filters. I am looking for a sufficiently efficient and easy method to do this in home setting. A little tinkering in a ...
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Surface Tension at Critical Temperature and at Boiling point [closed]
I recently did an experiment on finding the surface tension of a liquid at different temperatures, When I was going through my lab manual, I found the following statement:
As temperature decreases, ...
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Metallic nanostructures exhibiting charge separation
Mostly ions consist of a few atoms. It is easy to see, why the solids they form must have simple stoichiometries. It is true even for polymeric ions, such as some complicated organic molecular ions as ...
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AC voltage drift
I am applying AC current to a capacitive electrode and recording the change in voltage over time. I have observed a voltage drift that does not follow any consistent pattern. Sometimes, the drift is ...
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Does Adsorption Depend On Shape Of The Adsorbent?
I was reading about the Freundlich adsorption isotherm and when I read the equation I was quite confused. It states that
$$x/m=k(p)^{1/n}$$
So basically x is mass of the adsorbate adsorbed, m is mass ...
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Reaction Rate for Surface Reactions [closed]
Assume reactions S1 to S4 in the image. How can I can determine the reaction rate in mol/m2.s with the given Arrhenius parameters?
Cs' and Cs-H are site species on the surface.
Cs' is just an ...
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Does someone know a unique testable questions surrounding 1 of the 5 variables that affect the rate of a chemical reaction? [closed]
I am a year 11 student studying high school chemistry and we are currently studying catalysts.
I am working on an assessment and need to come up with a unique but testable hypothesis surrounding one ...
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If a crystal has alternating layers of different atoms, will it display different properties depending on which layer is exposed?
Many metal diboride compounds like $\ce{MgB2}$, $\ce{TiB2}$, and $\ce{ReB2}$ have laminated crystal structures with alternating sheets of metal atoms and boron atoms. If we polish the surface to ...
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Is gallium slippery at room temperature in an inert atmosphere?
Ice is slippery when it isn't too far below it's melting point because the surface molecules are less loosely bound than the bulk and form a thin liquid layer.
Pressure melting is a much smaller ...
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Why is the decomposition of gas on a metal surface at high pressure considered a 0 order reaction?
My textbook says that when ammonia decomposes on a platinum surface at high pressure, the reaction is 0-order. This is because at high pressures, the metal surface gets saturated with ammonia ...
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How to determine the surface reaction rate and equilibrium constant for a reaction between a solid site species and gas species
Consider the following reaction mechanism 1:
S1: $\ce{C-H (s) + H (g) <=> C^\star (s) + H2 (g)}$
S2: $\ce{C^\star (s) + H (g) => C-H (s)}$
S3: $\ce{C^\star (s) + C2H2 (g) => C-H (s) + H(g) ...
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Which reaction occurs in calcium vanadate when it comes in contact with water?
I am a physics student currently studying the electrical properties of $\ce{CaVO3}$ and I have noticed that the surface of my thin film samples, which were originally smooth and transparent, now have ...
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Why is n=1 at a low pressure in the Freundlich Isotherm Equation?
On the topic of adsorption of a gas over a solid, the Freundlich isotherm explains this behaviour in an approximate manner via the following equation
$$ \frac{x}{m} = kP^{1/n} \tag{1} $$
where $x$ is ...
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How do I make a 6-mercapto-1-hexanol (MCH) aqueous working dilution?
I am using 6-mercapto-1-hexanol (MCH) as part of the immobilization procedure for forming a self-assembled DNA monolayer on a gold surface (see the first figure of this paper for a good visual ...
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Methods for immobilization of DNA on gold surfaces?
I've been looking for methods for immobilizing 5'-Thiol modified dsDNA on gold slides. Most of what I've come across suggests using DTT followed by a desalting step or using TCEP. However, I haven't ...
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Why surface tension acts tangentially if there is a net inward force? [closed]
I understand that surface tension is caused by an imbalance of forces for molecules on the surface in comparison to those that lie within. As a result, this creates a net inward force that seeks to ...
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Do "pseudo Van der Waals" gases exist?
In college, when deriving the Langmuir isotherm for gas-solid adsorption, the professor proposed a modified version of the Van der Waals state equation, what he called the "pseudo Van der Waals ...
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What does "acidic" mean in an article on hydrogen boride nanosheets?
From Rojas et al. [1] (emphasis mine):
On the other hand, we found that proton exchange with HB occurs in water with the estimated $\mathrm{p}K_\mathrm{a}$ of $3.5\pm 0.2,$ even after reactive sites ...
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Why all commercial SPR instruments use angular interrogation?
Surface plasmonic resonance biosensor devices are used to measure analyte concentration, kinetics, affinity, and specificity without any need for labels. This technique involves the bonding of the ...
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Can micelles form in a polar-vacuum interface?
As the formation of micelles depends on, among many factors, the difference of polarity/relative permittivity of the solvents involved with the surfactant, I'm wondering if a polar-vacuum system is ...
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Would an effervescent tablet react with itself if ground into a nanopowder?
Effervescent tablets usually are a mixture of a weak acid, base, and binder. When dry there is no reaction. But when placed in water the acid-base neutralization releases CO2 rapidly.
If you ground a (...
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Evaporation Rate of Hydrochloric acid
I'm currently working in a Chemical Plant as an intern, and I was given a task to improve the efficiency of the blower, which is already in place right now, by designing a new blower for the ...
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The cleansing action of soap
My textbook says that:
The formation of micelles takes place only above a particular
temperature called Kraft temperature (Tk ) and above a particular
concentration called critical micelle ...
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Adhesion energy vs free energy of solvation
I am looking to compute the solvation free energy of Pt(111). Experimental data are still rare because the entropic term is hard to measure.
I have found a paper where they use a QM/MM approach to ...
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Stability of Mercaptoundecanoic acid and thiol-PEG stored as solids
I am planning to use Mercaptoundecanoic acid (MUA, 98%) and thiol-PEG (O-[2-(3-Mercaptopropionylamino)ethyl]-O′-methylpolyethylene glycol) for functionalisation of gold nanoparticles.
The SDS ...
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Interaction energy of an hydroxide ion with a Pd surface
I need to estimate the interaction energy of a hydroxide ion with a palladium surface of $-0.6$V in water.
I know that the electric field of a charge $e$ is
$$
E = \frac{1}{4\pi\epsilon}\frac{e}{r^2}
$...
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What is the saturation point of dishwashing soap in water?
I am looking to measure the effect of dishwashing soap on the surface tension of water. To select appropriate values for the concentration of dishwashing soap is to find the saturation point first, ...
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Incompatibility of Helmholtz Double Layer and Redox electrochemistry
In an electric double layer capacitor(EDLC) (or any situation with a Helmholtz double layer) what prevents the ions from being reduced or oxidized like the ions in an electrochemical cell?
If it is ...
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Can Surface Energy Be Negative?
In some sources I read, it is written that surface energy can't be negative. However, this doesn't really make sense since surface energy should be negative if molecules on interphase have lower ...
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Stability of Microemulsions
Unlike emulsions, microemulsions are thermodynamically stable. Its stability is often explained by entropy changes brought about by dispersing liquid in another liquid, however this can't be the whole ...
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How can surface excess be negative?
If we have interphase of two phases $\alpha$ (water) and $\beta$ (air), surface excess is defined as
$$\Gamma_i = \frac{n_{i,\mathrm{tot}} - n_{i,\alpha} - n_{i,\beta}} A = \frac{n_{i,\mathrm{int}}} A,...
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Modified Arrhenius equation in the presence of a heterogeneous catalyst
Suppose we are doing heterogeneous catalysis, for example, between nitrogen and hydrogen to create ammonia in the presence of a solid catalyst, like rhuthenium. It's obvious that the gas molecules don'...
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why Tin/Zinc alloys can be used to solder aluminum and Tin alone does not "wet" the aluminum?
It is impossible to solder aluminum with only tin, tin does not "wet" aluminum surface because of the instantaneous reaction aluminum/oxygen on the surface of the base metal (aluminum). I ...
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How can I prevent and remove oxidation on the surface of liquid Galinstan?
The oxide layer formed on galinstan (or its component of pure gallium) when exposed to air increases wetting and dulls the appearance. Is there a clear liquid material in which a blob of liquid ...
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Why does magnesium hydroxide solution solidify after passage of time?
I have been trying to make a suspension of magnesium hydroxide in water. Around 40% magnesium hydroxide w/w. Initially it is fluid, but as time passes, it solidifies. What is causing this?
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Contact Angle Hysteresis
When solid surface is wetted and dewetted with some liquid, contact angle measured will not be the same. I am not sure what does process of wetting or dewetting have to do with contact angle or why ...
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Owens - Wendt Model for Surface Energy of Solid - Liquid Interface
Owens - Wendt model is used for calculating surface energy on liquid - solid interface and it is given by following equation: $$ \gamma_{sl} = \gamma_s + \gamma_l -2(\sqrt {\gamma_l^d \gamma_s^d} + \...
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LEED - determining surface structures
How can one describe surface structures (before and after adsorption)? I understand the diffraction theory but I have never really tried to determine the structures of samples by myself.
LEED (low ...
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Adsorption on solids - homogeneous/heterogeneous surface definition
How could we define homogeneous and heterogeneous surfaces (rigorously)?
It is among my exam questions (but I could not find any definition in my textbook or on the internet).
I would say the ...
user76255
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Is this the first report that acetonitrile & propionitrile crystals create highly polar nano surfaces? How does one detect or quantify such surfaces?
Phys.org's Titan-in-a-glass experiments hint at mineral makeup of Saturn moon says:
Titan, Saturn's largest moon, is a natural laboratory to study the origins of life. Like Earth, Titan has a dense ...
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Why is there preferential adsorption of a common ion during preparation of colloids by peptization?
There was a similar question asked here on Chem SE, but the answer was not very satisfactory to me, so I am asking a fresh question.
Peptization is the process of creating a colloid from a precipitate ...
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What is the theoretical reason for the dependence of the surface tension on the alcohol concentration in water?
The qualitative sketches I, II and III given
below show the variation of surface tension
with molar concentration of three different
aqueous solutions of$ \ce{ KCl, CH_3 (OH) }$and
$ \ce{CH3(CH2)_{11} ...
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Why does physisorption pass into chemisorption on increasing temperature
I have been told, that on increasing temperature, physisorption passes into chemisorption (with greater Activation Energy, generally). But why does that happen?
Shouldn’t the increment in Temperature ...
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A liquid which climbs out of its pot [closed]
My Russian born wife recently asked me to buy her a skin remedy widely used in Russia. In English this is the oil of a plant called Sea Buckthorn. It is a thin yellow liquid. My wife put some of this ...
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Can suspended solid particulate particles adsorb on surface?
Gaseous and liquid particles adsorb on solid surfaces. Can solid particles suspended in a fluid medium also adsorb on these surfaces in the same manner?
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