Crystallization - Science method
The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Questions related to Crystallization
A first order approximation of nucleation and growth, Avrami equation can be generalized to higher and fractional dimensions with knowledge of volume and surface area of hyperspheres as well as Gamma function. Experimentally fitted fractional dimensions of Avrami equation is interpreted as predominant dimensionality of growth dimension (e.g. dimension 2.3 means mainly two-dimensional growth of crystals with somewhat inclination to three-dimensional growth), but can the same be interpreted as fractal dimension and hence an indicator of self-similarity scale for crystal growth? What is standard interpretation of avrami equation with dimensionality higher than three if experimentally found?(with explanation)
In this discussion, the dimensionality of growth of avrami equation is value of n-1 in
ln(-ln(1-Y))= ln K +n ln t
So I've been sorting through a collection of old microscope slides once used for teaching. I came across 12 slides of cockroach mouthparts mounted in what I believe is Canadian balsam, but they've gone completely opaque. The slides look a bit sparkly, so maybe some kind of crystallisation has occurred, but under the microscope it looks like a mess of fibres. We have hundreds of slide mounted in Canada balsam but no others look like this. I have no other information about the slides but I know nothing new has been added to this collection in at least 10 years so they are likely much older. I'm more curious than anything, does anyone have any ideas what might have happened?
Have I taken my area correctly to find the enthalpy of fusion Hm , so here the percentage crystallinty be Hm/Hm0 or i should consider the peak before the melting peak also and use the Hm-Hc/hm0 formula . Is this an example of cold crystallisation ?
- New PLA-based materials need to be developed to allow a good balance between environment-friendliness and product properties for engineering/durable applications.
- The blending of bio-based, brittle, and mostly amorphous PLA with semi-crystalline PAs (bio-sourced (e.g., PA11), or not (PA12)) has been reported to lead to high-performance materials (toughness, ductility, increased HDT and better thermal resistance, others).
- The low crystallinity of PLA is believed to strongly influence its final properties and to limit the applications of PLA-based products.
- Why not, the use of PLA (NA/nucleating agent) with high crystallization ability, to tune up the properties of PLA/PA blends !?
- Our paper aims to show the experimental pathways followed to produce novel PLA/PA blends using PLA(NA) characterized by improved crystallization kinetics (impressive degree of crystallinity). Moreover, it highlights with the possibility to tailor the morphology and properties of PLA/PA blends with special compatibilizers, such as epoxy styrene-acrylate oligomers.
Murariu, M.; Arzoumanian, T.; Paint, Y.; Murariu, O.; Raquez, J.-M. and Dubois, Ph.
Engineered polylactide (PLA)–polyamide (PA) blends for durable applications: 1. PLA with high crystallization ability to tune up the properties of PLA/PA12 blends, European Journal of Materials 2022, DOI: 10.1080/26889277.2022.2113986
The authors would like to share this contribution and have your opinion about the approach developed in this paper! Thank you.
(NB: Paper available open access, European Journal of Materials, Taylor & Francis Group https://www.tandfonline.com/doi/epdf/10.1080/26889277.2022.2113986?needAccess=true&role=button).
If a doped a material in a matrix. Its glass transition temperature and crystallization temperature decreases compared to the matrix but activation energy increases (Kissinger, Moynihan). Please give me the explanation for increased activation energy with decreased Tg and Tc.
I am working on the Raman spectroscopy for cancer cell lines.
For that, we seed cancer cell on the CaF2 window , fix it and contains it in the PBS. We observe the cells without coverslip.
When we see the cell in the PBS, it was fine but after taking it out of the PBS and drying, it seems like the pictures below: some crystallizations and something black dots? on the cells
What I was thought is, it is the dried salt from the PBS but I'm not sure.
So my question is
1. What is the reason in the picture below happen.
2. What should I do if I want to avoid question 1. problem?
3. Is there anything special procedure needed for the cell sample without coverslip?
I have a DSC result run from -90oC to 100oC in a heat/cool/heat cycle.
Tg, crystallisation and melting peaks are observed in the heat run. However the cool run, the crystallisation peaks are not reflected. What is the course of this from the polymer?
Dear colleagues! Have you ever studied Zr52.5 Cu32.5 Al10 Fe5 ? Could you share your experience if you have? I am interested in its phases.
I am studying the crystallization of this alloy from an amorphous state when heated, I cannot decipher the XRD analysis.
Why does Nylon, like Polyamide 66, have higher crystallization temperature after processing? We have tested the DSC (cooling rate: 20℃/min) of the Neat Polyamide 66 chips (without additives), the DSC shows the crystallization temperature is 208℃, but after extrusion or injection molding, the DSC results of the extrudates or injection molding bars show the crystallization temperature up to 230℃. Is this because of the reduction of the molecular weight after processing? But we have test the relative viscosity before and after processing, and show no significant difference.
What type of rock forms from melting cooling and crystallization and what happens when a rock buried underground is exposed to heat and or pressure?
Hi all, I set up the crystallization of protein-DNA complex for initial screen and found one crystal cluster appeared in a condition (0.1M HEPES pH7.0, 0.2CaCl2·2H2O, 45% MPD). Afterwards I added 10% glycerol and seed to optimize the crystal but it still turned out crystal clusters. How can I improve it into regular single crystals?
"I am conducting a study on PLA/PCL blends and need to determine the crystallization temperature of PCL using DSC data. Which cooling cycle data should I select to obtain this information, the first or second?"
In many research articles, it has been observed that 50/100/500 mL of solvent is commonly used for synthesizing metal oxide nanoparticles. While the metal precursors are soluble in a lesser volume of solvent than the amount used, it remains unclear why more solvent volume is used than what is necessary to dissolve the metal precursors.
Are there any correlations between solvent volume and supersaturation, nucleation, crystal growth or Ostwald ripening in nanoparticle formation?
My compound is soluble in THF ,DCM and Toluene .I am doing small scale crystallization in 5 ml vial taking 10 -20 mg of solid compound in each vial. I have already tried THF, THF/Pentane, DCM, DCM/Pentane, Toluene, Toluene/ Pentane combinations. In case of Toluene, I am getting ppt. In case of THF and DCM, even after 2nd and 3rd pentane layering I am not getting anything, not even ppt. Now what could be the solution ?What are the things that I should try ? I will highly value each of your suggestions.
Except adding a small amount of oxygen or increasing the pressure of the growth atmosphere, are there any other methods to inhibit the volatilization of Ga to maintain stable crystal growth conditions?
I have simulated crystal growth in population equations with constant growth rate by Fluent, my results are bad. In the log-normal number density diagram, the value at the peak is smaller than the standard and is created faster than the specified time. Can anyone help me?
I am looking to test activity of my crystallized protein so I am interested to know weather protein can be extracted from crystal state without damaging the viability of particular protein? and how it can be done?
Looking forward to receive helpful suggestions.
I am looking for references about measuring crystallisation and metling enthalpy of pure water with differential scanning calorimetry (DSC).
Although this seems to be quite a straightforward job, are there any challenges associated with it?
Moreover, how can the presence of ions/proteins/biological membrane fragments, dissolved in water, affect the enthalpy of those phase transitions?
With many thanks
I isolated a crystalline solid that appears to be a sugar. I need to purify it but I cannot recrystallize it because it is only soluble in water. When concentrating it, it always ends up becoming a molasses and never crystallizes. Its not sucrose or any other common monosaccharide.
How could I achieve recrystallization of this solid?
Here, this is the method :
"D-Fructose (2.16 g) is dissolved in water (4 ml) at room temperature. Boric acid (0.372 g) is then added to the thus prepared Solution, and upon its dissolving calcium carbonate (0.246 g) is added in Small portions. After carbon dioxide evolution has ceased, acetone (99%, p.a. quality; 20 ml) is added to the reaction mixture, whereupon a colorleSS oil Separates at the bottom of the reaction vessel. Two layers are separated using a separatory funnel, and the lower layer (crude boron complex) is treated again with acetone (20 MI). Upon standing at room tem perature for one hour, the mixture is triturated using a glass rod to induce crystallization, and the oil slowly Solidifies. This produces a white crystalline solid. "
I did exactly the same things written here but crystallization never occurs. Any idea ?
Hi everyone, I'm trying to crystallize a truncated DNA-binding domain of a transcription factor (Nuclear Factor I X) but its DNA-binding affinity is not optimal, therefore the complex is not very stable and its crystallization is quite tricky. I was wondering if there is one or more compounds that are known to favour DNA-protein interaction in such a way to promote complex formation and to make it more stable.
If you need more informations to answer this question, please just ask. Thank you!
Hey guys. I'm working with speed vac at the moment. But I don't know if it's the best way to concentrate the sample. Another question is whether it is normal for the sample to become viscous when more concentrated. One more question: sometimes the sample becomes saturated with other components of the buffer when it reaches a certain concentration. Can I dissolve it with water to undo the precipitation? Is there quantitative or qualitative loss of protein when it occurs?
My DSC curve (Figure1) do not show a horizontal shape. It may be related to the calibration, even though we recently calibrated the instrument.
In any case, the software offers an option in the settings tab: DSC/DTA Horizontal on/off (Figure 2). Using this mode, the curve changes to what I would expect and what is reported in the literature (Figure 3). Does this setting affect my analysis (glass transition, ...)? Can I rely on this setting to perform my analysis?
The glass transition isn't clearly visible in my curve (Figure 1), but when I apply DSC horizontal mode, I can clearly see it (Figure 3).
If I can use this setting, how/where should I set the segment (Figure 4)??
I am synthesizing coumarin-3-carboxylic acid but products are not pure. I have done crystallization to purify them , they are still impure .Besides GC and HPLC , what other techniques should I use for purification.
Hello, i did H&E staining using cryosection.
However, there are so many holes in myofiber.
Here is my protocol.
No fixation for myofiber staining
1. Dissection - skeletal muscles
2. Embed into O.C.T using liquid nitrogen
3. After completely frozen, stored at -80c before using
4. Put it into -20c cryostats 20 mins before sectioning.
5. Cut to 10μm thickness
However, it is really hard to cut without getting holes, even though the blade is brand new.
Is the problem of water crystalization or freezing time?
Please help me.
I am performing experiments with optical cryomicroscopy. My samples seem to get crystallized upon cooling at -110 degrees celsius. Also, I am able to see some crystal structures when I freeze a thin layer of the sample.
But when I passed the cross polarised light through the frozen droplet of the sample I am not able to see any image. As seen in previous articles if the sample is crystallized, I should be able to see a bright light with the structure of dendrite formation in the droplet by using the cross polarised light.
So maybe my sample is amorphous and some amount of crystals are growing on top of it as it is very concentrated (around 50 Wt%) or it is homogenously freezing?
We put titanium dissopropoxide bis (acetylacetonate) in a freezing section for 1 day. Now the chemical is crystallized and segregated with the solvent. It won't go to a mixed state by itself. What do we do to recover the chemical?
In the literature three crystalline forms (alpha, beta and gamma) have been reported for PLA. As I learnt they have different crystallization behaviour. Using the DSC technique, with a 'heat-cool-heat' programme in some samples, during cooling, I am observing a 'double peak' of crystallization, may it be connected with different crystal morphologies in the case of alpha and beta or what it can be? While conducting an experiment with quench those are not observed in cold crystallization. Also I'm not sure am I on the right way of understaning this. Thank you.
After synthesis, I kept it for crystalization in the oven for 5-7 days. I have a few questions related to this:
1) Does sonication time affect the edges of MOF
2) at what stage do we take samples for TEM: after synthesis or after crystalization
3) Amount (weight) of MOF used to prepare the TEM grid
When I was growing a single crystal recently, I found that the flux Sn residue on the surface of the single crystal was very serious. I repeated centrifugation, but it still didn't seem to work. I then soaked the single crystal with dilute hydrochloric acid (10%), but the single crystal is corroded. I think I should further improve the crystal growth process, so I wonder if there is any special way to overcome flux residue during crystal centrifugation. If you know, please let me know, thanks a lot.
Is there any optimum quantity of cristobalite (in terms of percentage) for a silica-based core to meet the requirements of turbine blade investment casting? How can I control this crystallization process?
In social drinking scenarios, my preference has always been "on the rocks", but the ex/in-plosion mentioned in the title is quite new to me. I feel it's due to unusual crystallization or air trapped or whatever, as I pour water on remnants of broken ice in the tray. Can anybody give me a scientific explanation of it?
I'm working on a protein complex crystallization. Luckily, I got some large thin layer crystals in following condition (Na cacodylate, ~10% PEG3350). However, when I tried to harvest these crystals, I found that they are very soft (just like the SDS PAGE?). Does anyone have the similar experience?
Btw, I have tried different temperatures, various PEG compositions and even additive screening, but I failed to obtain any better crystals (no diffraction pattern). How can I optimize the condition?
Thanks in advance.
Here is the crystal(?) image:
One of the main hurdles which prevent the wide-scale adoption of cryonics as a valid medical technology is the issue of water crystallization in cells which lead to cell rupture. Have there been any advances made in literature recently to address this issue? Would appreciate links to survey articles, if available. Thanks
What is the type of nucleation in Polypropylene composites containing carbon black (less than 3 wt.%) during crystallisation and recrystallisation?
Is it homogeneous, heterogeneous, secondary nucleation?
Specifically in the laser transmission welding process.
Recently I stored two samples (Cell culture supernatant) collected on two consecutive days ( i.e. day 5 and Day 6) and stored in -20 0C, But after 7 days when I saw the samples, One sample is crystallized (as expected due to low temperature) but whereas other sample is still in liquid state, I'd like to know the possible reason for this ?
I am trying to fit the atom. I tried to match PEG to density, because my crystallization condition contains PEG. But I can see the appearance of negative density after refinement. What other atom I should try ? The Electron density map is attached.
my peptide molecule having free acid and gunidine group ,How can we crystallize and what are the best solvents for crystallization ?
I am looking for fundamental level book for crystallization and its controlling parameters.
Could you please suggest any good recommended book ??
Please note: My area of research is *Struvite recovery from waste water* ?
How to extract peaks from X-ray test to calculate the crystallization ratio% of the material
As well as the size of the crystal.?
When examining X-ray diffraction of any material, are you given the standard to x-ray with the examination?
what is the new and HOT promising diluted magnetic semiconductor materials, that can have ferromagnetic and semiconductor properties close to room temperature? Wich not very difficult to realize (based on typical crystal growth techniques, availability of source)
My question is directed for research purposes, not necessarily for commercial applications.
Please share your knowledge. Additionally, If you know a good paper for this question, please tell me.
Thank you in advance.
Hi, recently I tried to do crystallization of a transaminase from Serratia sp. however, when analyzed I couldn't find Schift base or substrate in the active site nearby putative active site (K residue), but found PMP thus I predicted that the substrate was reacted during preparation and released as keto-amine. I was told that PLP-Glutamate or whatever amino acid can be synthesized before being mixed with protein before crystallization to make it observed in the structure. If you would like to share how the protocol for producing PLP-AA, it would be really appreciated. Thank you
We know that amorphous polymers having the potential to crystallize can show peaks at DSC heat flow diagrams. The question is, does a polymer such as PLA, PET, etc. with a little amount of crystallinity (lower than its potential) show the same cold crystallization behavior?
I'm currently synthesizing SrB6 powders using the combustion synthesis technique. In some of my powders I add LiNO3 to see the effect Li has in the overall properties of my particles. Interestingly, in samples having a relatively high concentration of lithium nitrate during synthesis (Sr0.5Li0.5B6, experimental concentration), there has been a formation of defects in shape of 'holes', which I believe are disruptions of the SrB6 crystal growth. Does anybody know how the formation mechanism can be studied, or how to make sure Li ions are leading to this effect?
we used Simple Reaction/crystallization method. if some one have any simple methods please share it with us?
Khandar, A. A.; Ghosh, B. K.; Lampropoulos, C.; Gargari, M. S.; Yilmaz, V. T.; Bhar, K.; Hosseini-Yazdi, S. A.; Cain, J. M.; Mahmoudi, G., Coordination complexes and polymers from the initial application of phenyl-2-pyridyl ketone azine in mercury chemistry. Polyhedron 2015, 85, 467-475.
Does the dates to evaluate the age vary with analytical methods ?
207Pb/235U dates,208Pb/232Th dates, 206Pb⁄238U ,LA-ICPMS
I am aiming to keep the humidity more or less stable in a closed chamber.
Therefore I am using a saturated salt solution in a closed chamber for that experiment.
What bugs me is, that I always end up with salts growing up on the inner faces of the vessel where I put the solution in.
The salt is, btw, growing even above the initial fill level. So the evaporation seems no to be the only reason. I guess this is related somehow to the capillary effect?
Is there a way to easily prevent this
Imagine you have some volcanic rock samples from a given area and about 30 km southwest there is an acidic pluton which is the same age as your rocks. Let's say that both your rocks and samples from the intrusion show perfect fractional crystallization trend on the La vs. La/Sm diagram with only several samples deviating from the trend line. Their common La/Sm ratio is constant, in this case, and let's say it is around 7, while La contents vary from 20 to over 60 ppm with one sample reaching up to 90 ppm. In this case, it seems reasonable to argue that they evolved together from the same source, I guess.
My question is, if we assume a hypotethical situation where the La/Sm ratio of the volcanics is, say, 25, whereas that of the samples from the acidic pluton is 7, would that imply that they evolved from different source regions?
I am carrying out crystallisation experiments for lysozyme. The method is the following: dissolve 73.6 mg/ml lysozyme (lyophilised or crystalline powder) in 0.1 M sodium acetate buffer, and dissolve 80 mg/ml NaCl in 0.1 M sodium acetate buffer. Mix both solution with a ratio of 1:1 to achieve a final crystallisation composition of:
- 0.1 M sodium acetate buffer
- 40 mg/ml NaCl
- 36.8mg/ml lysozyme
-->the supersaturation ratio should be around 10
These crystallisation condition led previously to crystallisation: solution stayed clear after mixing all components and well-built crystals were visible with the first 3 hrs.
However, I am using new lysozyme powder batches (lyophilised or crystalline powder) and immediately after mixing the solutions (NaCl with lyophilised or crystallised lysozyme), the solution turns cloudy. Instead of crystals, after 1-3 hours only small precipitate or aggregated proteins are occurring. I just purchased the new lysozyme powders very recently but cannot explain why they don't crystallise out anymore?
Anybody an idea?
Many thanks, Frederik
Often multiple attempts for crystallization failed to get a single crystal XRD to determine the structure of the compound.
I initially get some crystals of my protein with the space group P 21 21 21 and a decent resolution (2.4 Angstrom). With this dataset MR didn't reach a proper solution.
Changing the temperature for crystallisation, but using the same condition, I obtained some crystals with a different unit cell and space group (C 1 2 1). The highest resolution I could obtain was 3.3, but the software easily found a MR solution using the same model.
I reprocessed the old data and checked all the statistics from the old dataset and I keep obtaining again the same results, so MR keeps not working. I am also sure that the old crystals are from my protein, since the sample was pure and the crystals present the typical yellow colour of the cofactor. I would like to find a solution with the first dataset, since its has a way higher resolution.
Any suggestion/similar experience?
I have synthesized yttrium nitrate solution from yttria by adding HNO3. Now I want to crystallize it into solid form. I tried doing it the way CuSO4 is crystallized. But I am getting ammonia gas, and no crystallization. So what is the procedure?
I currently started my thesis in crystallography. I am unable to crystallise my non-membrane protein with His6-tag. I use the proper conditions for the protein though. Is there a way to do so, or enzymatic cleavage would be an easier solution in my case?
I did XRD of my powder alloy samples, I got major peak of all samples with different concentration but beside major peaks some small distortion peaks, I think the high entropy alloy powder hasn't been well crystallized after 45hrs mechanical alloying (Ball milling). How can I improve the crystallinity of my powder alloy sample.?
Can Anyone help me to understand these graphs? I did TG/DTA/DSC for a ZrB2 based ceramic composite(5 samples). I Have got mass gain for all the samples and the DSC followed the same trend for all five samples. ReChecked the test procedure and equipment, there was no problem. If Oxidation would be the reason, Can i take DSC's Sign change point as the Crystallisation point? Do ii have any melting region here?
Our team wants to saparate inorganic salt (such as NACl, NA2SO4, LOE) from the brine, and at the same time we wish to predict experimental results by simulation. Do you have any suggestions? Thanks in advance.
Stock concentration: 1mg/mL
Metatopolin solvent: 1N KOH
Metatopolin diluent: DDW H2O
STOCK VOLUME : NOT more than 10 mL
I was setting up crystallization tray for ubr1 box. This is my first time ever doing crystallization and I am having trouble telling if what I am getting crystals since it looks nothing like what's been shown to be in class. Please help. Thanks in advance.