Materials Chemistry - Science topic

If you're interested in the acceptance rates for the Journal of Materials Chemistry C or any other Royal Society of Chemistry (RSC) journal, I recommend visiting the official RSC website or the specific journal's website for the most up-to-date information. Journals often publish their acceptance rates or may provide information on their peer review process, which can give you a better understanding of their publication standards.

Both Origin software and X'Pert HighScore software can be used to determine the hkl values of a crystal structure. Here are the steps to follow for each software:

Using Origin software:

1. Open the data file in Origin software and select the graph containing the diffraction pattern.

2. Click on the "Peak Analyzer" button in the toolbar.

3. In the Peak Analyzer window, select the peak of interest by clicking on it.

4. In the "Peak Information" tab, note down the "2Theta" value and the "Counts" value for the peak.

5. Use the Bragg's law equation (2dsinθ = nλ) to calculate the d-spacing value for the peak. Here, n = 1 for first-order diffraction. λ is the wavelength of the X-ray used in the experiment.

6. Use the d-spacing value to calculate the hkl values for the peak using the Miller indices formula (hkl = [n1d1,n2d2,n3d3]).

Using X'Pert HighScore software:

1. Open the data file in X'Pert HighScore software and select the diffraction pattern.

2. Click on the "Peak Fitting" button in the toolbar.

3. In the Peak Fitting window, select the peak of interest by clicking on it.

4. In the "Peak Information" tab, note down the "2Theta" value and the "d-spacing" value for the peak.

5. Use the Bragg's law equation (2dsinθ = nλ) to calculate the wavelength of the X-ray used in the experiment.

6. Use the d-spacing value to calculate the hkl values for the peak using the Miller indices formula (hkl = [n1d1,n2d2,n3d3]).

Dear Maria Jabri

You can use the following link to find indexed journals:

Good luck.

It is a China made low-field NMR Company, which has the special products for crosslinking density measurement.

There are two new ones:

DEACON® 8875-THIN

I have just found this interesting paper where they have discussed the comparison between Gold and Platinum as the electrode material when fabricating TiO2 memristor.

Also, you can make memristor with NTC (Negative Temperature Coefficient) thermistors, which can be really chip.

Please let me know if you have already found some other chip materials to fabricate memristors.

For conventional spectrometers, solid sample holders are available. But to calculate quantum yield, an expensive integrating sphere will be necessary.

If you just want to check the emission wavelength as rough qualitative analysis, a plate reader would help. Normally can found in bio-lab using 6, 12...96 wells. Remember to grab a "dark plate", and load ur sample into it for plate reader to analyze. The plate reader measures luminescence in reflective fashion, so ideal for solid sample as well.

As for the suspension way, I think Dr. Tang Ben Zhong's group always dissolve their compounds in THF first, and slowly increasing the water content until the compounds were partially immiscible in the solvents. In this way, when the suspension came (partially immiscible), they could observe the AIE (aggregation induced emission) of their compounds.

I personally recommend the solid holder or plate reader. Sometimes the suspended particles get to huge or turbid and results in serious scattering of excitation light.

*Dark plates can avoid weird scattering light compared to normal transparent plates.

*Some old plate readers measure absorbance only, so be sure there's a "luminescence mode" there.

Theorical density Is 6050 kg/m3

Hello, I found that the solvation method you used was SMD model combined with ONIOMPCM, namely SCRF =(SMD,solvent=water, ONIOMPCM = X). I would like to ask if this combination is correct? Where did you get this key word?

Extrement important

Dear Umair Nisar

Differential voltage analysis has been applied to various lithium-ion cells, to study degradation reactions (side reactions) as a function of cycle number. Standard cycling data is used to calculate either dQ/dV or dV / dQ, which is then plotted against the voltage. In dQ / dV plots, the peaks represent phase equilibria, whereas, in dV / dQ plots, the peaks represent phase transitions. Differential capacity (dQ/dV) analysis allows you to observe what is happening in a battery (including degradation, failure mechanisms, changes in chemistry) in much greater detail than can be observed using aggregate statistics like capacity, energy, and efficiency per cycle.

Conceptually, dQ/dV describes the incremental capacity going into our out of a device over a given voltage increment (some also prefer to use the inverse, differential voltage, dV/dQ). Differential capacity can be derived from raw time series current and voltage data, or accessed directly using a Battery Intelligence platform such as Energsoft. The differential capacity plot displays dQ/dV on the vertical axis, plotted against potential on the horizontal axis, with the loop in this plot showing one charge-discharge cycle.

dQ/dV Differential capacity curve Where there is a peak on the curve meaning the charge and discharge curves have a voltage platform, and different peaks represent different electrochemical reactions.

use NPAR

Microstrain in nanoparticles can arise from the surface restructuring or due to the localized disturbances in the lattice omprakash rajpoot

Muhammad Asim Khan see here:

Suggested Readings

thanks for your important question

A. H. Harvey, “Semiempirical correlation for Henry’s constants over large temperature ranges”, AIChE Journal, vol. 42, pp. 1491-1494, 1996.

Dear Matthew J O'Hara, Thank you for sharing the article.

You may want to check also:

Dear Omer, for using both of these websites, you should sign in via your institution in advance, otherwise they do not provide you with any search options. The following discussion is concerning your problem with Scopus and can help you to solve it.

The following webpage is the sign in page of Web of Science but as I told you, you should log in through your institution panel.

Good luck!

these attachments will be useful

as per phase diagram of CaO-Fe2O3, mixed and heat in muffle furnace as indicated temperature

What is the Chemical compound of sodium silicate?

Dear Dr. Charitha B P ,

in addition to the important refences proposed by Dr. Juan Genesca ,I suggest you to have a look also at the following, interesting paper:

-Effect of ph and chloride concentration on the corrosion of duplex stainless steel

Yunan Prawoto, K. Ibrahim, and W. B. Wan Nik

ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 34(2) (2009)

Available, on RG as full text, at: https://www.researchgate.net/publication/238739911_Effect_of_ph_and_chloride_concentration_on_the_corrosion_of_duplex_stainless_steel

My best regards, Pierluigi Traverso.

A very useful link to find the thermodynamic parameters ( △G°, △H° and △S° ) form experimental data.

https://youtu.be/ZT6Nwf5wdG0

How to apply Langmuir adsorption isotherm. A complete guidance ..

titanate base catalyst such as TIPT(tetra isopropoxide titanate) and TNBT(tetra normal butyl titanate) is an excellent catalyst for this issue.

for the first time, RAZIN ADVANCED MATERIAL and CATALYST DEVELOPMENT produces these catalysts. see the following link.

There are a few things to distinguish here, i.e.

1) full equilibrium partitioning among all phases (and making sure that all phases present are really known and not overlooked, for instance because they are very small), considering full thermodynamic equilibration for all of the elements (viz the fast ones such as C, N, H etc and the slow ones such as Mn and Si etc) - this does not happen very often. Most low temperature equilibrium partitioning coefficients are extremely difficult to measure.

2) equilibrium partitioning among phases only for fast diffusers; rest same as above

3) partial equilibrium partitioning only at the interface, but decaying concentrations far away from the interface, due to kinetics.

4) equilibrium partitioning NOT only among the two (or more) phases, but also among the interface itself and the adjacent phases (the interface is a thermodynamic trapping site of its own, due to the adsorption isotherm, and may elements in steel also partition to them (and not only to the phases)).

All of the resulting partitioning coefficients depend substantially on kinetics and composition of course.

Some of them can be obtained directly from multi-component phase diagrams (full equilibrium required, is practically never the case in steels) and some not (kinetics, then u have to use dictra of phase field etc).

In all of these cases exact values for multi-component partitioning coefficients can experimentally usually only be obtained by using atom probe tomography.

Taking partitioning coefficients from the concentration profiles very close across the hetero-interfaces is particularly helpful as the atoms can maintain local equilibrium (equal chem. potential across the interface) with only a few atomic diffus. jumps - when probing far away from the interface partitioning coefficients are usually wrong, due to kinetics.

Good luck.

Here are some references, but this is a wide and really complex field…

some example pictures are also attached, just to give a rough impression

etc

Dear Hameem,

If you are adding de-ionised water to stop the reaction, make sure that you add the water in small volumes. Since the reaction mixture involves concentrated sulfuric acid, an exothermic reaction is produced with water which might alter your oxidised graphite. I would add a small volume at a time and wait for the temperature of the mixture to decrease before adding another portion of water. I hope this helps.

Dear Zeineb Ben Rejeb, which amine you mean, is is the one of APTES? If so, the answer is no except its influence on the pH. In the following RG links mainly the first one, a detailled procedure is presented. Important to control the pH and ethanol/water ratio. My Regards

I will recommend COMSOL Multiphysics . It does take care of chemistry and mechanical properties

Dear Staish Kumar,

Mixing calcium chloride and potassium dihydrogen phosphate with sodium chloride could be the solution for your complete dissolution. pH can be adjusted. Potentiostat/potentiometer can be used if one wish to see the antibacterial and fluid effect if any.

The general understanding is the solubility of hydroxyapatite is greatly affected by the pH of oral fluids: In general, a more acidic environment causes hydroxyapatite to become more soluble, while a less acidic environment makes hydroxyapatite less soluble. The more undersaturated plaque fluid and saliva is, the greater the amount of dissolution. Integrates size effects and surface energy control into the overall reaction rate does matter a lot for comprehensive dissolution. Dissolution is induced by the formation of pits and continues with the spreading of their stepwaves. However, only the larger pits (of size greater than a critical value r*) are active, with stepwaves contributing to dissolution and the spreading velocities are also dependent on the pit sizes, decreasing with decreasing pit size. Size effects dominate the reaction when the crystallite sizes are of the same order as r*, resulting in self-inhibition of dissolution and even reaction suppression. Only when the pits are larger than a critical size, do they contribute to dissolution. Usually, biomaterials selection such as nano-sized mineral particles, their basic building blocks and synthetic sparingly soluble biominerals such as HAP behaves similarly.

Experimentally, the dissolution experiments can be initiated by the introduction of known amounts of crystal seeds, conducted using magnetically stirred (generally 450 rpm) double-walled Pyrex vessels thermostated at 37.0 ± 0.1 °C. Undersaturated solutions can be prepared by mixing calcium chloride and potassium dihydrogen phosphate with sodium chloride to maintain the ionic strength at 0.15 mol L−1. The pH can be adjusted to the desired value using diluted solutions of either potassium hydroxide or hydrochloric acid. Titrant addition can be triggered by a incorporating glass and reference Ag/AgCl electrodes. During dissolution, the electrode potential can be constantly compared with a preset value and the difference, or error signal, activated motor-driven titrant burets. And, hence a constant thermodynamic dissolution driving force can be maintained.

Ashish

Hlw good day I want to make DES choline cholride +MAA with molar ratio 1:2 can any one share the precise calculation for these moaor ratio..thanks

KMnO4 is an oxidising agent. If conc. of KMnO4 very then it will affect the preparation of GO.

Dear all, please check the following document. My Regards

I think, between  600 -700 °C  temperature is needed to initiate the iron reduction

Hi

I totally agree with Michael

​Kind regards,

Actually, the question is how to measure the cholesteric pitch in a more appropriate way. It depends on particular range. If the liquid crystal has the reflective band in a visible spectral range, you can restore the pitch value from spectroscopic measurements (see, for instance, L. M. Blinov, Structure and Properties of Liquid Crystals). If the pitch is in the range from a few to several tens of microns, you can use the optical microscope for studying the previously mentioned Grandjean Cano wedge or LC droplets suspended in a liquid (Solladie, G. & Zimmermann, R. G. Liquid crystals: a tool for studies on chirality. Angew. Chem., Int. Ed. Engl. 23, 348–362 (1984)). I suggest to be careful with fingerprint texture, because the line width can vary in dependence with the cell thickness.

May I ask how do you test your glassy carbon electrode in SEM? How do you load the sample in SEM

Dear Prof. Amit Agarwal

For band structure calculation or energy-k calculation you might follow this general procedure more than a unique equation:

1. First, the hamiltonian of the periodic structure should be the input information (you beed to know it).

2. Second, calculate the eigen-energies of the hamiltonian at each k-point.

3. Third, plot the energy-k dispersion.

the following ResearchGate thread is very useful:

also this external link:

I agree with Curtis_Guild

Jingjing Xue

Thanks for the attached references!

Is it possible to have better luminescence when you have a mixture of phases (cubic and hexagonal) compared to a pure hexagonal phase? Maykel Manawan

From my point of view you can try the two materials in your laboratory and choose the method which gives better results. As my expectation as the two solutions are utilized to obtain good working solar cells then you can use either or both then choose the better one.

Best wishes

A half of year ago, with this large duration Na2S·9H2O can be exposed to high temperature, humidity or oxygen if the bottle is not completely sealed. The crystals appearance becomes increasingly opaque at higher temperature. Also, the Na2S·9H2O salt may absorb water vapour until it was completely molten/dissolved. Oxygen from the air may react with the warm salt sample resulting in the formation of sodium sulphite crystals. A preliminary recommendation is to handle this salt in an oxygen free environment (nitrogen gas blanketing).

Cu powder being added to the Na2S to remove hydrogen sulfide formation during Preparation methods for Na2S·9H2O and a black deposit of copper sulfide on top of the sodium sulfide hydrate salt. So, it Cu impurities in the salt may found and make it black with time.

Sure... The segmental molecular weight (Mc) of a crosslinked polymer is conneted to its shear or elastic modulus. In principle, if you can evaluate G' or E' in the rubbery plateau, then the Mc value can be calculated following the formulae:

1) G' = dRT/Mc; and 2) E' = G'/[2(1+nu)], where G' is the shear modulus, E' the elastic modulus, d is the density of your material, R is the gas constant, T is temperature and nu is the poisson ratio.

You will not obtain a a value for the corsslinking density, but an averaged molecular weight between crosslinked segments. Please, remember: when highly crosslinked, smaller Mc values and higher G' and E' values...

SALUT!

Tony (sanchez@hfm.tum.de)

The advantages of the Pechini method lie in the steric entrapment of cations and the prevention of segregation. That is to say cation immobilisation. For this reason, the Pechini method is attractive for the synthesis of nanocrystalline oxides containing multiple cations sites, or single cation oxides where homogenous substitution or doping is desired.

By forming a polymer resin by esterification with EG, cations are homogeneously dispersed and segregation of multiple phases is inhibited.

By ordinary hydrolysis and condensation in typical sol-gel methods, the formation of multiple phases can often arise as the result of different hydrolysis and condensation kinetics for the different cation species. This is avoided in the pechini method by chelation (usually citric acid) and subsequent networking (polymerisation)

This following paper is suggesting that alpha and gamma alumina have similar thermal conductivity (35 W/mK).

However, gamma should have different thermal conductivity considering its porous structure?

Reactions can be of different types: addition, substitution (nucleophilic or electrophilic), acid-base reactions [adduct formation, coordination complexes], metathesis, transmetallation etc., One should examine the nature of the compound and what interactions with solvent will enable the compound (solute) to dissolve in it.

Some time reactions can be carried out in solid state by using finely divided particles (grind well in a mixer or using pestle-mortar to increase the surface area) using ball milling (popularly known as mechanochemical method).

Also one can use a solvent in which the reactants are insoluble but still reaction can happen.

If needed use more solvent and generate suspension and reaction can occur.

If it is sparingly soluble in methanol, still reaction can be carried out.

If it is ionic complex, try to substitute the anionic species with a better anion and that should help. If the complex is an anionic species, try to encapsulate the cation using polyethers, cryptands etc. to make it soluble in polar organic solvents.

Dear Madni Shifa see link:

In silica gel, the physically adsorbed water can easily be removed when kept in an air oven at temperature around 150 degree centigrade temperature for 2-3 hours. Time duration may vary depending upon the spreading of silica gel. The indicator cobalt(II) chloride added to indicate the hydrous form of silica gel (pink) and anhydrous form (blue) should indicate dehydration of silica gel from anhydrous to anhydrous form.

Asim Idrees Thanks, This is what i was trying to look for, I am new to this field.

Thanks to all

Thank you for highlighting the pages, Nin Nan

Here is a possible explanation to your question.

Ceria, when used as an MIEC in electrodes, under reducing conditions (anode) doped ceria is partially reduced from Ce4+ to Ce3+ . This induces n-type electronic conductivity, which can lead to partial internal electronic short circuits, and this problem increases with increasing temperatures. See Fig. (Fuel Cell Fundamentals by R O Hayre) where the electronic conductivity at the anode side will be greater than the ionic conductivity for temperatures greater than about 550C.

The disadvantages of doped ceria can be partially solved by adopting a multilayer approach where, for example, a GDC layer facing the cathode is combined with another solid electrolyte (e.g., YSZ) facing the anode. However, multilayer cells also have performance problems due to formation of reaction products with low conductivity at the interface between the electrolyte layers, as well as the mismatch in thermal expansion between the electrolyte layers, which can result in microcracks.

So these reaction products, or change in reaction mechanisms for Doped Ceria at the cathode side is what is mentioned in the papers you shared. And it seems like they have come up with an optimal doping concentration of 30% for lowest ASRs for doped ceria used at the cathode side.

Hope this answers your query

regards

Waqas

Hello dear Sahil Thareja,

Plaese have a look to the following steps (as an example) for asymmetric cell configuration Prepare two electrodes with your powder. You probably need a polymer binder and carbon black in addition to your material to fabricate the electrodes. The weight ratio of the active material: binder: carbon black is usually 85:5:10. 2) Prepare the PVA gel electrolyte (need to slightly heat the solution and constantly stir it to fully dissolve PVA powder). Generally, 1 g PVA powder per 10 mL water. 3) Dip your two electrodes in the PVA gel electrolyte. Let the electrodes be fully soaked by the gel electrolyte. Take the electrodes out and hang them for a while to let excessive gel flow down. 4) Sandwich a piece of a separator in between the two soaked electrodes. The separator can be wetted by the gel electrolyte prior to the assembly. 5) Wrap the sandwiched structure with parafilm or other films to well seal the device. This sealing step is critical as PVA can gradually dry when exposed in the air which results in capacitance loss. 6) Gently press the two electrodes to improve the filtration of the gel electrolyte and the contact between the two electrodes.

Standard photoresists that are used in the LCD industry. For example the Shipley products: http://microchem.com/products/images/uploads/BPR_100_UL-PF04N022R4.pdf

Dear Abdenour Guerraoui

Please find rules and regulations of your university, how it is possible to have co-supervisor from outside country. if yes, then you may find well suitable persons

Did you finally find a way to synthesize it?

As a related topic to this discussion, I would like to ask whether it is possible to dop Eu2+ to an assembly containing Au and TiO2 where the doping mainly to the TiO2. In some papers it is shown that it is possible to do this. But there are also contradictory statements. Can someone provide me some insights?

Yes ofcourse because unless the surface is polar where is question of its interaction with water which is polar. May it be surface or bulk that does not matter much.

I am not sure what you exactly mean. However, in general, using ultrasonic equipment could largely improve the dispersion of your particles within a solution.

If your polymer is organic (no char residue) and your filler is inorganic, one possible way would be to burn it over the resin degradation temp in a furnace, once the resin has degraded the residue weight would be the amount of filler. Wouldnt be 100% accurate but should be good enough for an estimate.

Dear Pan,

There is something basic with the effect of light with suitable wavelength on the sensitivity S of the gas sensor. By definition the sensitivity of the gas sensor is the ratio of Rg the gas sensor resistance to an identical reference sensor R0.

So, S= Rg/Ro. R0 = L/sigma0 A, with L the length and A the area and sigma0 is the initial conductivity. Sigma= q u n, sigmao= qu n0

Then it results that the sensetivity S= n0/n,

Assume that n = n0-dn, where dn is the chang due to the gas adsorbed.

Finally we have S= n0/( n0-dn)= 1/ (1- dn/n0)

One would like make the ration dn/n0 as high as possible.

This accomplished by making n0 as small as possible such that dn can be an appreciable part of it by the adsorbed gas.

So, shining light will not help much but in contrary can make the sensor less sensitive.

Best wishes

phenolic resin is a brittle polymers and have good thermal properties due to the presence of aromatic structure in their polymers chain, So in order to degradation with out using heat y using strong solution of sodium hydroxide.

This reference and those that accompany it could help you:

Electron-trapping and energy localization in insulating materials. Technological impact of space charge electron-beam characterization

AIP Advances 8, 095228 (2018); https://doi.org/10.1063/1.5047673

You may consider to dissolve melamine and urea (perhaps 1:1 mol/mol) in hot formalin (37% wt/vol of formaldehyde in water/methanol sol.), while melamine can transform to methyl melamine.

Agree with the above. If there is a linear dependence of peak current with sweep rate then it usually means an adsorbed species is involved. This is a good recent paper in the Journal of Chemical Education.

Watch your units on your graph, sweep rate is mV / s.

Theoretically, the oxide film on Al is soluble in low pH solutions. However, in practice, the cathodic reaction, hydrogen reduction, results in a diffusion layer with a pH at the surface that is much higher than the bulk solution pH. This retards the rate of dissolution and can even bring it to a virtual stop if it enables a uniform passive film to form. In high pH solutions, the reverse is the case and dissolution is accelerated, instead of retarded, by the pH shift that accompanies hydrogen evolution. In less pure Al, the inclusions become dedicated sites for the hydrogen reduction reaction restricting the pH shift to their locations, and this allows dissolution to continue at anodic sites. So, I would try two things: (1) connect the Al wire to a Pt wire so that the cathodic reaction can occur on the Pt, and (2) try less concentrated acid. Keep in mind that vigorous hydrogen evolution is a potential safety hazard and proper precautions should be taken.

Hi, Prasons, do you still remember the way how to get rid of excess POCl3. i am facing the same situation as you did. As the reaction happened under nitrogen protection, so i just have to switch the valve of schlenk line from nitrogen purge to vacuum and keep the temperature around 80 degree C?

Dear Priya,

Try to use solvothermal technique, it may help to reduce the temperature as well as improve the degree of crystallinity.