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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What is the edge of a diamond like?

The chemical structure of a diamond is defined as an endless lattice in which each carbon atom is covalently bonded to four other carbon atoms situated at the four ends of a tetrahedron. But of ...
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1answer
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Does adsorption violate thermodynamics?

My textbook reads as follows: "When a gas is adsorbed, the freedom of movement of its molecules become restricted. This amounts to decrease in the entropy of the gas after adsorption, i.e. Entropy ...
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3answers
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The entropy change during micellization

I was reviewing the thermodynamics of micelle formation from the Wikipedia page and this book. I understood most of the arguments but micellization is supposed to be an entropy driven process with a ...
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9answers
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Would it be possible to destroy gold?

I'm a writer. I have a scenario in which a sizable amount of gold needs to be rendered unusable, preferably completely destroyed. I know an acid like aqua regia is able to dissolve gold, but would ...
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2answers
585 views

How does the silver nucleate on glass in Tollen's reagent mirroring?

I'm trying to figure out how exactly does the silver start to grow during a mirroring with Tollen's reagent. I've made two pictures to illustrate how i see the nucleation/growth process of silver on ...
18
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1answer
578 views

What is the chemistry behind this “petrol from air” technology?

A recent news report in the UK claimed a breakthrough in making a petrol equivalent from carbon dioxide and water: A small British company has produced the first "petrol from air" using a ...
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1answer
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Is adsorption exothermic, and if so, why?

Why is adsorption exothermic? The explanation given in my textbook is: For a process to be spontaneous, the thermodynamic requirement is that, at constant temperature and pressure, $\Delta G &...
9
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1answer
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Treatment of copper (0) with sodium hydroxide

I recently made self-assembled monolayers (SAMs) of alkanethiols on a copper substrate. After scrubbing off the $\ce{Cu2O}$ top layer and rubbing the surface with ether and ethanol, I let my copper ...
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5answers
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Why is Charcoal such an excellent adsorbent?

Charcoal (also activated charcoal) is known to adsorb a huge variety of substances including a variety of paints, dyes and many different kinds of ions. Moreover, the amount of adsorption at normal ...
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1answer
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What forces hold ink on paper?

On regular paper, ink is absorbed, while on photopaper ink stays at the surface and dries for a longer time. What forces act in these two different cases? (see also related questions about pencil ...
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0answers
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How to do pre-treatment on surface and how to clean the glass surface after silanization?

By Silanization, I want to treat surface of some spherical glass beads. Each bead is supposed to be shot in a particle launcher (like a bullet from a gun). I have some detailed question for the ...
4
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1answer
139 views

Soil-solution cations in competition for exchange sites

How could one determine the likelihood of one cation displacing another on a negatively charged exchange site of a clay particle? For example, in a soil solution containing equal parts (by number of ...
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2answers
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How do we determine if some metal will undergo passivation under suitable environment?

The passivity of certain metal fall in order: $\ce{Ti->Al->Cr->Be->Mo->Mg->Ni->Co->Fe->Mn->Zn->Cd->Sn->Pb->Cu}$ Can we predict the order of passivation ...
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1answer
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Why is sand/glass polar? How does lattice structure change polarity?

The molecular geometry of sand is linear. Dipole moment is thus cancelled. But we all know from the meniscus water makes with glass that the dipole-dipole/H-O attraction between sand and water is ...
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0answers
73 views

Estimating Surface Reactions - Liquid, Turbulent Flow

So, I need a method of estimating the influence of a surface (rate constant would do for a start), the idea is to estimate just Reactant + Surface -> Product in a turbulent liquid flow. Now I am ...
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1answer
4k views

How surface passivation works?

Surface passivation is done to deal with "dangling bonds" (for example, $\mathrm{SiO_2}$ layer on top of a $\mathrm{Si}$ layer). But isn't the new surface will have dangling bonds on its own at the ...
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1answer
515 views

Where does the charge on an electrode, responsible for the formation of a double layer once submerged in an electrolyte, come from?

I've started exploring electrical double layers and electrode-tissue interfaces whilst dealing with deep brain stimulation and stimulus artefact. I've heard many times that what causes the double ...
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0answers
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How to choose a colorant for a given substrate?

I know there are volumes of International Colour Index (homepage, wiki, paper), but I can't really extract from there for example what red colorants are compatible with both silk and polyester, etc. ...
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0answers
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What is the best material for my particles?

I'm investigating collision of a particle and a water droplet ($v_\mathrm{drop}=1~\mathrm{m/s}$, $v_\mathrm{particle} \approx 8\ \mathrm{m/s}$, $D_\mathrm{d}=2.8\ \mathrm{mm}$, $D_\mathrm{p}=2.0\ \...
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2answers
58 views

How to reduce surface tension of oil?

I would like to create tiny colored drops slowly falling down in a transparent liquid. The diameter of the droplets must be around 2mm, and their speed must be approximately 0.5 mm / sec. For that, ...