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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Why upon melting of PEO between crossed polars colours appear?

Crystalline PEO when under crossed polars shows distinct Maltese cross pattern. Being birefringent, when polymer crystal align with the polarizer or analyser it shows extinction regions (effect known ...
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Fixed Nitre - How does it differ from commercial K2CO3? [closed]

Fixed Nitre is chemically regular K2CO3 but it is prepared by two methods Mixing charcoal to molten KNO3. Detonating a mixture of KNO3 and K2CO3 adding little at a time to red hot crucible. This is ...
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65 views

Why n-alkanes can be found in organic solvent extract of rubber?

Sorry for the confusing title, I didn't know how to describe this better. So, if we douse rubber, say, a bicycle tire or a certain type of rubber glove, with organic solvent (n-heptane), we can find n-...
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How to get rid needle clogging on electrospinning of PLA/PCL/PMMA/Collagen?

For my thesis research, I dissolved PLA and PCL in chloroform: methanol (3:1), PMMA (350.000 MW, 13 wt%) in acetone, and collagen in acetate acid--and then, I mixed them together. The problem is when ...
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123 views

Is “density per unit volume” something?

I was reading articles on the preparation of shellac-based composites when I encountered the following statement (in ref. 1): Wood flour and fibres are interesting because of their low cost, good ...
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24 views

Gelifying hydrogen peroxide

What substances could be used to gelify 60% hydrogen peroxide? I imagine anything organic like agar would be broken down by the radicals. I tried looking up what dentists use and the only thing that ...
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1answer
85 views

Making Lyophilized Cake Lookalike using household ingredients

I'm working on a machine learning model to identify flaws in vaccines in lyophilized cake form. To train the model, I need a number of samples that look something like this: I have vials, but I'm ...
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1answer
162 views

what is the structure of bamboo kun?

There are claims that the bamboo fiber has inherent antibacterial properties due to "bamboo kun". However I could not find anywhere what is the chemical composition of this "bamboo kun" and also no ...
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99 views

What is the origin of the Quadratic factor in calculation of XRD peaks?

Whenever we are to calculate the d-spacing(for cubic system) in XRD peaks with reference to Quadratic Factors we do that with the help of the formula $$\frac{1}{d_{hkl}^2}=\frac{h^2+k^2+l^2}{a^2}.$$ ...
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36 views

Fick's second law atomic diffusion question [closed]

I have a question about diffusion and i'm not sure how to tackle it. A new processing method is being tried for a lithium battery cathode material -LiCoO2. the process leaves the ceramic oxygen ...
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24 views

Platinum-carbon calayst in autoclave

Is it safe to treat platinum-carbon catalyst in an autoclave at 200 °C for 24 h in inert (nitrogen) atmosphere? If no, can you suggest safety measures?
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Which transparent plastic to use for electrolysis of dilute sulphuric acid

I plan to do an experiment which involves the electrolysis of dilute sulfuric acid (1 M or 1 mol/L). I would like to carry it out in a long transparent plastic container (easier to handle and clean). ...
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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 ...
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58 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 ...
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1answer
92 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 ...
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19 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?
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37 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 ...
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1answer
286 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 ...
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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 ...
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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 ...
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1answer
47 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 ...
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1answer
69 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 ...
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74 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, ...
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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 ...
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2answers
60 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 ...
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2answers
56 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 ...
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2answers
674 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 ...
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1answer
116 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 ...
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2answers
498 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 ...
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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?
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3answers
4k 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 ...
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1answer
45 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 ...
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1answer
386 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 ...
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1answer
378 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 ...
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1answer
136 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 ...
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1answer
60 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. ...
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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 ...
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1answer
99 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 ...
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2answers
95 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 ...
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1answer
43 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)...
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1answer
31 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 ...
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96 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 ...
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57 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 ...
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41 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 ...
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165 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 ...
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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 ...
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97 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 ...
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1answer
43 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. ...
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1answer
800 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 ...
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1answer
169 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 ...