Questions related to Powders
I reconstituted some lyophilized actin powder from the manufacturer, made aliquots and freeze dried the aliquots for long term storage.
However, reconstituting them in the same buffer and at the same concentration results in an insoluble precipitate, impervious to any amount of vortexing and overnight shaking.
Any advice on how to solubilize the protein is appreciated
"About 0.5 g of ground sugarcane bagasse powder mixed with 0.1 g of ferrocene was placed in a crucible and put
directly into a muffle furnace at 300 °C for 10 min under atmospheric conditions."
Instead of ferrocene, use iron II oxide?
Wood based activated charcoal powder (2 ~ 20 μm) was subjected to heat treatment at 850℃ for 4 hours under a nitrogen atmosphere. After cooling down to room temperature, remove from the furnace. After encountering air, activated carbon powder undergoes spontaneous combustion.
What is the cause of this? How can it be avoided?
P.S. I am very sure that when taking out the activated carbon from the high temperature furnace, the activated carbon has already cooled completely.
I have two powder patterns collected at 300 K and at 10 K. The low temperature diffractogram shows some reflexes that are not present at room temperature. Is it possible that these are just some kind of artifacts?
I am doing Elisa using Alkaline Phosphatase and Pnpp. Pnpp is in powder form, I have made pnpp solution in a concentration of 10mg/10ml using phosphate buffer..
But the problem is I am not getting result after 30 min incubation of adding pnpp as substrate..it's taking long time more than 5/6 hrs to develop yellow colour for positive samples...why it's is happening..please help me
I would like to conduct a doping experiment.
How does this work?
1. mix two powders in one solvent
2. making two precursors and mixing them together
And how do I calculate the doping concentration?
Is it correct to calculate the mass of each solute in moles and then express it as a percentage?
Why does stirring make salt dissolve faster and does crushing salt into a powder before dissolving it in water increase the reaction rate?
I am trying to synthesize single-phase CaFeO2. The reactants are CaFeO2.5 and a two-molar excess of CaH2, the powder was mixed for more than 30min, pelletized, and vacuum-sealed in a pyrex tube. Finally, the pyrex tube was reacted at 553K for 7days.
Unfortunately，all the productions are Fe.
I want to brominate three phenyl groups in one molecule by using Fe powder as the catalyst. but I always end up in very small yield. instead, mono and dibromo product were produced. is there any tips for working on bromination reaction by using Br2 and Fe powder? thank you.
I have powder sample of methyl ammonium bismuth iodide and I want to use it as the active layer of perovskite solar cell. How can I make film of this sample? In n-i-p configuration I am planning to use ZnO as ETL.
Please advise me on calculating the homogeneity of two mixed powders with ImageJ by SEM images. Articles, guides, and real case studies are welcome. I want to automate the image analysis process as much as possible.
Thanks for all suggestions!
I try to mold 2% sio2+PMMA nanocomposite powder into the tensile specimen. The hot press temperature is 130 C and I usually add 2 to 3.5 Ton bar on the mold for 15min ( preheat the mold, put the mold and sample in the hot press for 3 min without P, and then apply pressure and then let it cool down at room T).
I use the same condition for pure PMMA and I don't have any bubbles on my samples however for the nanocomposite, I try different things such as the above method or adding some powder, applying P, removing it, and adding another layer and letting be in the hot press for 15 min but non of them work and I still have bubbles in my sample.
Any thoughts or tricks to get rid of bubbles?
I want to understand better what happens with the results of a XRD test on a pure Nickel powder with a Cu tube. If possible, I would like to discuss the possibilities of analyzing a sample with, and without a Ni filter.
How should I prepare a suitable solution to find absorbance using a uv spectroscopy device?
I have obtained tio2 nanoparticles (anatase) and I want to prepare the powder I obtained by making a suitable solution.
note: the device cannot read the values correctly at all
I have L-Lysine powder from Sigma Aldrich. Based on MSDS, the L-Lysine powder can easily be solved with water, but in my case, some hydrophobic parts can't be solved. It influences the UV-Vis spectra. What is the hydrophobic component, and how to solve them?
I am trying to find the maximum acceptable limit of moisture content in powders for oral suspension, is there a reference that lists acceptable moisture content in pharmaceutical dosage forms on which I can rely?
- Clay, solid sample (solid crystalline powders), can be swollen by water.
- Which kind of spectroscopy and the corresponding sample preparation?
In the liquid phase sintering of Tungsten-Iron-Nickel powder compacts, could the presence of carbon (between 0.6% and 1.5%) significantly influence the final microstructure by altering the diffusion and the precipitation of W in the Fe-Ni matrix?
I study ethanol electrooxidation on Pd, which is supported on carbon using cyclic voltammetry.I prepare the working electrode by adding 5mg of powder to 33µL Nation and 467µL of ethanol followed by 20 min sonication.Then I add 20µL (200µg powder) of the ink into the glassy carbon electrode surface.Problem is some of the ink get dried on the ceramic outside surface of glassy carbon.I can not control or accuartely define how much of the slurry has dried on the glassy carbon and how much was dried on the ceramic surface.That is why I am obtaining non-reproducible CV results every electrode experiment I run.I use the same electrolyte concentration, scan rate, reference electrode, and same area of working electrode. The only different thing is the working electrode, which is from the same material ink. Theoretically, it should give identical or very similar CV results.
PMMA does not dissolve in water. I tried a lot to dissolve it, but the amount of polymer is reduced to milligrams.
I did XRD of steel slag powder with copper source. The sample contains iron phase. I was getting a very elevated XRD peak data with very high noise such that the peaks are not distinguishable. The step size is 0.01 degree, and the sample run-time was 30min. The sample size was less than 180 microns as I had sieved out using 180micron mesh. I am skeptical about the fluorescence effect but how can I still manage out to collect XRD data using copper anode only as I do not have accessibility of XRD device with cobalt anode.
What is the chemistry behind this.And how to recharge that powder.
Anyone have any idea regarding if addition of metal powders in pdot enhance there electrical conductivity? I see some research papers with insitu reduction of Nanoparticles. But would just addition of powders procured separately and added to PDOT-PSS have the same effect?
I got a pure ciprofloxacin powder from sigma Aldrich , and I didn't get information from the manufacturer about the potency of the antibiotic
only the following information
how can I calculate its potency ?
I am interested to understand the ASTM/Standard test methods and instruments which are being used for the Water absorption and Oil absorption analysis of Reactive alumina or fine alumina oxide powders.
Thanks in advance.
As essential oils are in liquid form, they are usually weighed in milliliters. However, in various studies, it is converted to powder and measured in milligrams by following different methods that can result in the loss of its vital activities.
I have synthesized ZnO and NiO nanoparticles with size around 40 and 35 nm respectively without any capping agent. Now they are in powder form. Please suggest me, how can I make stable dispersion of these NPs (individual)?
Please suggest from your experience.
Hello, I am trying to model laser powder bed fusion bed process for Inconel 718. Can any one kindly provide me any reference of how the laser absorptivity of Inconel 718 powder changes with respect to different variables? Or is there any equation which relates absorption to different parameters? ( Like wavelength or laser power or temperature). Thank you!
Is any co-relation between highly strained, strainless samples to see or observed melt pool cross-section after laser powder bed fusion process.
I purchased collagen IV powder from Sigma and the website says to dissolve in acetic acid, PBS or water. As I didn't have acetic acid I tried to dissolve it to 1mg/mL in PBS but the collagen has aggregated. Should I let it dissolve at room temperature or in the fridge? Is it still efficient?
Thank you for your help
I have added PVC to my bacterial culture broth to see the degradation potential of bacteria toward the microplastics. The PVC, I have used is small powder granules. After proper incubation, I would like to stop the experiment. What would be the ideal method to separate the microplastic from the culture broth and analyze it for possible weight loss and further characterization?
I am trying to define the peaks of my synthesized powders and while researching how to do it properly I came across several youtube videos. After baseline corrections and smoothing the graph, one of the videos went through an extra step where they stripped k-alfa2. My question is, is this step necessary? If yes, then can someone explain why? I couldn't find any further information regarding this.
I produced a fire crucible, but unfortunately, it cracked after two uses. How can I improve its performance? I think the problem is in not choosing the correct granulation of raw material particles
Basically I have powder samples of High Entropy Alloy Powders which are produced by mechanical alloying using Ball mill. I need microwave absorption property characterization of my samples but it's not possible to measure properties of powder directly. So for that I need to form die of powders, with hollow Centre and 3.05mm inner diameter and 7mm outer diameter. Thickness about 3-4mm. Can anyone guide me regarding die formation? I need to prepare this to measure microwave absorption property of my powder alloy samples. Below jpeg file represents die schematics.
Danial Nawaid Siddiqui.
if we are using a substrate for holding the CNTs during upward sputtering since CNTs are in powder form, which Substrate can be used without affecting the purity of CNTs and how to separate metal decorated CNTs from substrate in powder form without affecting the decorated metal nanoparticles?
The protocol we use is the two-step desolvation method using acidic pH, but it seems that instead of a powder we seem to get fibrous cotton-like material instead. Has anyone else experienced it and how were you able to solve the problem? Thank you very much!
Dear researchers, i hope you all are doing well. Currently i am working on Cu and Ni foam based electrode for MXenes based supercapacitors and my material is in powder form. But i have no idea to make working electrode for supercapacitors from them. Is there any friend who worked on Cu or Ni foam before or still working. Can you guide me the whole procedure ?
your quick and positive response will be highly appreciated. Thanks
I needed profile distribution of alpha alumina powder 1 micron and gamma alumina powder 50 nm used in electrochemical polishing kits. any leads will be appreciated. Thanks in advance.
I synthesized Mn-Zn ferrite powder. In the FTIR spectrum, there are four peaks at wavelengths less than 1000, two of which are related to Fe3+_O2-. What are the other two related to?
I’m looking into getting copper sulfate for our cell culture incubator. Across most of the companies we buy from, costs of copper sulfate vary greatly. Where do you order yours from? Do you just order the powder form? Let me know when you can! Thanks.
I need to mix 16 powders of of dissimilar sizes and density in batch sizes of 2-6 Kg. These powders are usually of 20-50 microns in size. I understand there are different types of machine that use different technologies (Ribbons, V-Tumbling, Paddling, cyclones, etc.) to achieve the homogeneous distribution of the chemicals. What is the nature of machine that is best suitable for this job?
I have carbon-coated Sn (Sn@C) nanoparticles in the powder form with the size ranging from 20-100 nm. I want to transform these core-shell structures to yolk-shell or hollow ones, so I need to obtain extra void in the core (Sn) without damaging the carbon shell onto the Sn layer. I have found a couple of paper about Sn etching or Sn-based alloy etching. I see that the Sn etching solution are HNO3 and water solution in 1:1 ratio, some of them HNO3: MetOH/EtOH solution in 2:1 ratio or like 0.5 M HNO3, but I haven't seen reliable procedure or like etch rate something. Since I never worked with it I wonder if someone can give me tips for safe handling such as which component I add first and what is the max temperature for it?
If you have any recommendation how to etch Sn safely and in a controlled manner, I would be grateful.
I want clarification on the type of wood powder to opt for as an adsorbent for removing Copper and Lead from soil. Also which sieve size will you recommend, is 60 mesh sieve size okay?
PVDF has both an alpha phase (non-conducting crystalline phase) and a beta phase (conducting crystalline phase, responsible for the piezoelectric performance of the polymer). PVDF films can be fabricated by dissolving PVDF powder in a solvent. the films are then characterized using XRD. The alpha phase shows an XRD peak of around 17.6 degrees and the corresponding plane is (100), whereas the beta phase shows a peak of around 20.5 degrees, but two planes have been assigned together for this peak position i.e. 110/200 planes as reported in the literature. How is this possible? How the two planes can contribute to the same peak position? [Note: The angle between the 110 and 200 planes is 60 degrees]
I have gone through several literature where all of them prepare powder from nano particle solution after preparation of nanoparticles solution using plant extract. If we think about the application of nanoparticles, Why we create powder rather using the liquid solution (Aqueous solution can be considered) ?
We know salicylic acid powder is insoluble in water. Literature say that they added salicylic acid solution to the water based slurry to detect the *OH radicals, which are generated due to Fenton reaction in the slurry. I have purchased salicylic acid powder from Sigma Aldrich. But I do not know how to dissolve it in the water based slurry. Because literature dose not say the details. They do not make the issue clear. I am seeking help from the experts.
I am mixing very viscose silicone and powder together using a speedmixer. What is the best way of measuring homogeneity of the mixture across different sampling points in the mix? any suggestions will be appreciated.
A colleague recently told me that, when preparing formaldehyde solutions from powdered paraformaldehyde, she keeps the temperature below 65 degrees C. Why is that necessary? We boil the solution in a closed tube.
This is an XRD pattern of limestone powder constating of Quartz, Calcite, Dolomite mainly.
Is there chance you can help checking and finding the phase quantification of the below XRD pattern?
An approximate numbers will surely help me to interpret some of my work. I have noted the first intense peaks for those 3 major phases of the minerals in the limestone.
Calcite is more than 40 % and Quartz is below 10%. Any approximate numbers based on intensity ratio is great.
Please have a look. Any of your input is very much helpful.
I have collagenase from sigma product code c9891 100mg,Type IA, 0.5-5.0 FALGPA units/mg solid, ≥125 CDU/mg solid, For general use
I do not understant from the product data sheet how many units are per mg (U/mg)....
How can I make a 30U/mL solution? How much buffer should I add to what quantity of powder to obtain 100mL at 30U/mL solution?
I would appreciate your experience. Thank you!
I want to make a aqueous extract of using raw green leaves. Normal procedure is using dried powder. So, is it possible? If possible, what will be the procedure?
I am working on a chemical reaction that requires anhydrous conditions, but I currently don't have molecular sieves. Is it possible if I use silica powder (after activation) to absorb moisture from the reaction, or will it affect the reactivity of my reactants (polar compounds), and if not, what are other alternatives that are safe to use in the reaction instead of molecular sieves
I made Fe-Pt alloy by arc melter and it was too hard to make a powder for PXRD(Powder X-ray Diffraction).
Could you recommend any method to make a powder of hard metal for PXRD?
I'm planning to check PXRD using bulk piece(not-grinded, only sliced). Could I get a reliable XRD pattern compare to powder?