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Questions tagged [materials]

Material is a general term for a chemical substance or a mixture of substances with certain, well defined physical properties.

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Cyclic Voltammetry for a Capacitor - Positive Current, Potential is decreasing?

In the boxed red region, why is the potential decreasing when the current is still positive? To my understanding, when the current is still positive (i.e. not changing direction), the capacitor will ...
photon's user avatar
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2 votes
0 answers
53 views

Tensile Strength and Young's modulus of 2D vs 3D Materials

I was wondering as to why graphene has not taken over the world. The obvious answer was that we cannot produce large sheets of it and it is expensive. Anyways, the article did mention something else, ...
Ronith's user avatar
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6 votes
1 answer
366 views

How is indium tin oxide a n-type semiconductor?

I was reading about indium tin oxide (ITO) and that it is considered a n-type semiconductor. However, that doesn’t make sense to me. If just one In(III) is replaced by Sn(IV) then we would have an ...
Mäßige's user avatar
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1 vote
0 answers
64 views

The accurate use of a "Mortar and Pestle" and its grinding patterns

At my internship, I was asked to use a mortar and pestle. I placed a pigment sample in the mortar, and was asked to apply a downward pushing motion in a circular pattern with my pestle. I kept a firm ...
Ronith's user avatar
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1 vote
0 answers
18 views

Alternative material for evaporative cooling systems

I aim to make a better model of the traditional evaporative coolant mats made from vetiver (khus) roots. The principle of this is that it cools the surroundings by using evaporative cooling by water, ...
user146624's user avatar
10 votes
2 answers
949 views

Risks of restoring old books from decaying

I was reading this article on " Why Do Old Books Smell So Good?" and I came across a part of it that seemed to be not elaborated upon. Rapidly degrading and at-risk documents that are ...
Ronith's user avatar
  • 1,273
3 votes
1 answer
549 views

Are there any 2D materials whose bonding can be best described as metallic rather than covalent?

Wikipedia's The nature of metallic bonding; In 2D says: Graphene is an example of two-dimensional metallic bonding. Its metallic bonds are similar to aromatic bonding in benzene, naphthalene, ...
uhoh's user avatar
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7 votes
0 answers
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Type of British porcelain invented around 1917-1918

Being subscribed already for 30 years on Scientific American, I recently downloaded the whole archive, and I am now going through 1914-1918. In the 26 January 1918 issue, on page 95, there is a small ...
chthon's user avatar
  • 179
2 votes
1 answer
274 views

Are there materials harder than diamond at high pressure?

It is well known that hardness and Young's modulus can change as a function of pressure. Are there any chemical substances that under sufficiently high pressure exceed the hardness of diamonds at the ...
Sidharth Ghoshal's user avatar
1 vote
1 answer
76 views

Is Li2CuSb thermoelectric?

In a fantastic 2019 Nature paper on unspervised auto-encoding (word2vec) of 3million chemistry/material science papers, the authors have found that the first 325 materials closest to the word of "...
Mario Krenn's user avatar
7 votes
0 answers
122 views

How does graphite content affect the conductivity of pencil lead?

My peers and I started an experiment to test whether we could use the conductivity of a piece of pencil lead to determine its grade (that is, whether it is 2H, HB, 3B etc.). The paper Observational ...
Jonathan Huang's user avatar
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0 answers
23 views

Are there any yellow ferrous (ideally stainless) alloys? Perhaps after heating?

I recently learned about purple gold, which is roughly 80%-20% Au - Al by weight. (It's beautiful.) I also know that Titanium will turn bright purple if heated sufficiently (probably an oxide layer). ...
L. Jones's user avatar
0 votes
0 answers
29 views

What is the most accurate way to determine the amount of water in a material from XRF and LOD-105 results?

this might seem like a silly question but I want to be sure. I have the results from an external laboratory for the bulk chemical composition (by XRF) and moisture (by Loss on Drying to 105 degrees ...
Hendrix13's user avatar
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0 votes
0 answers
29 views

NaOH etching time and temperature for Stainless Steels (SS-304) for Surface Preparation for coating

To improve adhesion of TiO2 coatings on stainless steel sample I am treating SS-304 with 1M NaOH for functionalizing the surface with metal hydroxide groups as well as increasing roughness. What would ...
Shah Fuhaid's user avatar
1 vote
1 answer
230 views

liquid (solution or polymer) with a density of more than 1.35g/cm3 and with element atomic numbers less than 9

Search for a liquid (solution or polymer) with a density of more than $\pu{1.35 g/cm3}$ and containing only elements with an atomic number less than 9. For example, a saturated solution of sugar in ...
Vladimir Magidenko's user avatar
2 votes
0 answers
52 views

Negative absorption coefficient

What does a negative absorption coefficient mean? In detail - I participated in a Synchrotron virtual laboratory. I have to analyze the results and understand what a negative absorption coefficient ...
Roni Amit's user avatar
0 votes
0 answers
34 views

For CVD diamond in a reaction chamber why does a lower temperature lead to a greater height value/thickness

I've learned that for CVD (chemical vapor deposition ) crystals in a reaction chamber, the greater the temperature the smaller the growth rate so the crystals have a smaller height. I know at lower ...
sophie's user avatar
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1 vote
0 answers
19 views

Thermoplastics crystallization during nonisothermal cooling cycles

I have tested a PAEK family polymer using differential scanning calorimetry (DSC) with heating-cooling-heating cycles under different cooling rates (heating rates remained unchanged). PAEK are semi-...
Rod's user avatar
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-1 votes
1 answer
161 views

Why are different Aluminium valencies observed from NMR and what logic can be used to normalise molar ratios of different valency atoms?

Question 1: I've observed different chemical shifts in 27Al Nuclear Magnetic Resonance (NMR) spectra of commercial aqueous sodium aluminate, indicating the presence of both trivalent [Al(III)] and ...
Hendrix13's user avatar
  • 500
1 vote
1 answer
224 views

Band structure of solids in general

As my last question (Semiconductors and their electronic bands) was badly structured, I decided to elaborate my questions a bit. As I now know, every solid/liquid forms a band structure, so all ...
Mäßige's user avatar
  • 265
3 votes
1 answer
132 views

How to determine uncompensated or solution resistance of a 3 electrode setup for IR correction?

To correct for ohmic losses from the potential drop across the electrolyte due to the distance between the electrodes, electrochemical impedance spectroscopy (EIS) is typically employed to measure ...
Daniel Leo's user avatar
4 votes
1 answer
98 views

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 ...
iron's user avatar
  • 41
5 votes
1 answer
633 views

Why I am unable to see any electrical conductivity in Permalloy nano powders?

We recently purchased some permalloy nano powders (Ni80Fe70Mo3) I checked the electrical conductivity of these powders using a multimeter which can measure resistance to the order of giga ohm's. I was ...
assasinchop7's user avatar
0 votes
0 answers
42 views

Reduction of static in lyophilized materials that have been powdered

I have recently been working with lyophilized products mostly food based items and sometimes medicinal plants (not cannabis) but I keep running into an issue when I grind the items into a powder the ...
Matt's user avatar
  • 101
2 votes
1 answer
110 views

What's the formal definition of a ceramic in chemistry?

Dictionary.com defines a ceramic as: noun (used with a singular verb) the art or technology of making objects of clay and similar materials treated by firing. (used with a plural verb) articles of ...
user148298's user avatar
4 votes
2 answers
293 views

What material is used in coating these aluminum containers for the food industry?

What is the material used to coat (some might use the term 'lacquer') disposable aluminum containers in the food industry? And can it be removed in a safe way (for the environment) with 'home methods'?...
Peltio's user avatar
  • 181
0 votes
1 answer
108 views

Is electrode reduction potential dependent on the nature of the solution(the reagents of the solution) it's dipped in?

I'm undergrad student majoring in materials science and engineering. I faced this question while studying for a course named "surface engineering of materials". This slide is a part of my ...
S M Plaban's user avatar
2 votes
1 answer
130 views

Why are certain lattices compatible with only certain point groups and not all point groups?

I will limit this discussion to 2 dimensions for ease of intuition. My understanding of the 17 crystallographic plane groups is that these 17 groups represent all the possible symmetry groups of any ...
SalahTheGoat's user avatar
1 vote
0 answers
43 views

Better Way for Crushing Coconut into 500 mesh Coal for Carbonization

I am planning to use coconut as a raw material for carbonization, but I need to crush it into 500 mesh coal. Currently, I am using a mortar and pestle to grind the coconut shell into a fine powder, ...
Becker Hija's user avatar
6 votes
3 answers
1k views

When styrofoam shrinks from pressure, why doesn't it go back to normal after decreasing the pressure?

In this article (https://oceanexplorer.noaa.gov/explorations/16carolina/logs/sep3-2/sep3-2.html) and articles like this one, Styrofoam cups were taken to the depths of the ocean in an AUV to ...
suse's user avatar
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0 votes
0 answers
120 views

At the atomic or molecular level, why are some macroscopic materials more flexible, compared to others?

Before answering this question, keep in mind that I am a 2 year Biology student, with limited experience in studying chemistry. I am going to make assumptions which I explain, feel free to correct ...
Growing6884's user avatar
2 votes
1 answer
119 views

Which gas at 15 °C and 1 atmosphere of pressure has the highest refractive index in visible light?

For my own curiosity's sake, I am attempting to find the gas that at 15 °C and 1 atmosphere of pressure in pure form has the highest refractive index on average and overall, for visible light. Assume ...
ProfessorMoreRight's user avatar
0 votes
1 answer
110 views

How can we make seacrete / biorock grow faster?

Seacrete is an interesting building material (precipitated limestone in seawater) but is quite slow to grow. https://naturalbuildingblog.com/seacreteseamentbiorock/ https://en.wikipedia.org/wiki/...
Mark Besser's user avatar
0 votes
0 answers
41 views

why does the single crystal ferroelectric have a different hysteresis curve compared to polycrystalline ferroelectric?

For the ferroelectric hysteresis curve, is there a reason why single crystal ferroelectrics have a 'hard' ferroelectric hysteresis curve compared to 'soft' ferroelectric hysteresis curve for ...
Yourhelpismuchapprecciated's user avatar
-1 votes
1 answer
161 views

Is the number of atoms per unit cell for Hexagonal Close-packed (HCP) really 6?

I am questioning whether the conventional N=6 for HCP is accurate. This question is spawned from an image in ZYbooks Material Science and Engineering textbook by Callister and Rethwisch, where they ...
TriGnome's user avatar
4 votes
0 answers
64 views

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 ...
hoggywoggy's user avatar
2 votes
1 answer
230 views

Formation of AZ91 Magnesium Alloy

I have been researching on how to form AZ91 Common Magnesium Alloy which consists of 90% Mg, 9% Al, 1% Zn, 0.3% Mn. Referring to the article at here, I have read and highlighted important text and ...
jessica smith's user avatar
0 votes
1 answer
94 views

Is it possible to physically stretch US paper currency? [closed]

This is not a facetious question. I am curious how one can physically stretch US paper currency, which is allegedly 75% cotton and 25% linen. Unlike cotton or linen fabric, paper currency does not ...
JS_Riddler's user avatar
1 vote
0 answers
88 views

Why can we use the arrhenius equation to measure the number of vacancies in a material?

In a materials science video I was watching today the prof. said we could use the arrhenius equation to estimate the number of vacancy point defects in a material. And gave the following equation: Nv =...
Dutonic's user avatar
  • 121
1 vote
0 answers
274 views

Is polycarbonate resistant to extremely cold temperatures?

I am working on a project which involves the use of polycarbonate. Polycarbonate is quite a new material to me as I haven't worked with it yet. I want to know its characteristics in detail, as it ...
Ishaan Manish's user avatar
2 votes
1 answer
71 views

What are some good synthetic samples I can make myself to start getting better at Quantitative X-Ray Diffraction?

I'm a student wanting to become an expert in quantitative X-Ray Diffraction (QXRD) to determine the wt%s of both crystalline and amorphous phases in a solid specimen. At my university I have access to ...
Hendrix13's user avatar
  • 500
3 votes
1 answer
163 views

What is a good strategy for fully quantitative X-Ray Diffraction on coal fly ashes?

I am having some trouble with fully quantitative phase identification of coal fly ashes using x-ray diffraction (XRD). Here follows some basic information about the experiment: -- ...
Hendrix13's user avatar
  • 500
2 votes
0 answers
42 views

Should I use DMA or tensile and compressive testing?

I have some polymer based samples (the exact composition is proprietary) that were additively manufactured, however the sample amount is severely limited so I'm limited on the amount of material ...
Chris's user avatar
  • 21
0 votes
0 answers
46 views

What material(s) can offer similar performance to polyurethane in a paint coating, but with less hydrogen?

We need to coat parts of an neutron instrument with a boron shielding coating. This currently is achieved using an airbrush gun with a paint mix of demineralized water, polyurethane and boron powder. ...
Stacker's user avatar
  • 39
0 votes
1 answer
350 views

In bulletproof vests, why do we use ceramic plates instead of metal?

In many articles, it has been mentioned that bulletproof vests also contain ceramic plates for extra protection. Wouldn't it be better to use metal instead? Since ceramic breaks easily.
Prerna 's user avatar
1 vote
1 answer
147 views

What chemical reactions takes place in purifying acetylene?

Acetylene produced by water on calcium carbide method contain several impurity compound, that are harmful for welding or other purposes of acetylene and needs to be absorbed from the gas mixture ...
Reza Koohpaee's user avatar
-1 votes
1 answer
62 views

Best material selection for a component containing hot saturated-level saline water with high chloride content (Polymer vs coated metal)

I have a component (Which can be seen as the attached file) and inside the component, there would be hot saturated-level saline water with high chloride content (Not shown) Considerations: The ...
MENG's user avatar
  • 17
4 votes
0 answers
50 views

Why is reported effective pore size smaller that the one declared in the name of the molecular sieve type X?

The molecular sieve type is often coded with <number><letter> combination, where <number> specifies the pore ...
andselisk's user avatar
  • 38.3k
2 votes
1 answer
584 views

Is there a liquid with refractive index 1.5 to 1.6 that is substitute to bromoform?

So I am tasked with making my countries standards sustainable, wherever possible and trying to address any of the 17 SDGs. I came across a test in a certain material specification code that uses ...
Meet Saiya's user avatar
-1 votes
1 answer
114 views

Is elongation a measure of plastic deformation?

I did a tensile test of a metallic alloy, and I want to calculate it's elongation. Would it simply be the (failure strain - yield strain)? For reference, I got the following values from the test: ...
Bob Christian's user avatar

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