Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [materials]

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

1
vote
2answers
10 views

Why isn't 'chemically-strengthened glass' made with potassium carbonate? To begin with?

Instead of making potassium-strengthened glass by creating ordinary soda-lime glass first, then replacing the sodium atoms/ions with potassium by putting the glass in a bath/solution of potassium ...
2
votes
0answers
45 views

Which material are piezoelectric buzzers made of?

Which material are these buzzers made of? Does it depend on the manufacturer or they all are made of the same material? The Wikipedia page does not say anything about the material. I found some ...
2
votes
1answer
37 views

Suitable coating material for protection of sensors

I'm building a moisture/temperature sensor for outdoor use in soil. It uses capacitive sensing for moisture and an NTC thermistor for the temperature. It's going to be used for vegetables so food ...
0
votes
0answers
33 views

Equilibrium concentration of point defects in solids at sufficiently elevated temperature

Equilibrium concentration of point defects in solids is defined as $\chi=\exp(\frac{\Delta s}{k_B})\exp(\frac{-\Delta h}{k_BT})$. At high temperatures, may be even higher than melting temperature of ...
0
votes
0answers
18 views

Why hydrate metal precursors used in synthesis of metal-organic frameworks, MOFs?

To synthesize metal-organic frameworks materials it mostly uses the hydrate metal precursors, so why should we use this kind, and can we use the anhydrous salt?
2
votes
0answers
35 views

How can we conduct reactions for insoluble materials?

I am working on metal organic polydehra topic to synthesize new metal-organic cages or other based frameworks. I want to conduct postsynthetic modification for one cage, but the solubility is very ...
5
votes
1answer
87 views

What is wrong with storing deionized water in glass containers?

I have heard that in general storing deionized water in glass bottles is ill advised and that it is better to use plastic. Additionally this is especially important for water used in ICP. I have ...
2
votes
0answers
27 views

Where can I look for a short chain photopolymer?

I am by no means an expert in this field, so please be patient with my explanation. I am looking for a photopolymer with very specific properties. I am not sure how realistic it is to find such a ...
0
votes
0answers
15 views

Properties of poly sponge vs. poly foam?

Question: the aspects in which I'd like to know how the poly sponge compares to the poly foam are: Stretchability (e.g. compression, then rebound back to original shape). Durability as they keep ...
3
votes
1answer
29 views

How can I prevent my spin-coated silica thin film from cracking when I heat it up?

I am spin-coating a porous silica solution on a glass microscope coverslip, and then heating the resulting thin film to $\pu{350 °C}$, in an attempt to create a thin film of porous silica sol gel. I ...
4
votes
1answer
49 views

Do self-growing hydrogels grow and strengthen infinitely?

Recently, there was a publication [1] (/., YouTube) on self-growing materials using mechanoradically-generated double-network (DN) hydrogels, closely resembling self-strengthening of muscles. We ...
-1
votes
1answer
64 views

It is possible to create any metal? [duplicate]

This question just popped up in head. There are many things which we are good at. We are good at: constructions. build stuff. destroying things. repairing things. cleaning. But I want also to know, ...
39
votes
4answers
16k views

Why can a diamond be broken using a hammer if it's the hardest natural substance known?

I've heard that diamond is the hardest natural known material but, on Google search, I found that it can easily be broken by a hammer as it's not tough. So, what is difference between hardness ...
1
vote
2answers
46 views

Materials used in cooktop heating element, and reason for black appearance

I have been interested in the structure of heating elements/coils used in cooktops. I am referring to something such as in the following picture: I have a cooktop at home with such elements, and at ...
2
votes
2answers
50 views

Directional emission from molecules

This might be a silly question (probably is). When a molecule absorbs it has a transition dipole moment, a measure of how strongly a certain transition will interact with light will depend on how ...
3
votes
2answers
364 views

Why is FEP transparent and PTFE not?

fluorinated ethylene propylene (FEP) is close relative of poly(tetra-fluoroethylene) (PTFE), both only contain fluorine and carbon atoms,both have very similiar properties yet FEP is relatively ...
2
votes
1answer
95 views

Does alumina become transparent at high temperatures?

Consider a normal opaque alumina crucible. I've heard that they become transparent at higher temperatures and therefore, are not appropriate for high precision DSC (caloric) measurements. The reason ...
2
votes
2answers
114 views

Which is the cheapest plastic that retains its structure at 85 °C or higher temperature?

In an academic project, I need to protect some electronics components from heat (around 85 °C). I am searching for both a cheap plastic film and a cheap plastic to be used in a injection molding ...
1
vote
1answer
47 views

Liquid that burns in a vacuum [duplicate]

This may seem like a silly question, but is there a flammable liquid that could oxidise itself, so it could effectively burn in a vacuum?
1
vote
3answers
2k views

Why are calorimeters often made of materials with low specific heats?

When building calorimeters, a material with a low specific heat is often used (such as Styrofoam, aluminum, etc.). However, why would a material with a low specific heat be preferred? My thought ...
2
votes
1answer
43 views

What does it mean for a higher glass transition temperature in terms of crystallinity?

The glass transition temperature is associated with amorphous regions in a polymer. If I have observed in a lab experiment that polymers with a higher glass transition temperature tend to have less ...
4
votes
1answer
206 views

Which invariant reactions are congruent?

I am studying the concept of incongruent melting and invariant reactions. I was wondering, would all the invariant reactions that I show below be incongruent? As I understand it, we can only have ...
1
vote
1answer
150 views

Equation to find specific gravity (or density) from a solution of sugar and water

Is there an equation or simple way to calculate the final density of a solution made from x grams of sugar and y liters of water? And would it work in reverse? if we have y liters of water at z ...
1
vote
1answer
100 views

Can I use pure zirconium as an anode in electrolysis?

I read that zirconium is not very reactive even when supplied with a current in an electrolyte. If I had a sizable piece of it, can I use it to perform electrolysis for rust removal of items? Would it ...
-1
votes
1answer
48 views

Help with Carbon Fibre

I'm having trouble finding articles about carbon fibre that don't contradict other articles. I just have a few questions about the atomic structure and the intermolecular and intramolecular forces. ...
1
vote
1answer
41 views

What material most closely resembles/emulates dog's excrements? [closed]

Please get me right - this is no joke! Our engineering team has a terrible contract - we need to find a way to get height from which some dog excrements were dropped judging by what was found on ...
1
vote
1answer
66 views

How to correctly mix solutions?

Imagine you have two ingredients - 45 grams of 60% ethanol, and as much water as you wish. The only accurate tool you have is a scale, which measuring error is up to $\pm \pu{1gram}$. How would you ...
0
votes
2answers
67 views

Hazards of trivalent chromium and hexavalent chromium

I am examining a material safety data sheet that reports on trivalent and hexavalent chromium in chemical films. It covers each type where it is used in a product individually. Is there a practical ...
0
votes
1answer
36 views

Composition of Portland Cement before Hydration [closed]

I recently came across a question- Which of following chemicals is NOT found in Portland Cement? A. Di-calcium silicate B. Tri-calcium silicate C. $\ce{CaSiO3}$ D. $\ce{Ca3(PO4)...
1
vote
1answer
30 views

What is spatially and chemically heterogeneous materials?

Follow this paper, Structural analysis of humins formed in the Brønsted acid catalyzed dehydration of fructose They explained "humins are spatially and chemically heterogeneous materials." I found ...
1
vote
0answers
66 views

Long-term durability of linen vs polyamide vs polyester?

What is the comparative long-term durability of linen vs polyamide vs polyester when exposed to oxygen, but not sunlight? I assume that linen, polyamides (Nylon) and polyesters will all oxidize and ...
1
vote
0answers
56 views

PTFE-to-PTFE or PTFE-to-Copper pressure seal

I am currently working on an engineering project with a friend. Without giving too much away, I have two parallel strips of Zirconium-Copper alloy sandwiched between an upper and lower piece of smooth ...
1
vote
0answers
39 views

Is there a known crown ether analog to fullerenes?

It is well known that endohedral fullerenes have potential quantum computing applications example 1,example 2, and example 3. But, currently they are too expensive, around $167 million per gram at ...
-1
votes
1answer
69 views

What is the definition of a component in a phase diagram?

I have been trying to understand the concept of a component in relation to phase diagrams in my materials class. I have tried searching online and found that the definition is supposed to be that a ...
2
votes
0answers
23 views

Study long term properties of two polymers

This is a material-science question, and I didn't know where else to put it. I (and two others) are mechanical engineering students and are starting a bachelor's thesis which involves some material ...
1
vote
0answers
72 views

What material can be used as scraper in a chemical reactor?

I am having a 10L reactor built using SS316 for Plastic Pyrolysis. TEMPERATURE : 550C I would like a scraper to clean the char that forms on the reactor's inner layer. Teflon scraper is available ...
-1
votes
1answer
35 views

How would ceramic coating inside the reactor affect heat transfer? [closed]

With the ceramic coating, would I be able to get its internal temperature raise upto 520. I would like to get a reactor fabricated for plastic pyrolysis. The temperature would maintained around 520C. ...
1
vote
1answer
543 views

How does PEDOT:PSS work (mechanism) in Organic Electrochemical Transistors?

I have a question about the fairly fundamental theory behind the application of PEDOT:PSS in an organic electrochemical transistor (OECT) device. As at least I understand it, the ...
1
vote
1answer
137 views

Is matter really divided in two categories?

Page 1 of almost every Textbook start with the ordinary divison of matter in 2 categories: Substances and Mixtures. Substances, or Pure Substances sometimes, are defined as a form of matter that ...
4
votes
1answer
274 views

What type of gloves should be used while diluting sulfuric and hydrochloric acids?

What type of gloves should we use on hands while diluting sulfuric and hydrochloric acid? Can we use these gloves in chemistry lab to handle other acids?
6
votes
0answers
215 views

Thermophysical properties of liquid Galden LS 230 between 25 °C and 230 °C

I'm looking for thermophysical properties of Galden LS 230, a liquid polymer (PFPE) produced by Solvay (https://www.solvay.com/en/markets-and-products/featured-products/Galden.html) at temperatures ...
3
votes
2answers
89 views

Material that changes solubility when electric potential is applied [closed]

I am looking for a material witch is easy to deposit in thin films and which changes its solubility if a electric potential is applied. Do you know of any such materials ? EDIT: This is for what I ...
1
vote
0answers
34 views

Can such material exist? [closed]

Can a solid material exist, such that it shatters if you hit it lightly (with a solid object) but it deforms and doesn't shatter if you hit it hard (say with a hammer)?
1
vote
1answer
81 views

Uncertainty in measuring the mass of the palm oil and the base in saponification

I am a student coming from the domain of mathematics, and I am working on error analysis and uncertainty, but I have a question in the domain of chemistry. I am studying the effect of the ...
7
votes
1answer
548 views

What gas has the highest refractive index? [closed]

Coming from this answer on the Worldbuilding stack, I'm trying to find a gas with a high refractive index in the visible light wavelengths. The highest index on this site, is chlorine at 1.000773. Is ...
0
votes
1answer
43 views

Material with refraction index similar to Si

I am looking for a material with a refractive index over the visible spectrum , which is close to the refractive index of Si, but which does not oxydise in air. Do you know of any such material ? ...
1
vote
1answer
244 views

Isotopic mass to density

I want to figure out/calculate the density ($\pu{g/cm3}$) of the various isotopes, here $\ce{^109Ag}$. I know it's isotopic mass is $\approx109$ and calculated the number of particles/gram. But I ...
1
vote
0answers
30 views

Extraction of Activated Carbon from Lignin

I'm currently working on a research project which involves the extraction of activated carbon from lignin. I'm already aware of the method of preparation using an alkali along with lignin products but ...
2
votes
0answers
516 views

How can I extract cellulose in plants using acids?

Me and my classmates are doing a research project about the extraction of nano cellulose from plants to form a biocomposite, which can be a material to form an effective biodegradable material. We've ...
3
votes
1answer
94 views

Why does a protein crystallize with a specific salt but not with another?

So I am conducting an experiment and I do not understand this super fundamental part. I know salting out works via solubility, and I know crystallization works via ordered structures. But could ...