Science topics: Chemistry
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Chemistry - Science topic

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds.
Questions related to Chemistry
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Hi there,
It is clear that we use many types of hydrophilic additives containing hydroxyl groups in the PES dope solutions to provide a less hydrophobic membrane.
Is there any physical interaction between the sulfone group of PES polymer chains and hydroxyl groups of hydrophilic additives in the membrane matrix?
Best regards
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Dear Foroogh Khodadadi, if you are suspecting Hydrogen bonding between SO2 and OH groups, sulfone group is a poor H-forming group due to the orientation of H-donor-acceptor counterparts. Please check the following documents. My Regards
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The Chemistry of reaction and detailed mechanism leading to the formation of the green nanoparticle would be greatly appreciated.
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Synthesis of nanoparticles basically needs a metallic ion (Ag+) and a reducing agent (sodium citrate) for reduction of metallic ion to Neutral Ag. In chemical synthesis, the use of synthetic chemicals cost high and not environmental friendly. after the synthesis of Nano particles it produces many harmful chemicals. In order to make nanoparticle a cost effective and environmentally sound method, green synthesis is prioritized. In green synthesis we use the plant or animal extracts as a reducing agents for nanoparticle synthesis. The plant and animal extracts are not so expensive to use because we can use the west products of plant materials like peels of vegetables or fruits (E.g. -Pomegranate peels) and also it does not produce any harmful chemicals after synthesis. Also there are other advantages of using green method of synthesis of nanoparticles.
Hope you question is somehow answered.
Thank You
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I am trying to imagine a problem where particles in water climb/coat onto an air bubble in bulk water. Is this even possible?
If yes, if we form equations, will that have the same surface tension as water-air (say 25 C) along with a force balance?
To complement this: Yes, using solid bubbles (say beads of glass) or simply a glass slide, we can make the water stick to it using surface tension
Your inputs are much appreciated! Thanks:)
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Earth, wind, fire and water were the ancient elements.
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In Becke's B3LYP hybrid functional, Fock exchange is being mixed with Slater LSDA exchange (and then plus gradient correction), plus correlation expressions. But what LSDA exchange parametrization is used?
  • It appears to me that Becke in his DFT Thermochemistry I paper (J. Chem. Phys. 96, 2155 (1992)) uses the VWN parametrization, being the then modern alternative to the older Perdew-Zunger version.
  • Then in his Half-and-Half paper (J. Chem. Phys. 98, 1372 (1993)), he apparently switches to the then recent Perdew-Wang 1992 parametrization.
  • In his 3-parameter hybrid (DFT Thermochem III) paper (J. Chem. Phys. 98, 5648 (1993)) he seems to only comment on correlation being taken from the PW 1992 parametrization and not mention which LSDA version he uses for the exchange part, presumabely still the standard Slater exchange (E_X ~ int n_(alpha)^(4/3) + n_(beta)^(4/3) dr.
So which LSDA parametrization is used nowadays in B3LYP? Did people stick to the VWN version from Becke's initial paper or did they switch to the more modern PW version as Becke probably did? Or do different implementations in program packages use different versions?
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There are some references that might prove helpful:
Sholl. D.S. and Steckel, J.A., Density Functional Theory: A Practical Introduction, Wiley, 2009. Page 218.
Here some parameterizations are specifically mentioned.
(3) The Bretonnet article is attached.
I hope you may find something of these to be of use.
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So I was running an IR on a sample that I had thought (or rather hoped) was phenol (hydroxy benzene), but what came out was either trash and noise, or I simply did not have phenol. My professor and I were quite stunned as it showed no signs of organic peaks at all, especially no -OH peak near 3100. My professor suggested to run my reaction again, but sadly I do not have the reagents on hand at the moment and it will be some time before I get them.
The reaction I ran was one taken from an old book on recycling benzene waste. When I conducted it, I took a mixture of nitrobenzene and benzene waste and I added a random amount of relatively pure Fe2O3 and 13% Hydrogen Peroxide to try and oxidize anything in the waste to phenol or hydroxynitrobenzene. After I treated it with NaOH to make a phenoxide salt and then I did some work up to isolate. What I was left with was a nice white crystalline salt (or so I thought). But the IR says it contains zero organics as far as our IR machine can tell, and our machine is used daily if not hourly, and is kept in great condition.
If someone could help me understand what I have or teach/lead me how to identify inorganics, that would be very appreciated.
Because the attached picture is possibly hard to see small details, I have listed the peaks as well.
Peaks:
-610.07 cm^-1 transmittance: 60%
-635.08 cm^-1 transmittance: 79%
-1091.13 cm^-1 transmittance: 64/65%
Rizal Awaludin Malik After rereading my notes, I have come to realize that I distinctly changed my procedure because I was having trouble with the Iron Oxides previously mentioned. My pseudo-procedure looks more like this:
Fe + 2HCl -> FeCl2 + H2
2FeCl2 + Cl2 -> 2FeCl3
FeCl3 + H2O2 (13% aq) -> Fe(OH)3 + Reactive Species
And my idea was to combine the benzene/nitrobenzene wastes I had with the final reaction in the scheme (combining the reactive species) to try and produce hydroxylated benzene and nitrobenzene.
Some notes from my notebook leave me further puzzled:
"Smell of nitrobenzene and benzene has totally disappeared, and lots of gas evolution. A red precipitate (likely iron oxides) has formed at the bottom of the beaker. There is no longer 2 layers (2 phases) and the yellow color of the solution is very faint, where it was quite deeply colored beforehand."
I'm not sure what exactly happened but I have done a little bit of searching and came across Hexaaqua iron (III) chloride, which may be what I have crystallized out.
To explain further, after the whole reaction was completed, I filtered off the red precipitate and tried to crystallize out whatever product I had formed. When I did so, I was left with a pure white free-flowing powder. The powder seems hygroscopic in nature.
I will likely try this again, with pure benzene to see if the same result occurs.
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Aidan Bradley as we know the range 1085-1050cm-1 is for strong-
C-O stretching. This is a primary alcohol. You have a pick is the 1091.13 cm-1 so it is more likely that is indicating the presence of C-O stretching. The other two picks are 636.06cm-1 and 610.07 cm-1. We know 690-515 cm-1 range indicates the presence of strong C-Br stretching, which is a halo compound. So those two picks are indicating the presence of C-Br stretching.
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We are interested to establish a Chemistry Research Institute/Department here at Sukkur Institute of Business Administration University (SIBAU), Sukkur, Sindh, Pakistan. Suggestions and Guidance will be highly appreciated.
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Indian Institute of Chemical Technology - https://www.iictindia.org/
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There were five pretests administered to both groups. Each pretest represents a different topic in chemistry (Matter and Its Interaction). In lesson 1, the experimental group has significantly higher group means than the controlled group. In lesson 2, two groups have statistically equal group means. In lesson 3 and 4, the control group has significantly higher group means than the experimental group. In lesson 5, the two groups have statistically equal group means. In the overall pre-summative test, the two groups have statistically equal group means.
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Hello Mohamed Khedawy. Using a statistical test of normality as a precursor to a model that assumes normally distributed errors1 is not a very sensible thing to do, IMO. Normality of the errors is most important when n is small, and becomes less and and less important as n increases. And tests of normality, like other tests, have low power when n is low and increasing power as n increases. Therefore, your test of normality has low power to detect non-normality when non-normality is most important, and too much power to detect it when it is not very important. This is the main point of a short conference presentation I gave on this topic some years ago:
1 Notice that it is the errors (not the Y scores) that are assumed to follow a normal distribution. Note too that nothing in the real world is truly normally distributed. The best one can hope for is approximated normality. See George Box's classic paper, Science & Statistics. Fortunately, linear models are quite robust to non-normality of the errors. Independence (and homoscedasticity) of the errors is far more important than normality of the errors, particularly as n increases.
Box, G. E. (1976). Science and statistics. Journal of the American Statistical Association, 71(356), 791-799.
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Dear science community!
I need your help, please!
I`m totally disapointed and at a loss!
In 2020 (at the end of October) there were the IOP Conference Series: Materials Science and Engineering (ICoSiET 2020). Me and my colegues took part in these conference. As the result (like a result of any other conference) the thesis collection should have been published (at the 4th quarter of the 2020)). Unfortanately, these collection still haven`t publised (despite the fact that 2021 is already at its end).
So, I wonder, if there are anybody, who know something about this situation? Maby there are any of those who also waiting for their thesis?
We have wrote lots of messages to the organizators and the head of the university (in which this conference took place) but they stoped to respond us.
I think this situation shows disrespect for the conference participants. And I believe that such situations should be inlighted in our community!
Thank you, for your attention!
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I perfectly understand your indignation! Our entire laboratory invested money in the conference. It is very unpleasant that they deceived us, they still do not get in touch. Here is one of the organizers of this conference: https://www.researchgate.net/profile/Andri-Pranolo
Here is a link to this year's conference: https://icosiet.org/2021/
Be careful not to be deceived either.
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I have extracted polyclonal antibodies with PEG 6000 in PH (5.2, using HCL to adjust PH). Using dialysis membrane (12000 cutoff), the PEG was successfully separated from the polyclonal antibodies and I purified my product.
Currently, I am trying to establish product in industrial scale. But, I do not know what can be used instead of dialysis membrane in industry scale???? What is your suggestion? Could you please kindly help me regarding to the separation of PEG from polyclonal antibodies (180 KDa) in industry scale??????
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I have done that by an ammonium sulphate precipitation, PEG is insoluble in AS solutions and forms an organic layer on top after centrifugation. You remove first that, then the aqueous phase and retain the protein pellet. Quick, simple and cheap.
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Dear all
What are the best books in chemistry that can be used for curriculum design "i.e. for Materials Chemistry"?
Please write the name of the best books that you read/know in the field of "chemistry"? General Chemistry, Organic, Physical Chemistry, Inorganic, Biochemistry, Polymer synthesis, Polymer Chemistry, Computational Chemistry, Solvents and Solvation theories, Analytical Chemistry, Electrochemistry, etc [...] and Chemistry Laboratory Design.
Thank you very much
- - -
* Additional comment:
You can, also, send to me links (or the books' front page photo) or E books (PDF or any) here or in private message. Thank you!
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Top 3 Chemistry Books | Personal Statement Reading
  • 1) Periodic Tales: The curious lives of the elements - Hugh Aldersey-Williams.
  • 2) Obsessive Genius: The Inner World of Marie Curie - Barbara Goldsmith.
  • 3) H2O: A biography of water - Phillip Ball.
  • Bonus: Periodic Videos.
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HI All,
I'm doing a survey as part of an Audacious program (https://www.startupdunedin.nz/audacious), which essentially is a StartUp initiative at Otago University. I'm curious to understand what level of programming do biologists these days need during their day to day research.
For all the biologists out there here are some questions to start the discussion on this topic:
1) Have you done any programming till date? If so which language did you use and for what purpose?
2) How have to overcome programming limitations? For example, did you get the work done through bioinformaticians, or sought help from your programming friend, etc?
3) Have you used online biological databases for your research? If so, which one?
4) How much of artificial intelligence have you used in your research? Do you see AI potential in your current work?
If you have anything else to add, please feel free.
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Please have look on our(Eminent Biosciences (EMBS)) collaborations.. and let me know if interested to associate with us
Our recent publications In collaborations with industries and academia in India and world wide.
Our Lab EMBS's Publication In collaboration with Universidad Tecnológica Metropolitana, Santiago, Chile. Publication Link: https://pubmed.ncbi.nlm.nih.gov/33397265/
Our Lab EMBS's Publication In collaboration with Moscow State University , Russia. Publication Link: https://pubmed.ncbi.nlm.nih.gov/32967475/
Our Lab EMBS's Publication In collaboration with Icahn Institute of Genomics and Multiscale Biology,, Mount Sinai Health System, Manhattan, NY, USA. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/29199918
Our Lab EMBS's Publication In collaboration with University of Missouri, St. Louis, MO, USA. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/30457050
Our Lab EMBS's Publication In collaboration with Virginia Commonwealth University, Richmond, Virginia, USA. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/27852211
Our Lab EMBS's Publication In collaboration with ICMR- NIN(National Institute of Nutrition), Hyderabad Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/23030611
Our Lab EMBS's Publication In collaboration with University of Minnesota Duluth, Duluth MN 55811 USA. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/27852211
Our Lab EMBS's Publication In collaboration with University of Yaounde I, PO Box 812, Yaoundé, Cameroon. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/30950335
Our Lab EMBS's Publication In collaboration with Federal University of Paraíba, João Pessoa, PB, Brazil. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/30693065
Our Lab EMBS's Publication In collaboration with collaboration with University of Yaoundé I, Yaoundé, Cameroon. Publication Link: https://pubmed.ncbi.nlm.nih.gov/31210847/
Our Lab EMBS's Publication In collaboration with University of the Basque Country UPV/EHU, 48080, Leioa, Spain. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/27852204
Our Lab EMBS's Publication In collaboration with King Saud University, Riyadh, Saudi Arabia. Publication Link: http://www.eurekaselect.com/135585
Our Lab EMBS's Publication In collaboration with NIPER , Hyderabad, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/29053759
Our Lab EMBS's Publication In collaboration with Alagappa University, Tamil Nadu, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/30950335
Our Lab EMBS's Publication In collaboration with Jawaharlal Nehru Technological University, Hyderabad , India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/28472910
Our Lab EMBS's Publication In collaboration with C.S.I.R – CRISAT, Karaikudi, Tamil Nadu, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/30237676
Our Lab EMBS's Publication In collaboration with Karpagam academy of higher education, Eachinary, Coimbatore , Tamil Nadu, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/30237672
Our Lab EMBS's Publication In collaboration with Ballets Olaeta Kalea, 4, 48014 Bilbao, Bizkaia, Spain. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/29199918
Our Lab EMBS's Publication In collaboration with Hospital for Genetic Diseases, Osmania University, Hyderabad - 500 016, Telangana, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/28472910
Our Lab EMBS's Publication In collaboration with School of Ocean Science and Technology, Kerala University of Fisheries and Ocean Studies, Panangad-682 506, Cochin, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/27964704
Our Lab EMBS's Publication In collaboration with CODEWEL Nireekshana-ACET, Hyderabad, Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/26770024
Our Lab EMBS's Publication In collaboration with Bharathiyar University, Coimbatore-641046, Tamilnadu, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/27919211
Our Lab EMBS's Publication In collaboration with LPU University, Phagwara, Punjab, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/31030499
Our Lab EMBS's Publication In collaboration with Department of Bioinformatics, Kerala University, Kerala. Publication Link: http://www.eurekaselect.com/135585
Our Lab EMBS's Publication In collaboration with Gandhi Medical College and Osmania Medical College, Hyderabad 500 038, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/27450915
Our Lab EMBS's Publication In collaboration with National College (Affiliated to Bharathidasan University), Tiruchirapalli, 620 001 Tamil Nadu, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/27266485
Our Lab EMBS's Publication In collaboration with University of Calicut - 673635, Kerala, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/23030611
Our Lab EMBS's Publication In collaboration with NIPER, Hyderabad, India. ) Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/29053759
Our Lab EMBS's Publication In collaboration with King George's Medical University, (Erstwhile C.S.M. Medical University), Lucknow-226 003, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/25579575
Our Lab EMBS's Publication In collaboration with School of Chemical & Biotechnology, SASTRA University, Thanjavur, India Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/25579569
Our Lab EMBS's Publication In collaboration with Safi center for scientific research, Malappuram, Kerala, India. Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/30237672
Our Lab EMBS's Publication In collaboration with Dept of Genetics, Osmania University, Hyderabad Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/25248957
Our Lab EMBS's Publication In collaboration with Institute of Genetics and Hospital for Genetic Diseases, Osmania University, Hyderabad Publication Link: https://www.ncbi.nlm.nih.gov/pubmed/26229292
Sincerely,
Dr. Anuraj Nayarisseri
Principal Scientist & Director,
Eminent Biosciences.
Mob :+91 97522 95342
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I extracted the essential oil and I found that my major compound represent 95 % of the mixture and only less than 5 % as minor constituents ( 20 constituents).
I'm I allowed to take my major constituent as starting material to perform chemical reactions?
Do the minor constituents representing only 5 % will not disturb the obtention of the desired compound?
I would like to insert some functional groups to increase bioactivity.
Any help in this regard will be appreciated.
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Dear Alexander Sinko, well done ! 95% !!!, as dear Dr Erdal mentioned , I advise you to be careful to remained 5% ( 20 components), you can use Column Chromatography or Solvent extraction........
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What kind of functional groups do we need to insert by the synthesis in organic chemistry to have anti-cancer activity in perspective?
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It's not usually the functional group, but a pharmacophore! Increasing the cytotoxicity/toxic nature of your substrate will help a lot. Check for sulfo, sulphonamides, nitro, amine, etc. in a set pharmacophoric pattern, which can be deduced from know anti-cancers, especially the synthetic ones, methotrexate is a case in point!
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A performance task? A standardized test? Or some other means? Why?
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A question that needs more thought
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I want to start from phenol to synthesize this compound, but I dont know about the detailed mechanisms and conditions.
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Dear Jialiang,
many thanks for sharing this very interesting technical question with other RG members. I did a SciFinder search for this compound and found that it is not known from the previous chemical literature. However, the analogous compound is known in which the ethyl group in para-position of the phenyl ring on the left side is replaced by a methyl group. This compound has been reported in the following article:
Chemoselectivity in the Cu-catalyzed O-arylation of phenols and aliphatic alcohols
Fortunately this paper has been posted by the authors a public full text on RG. Thus you can freely download it as pdf file and print it out if required. The synthetic route is outlined in the attached reaction equation. You just need to replace the starting material 4-iodotoluene by 4-iodoethylbenzene.
Good luck with your reserach work and best wishes, Frank Edelmann
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Dear All
Our publication house “M/s Har Krishan Bhalla & Sons” has been actively engaged for the promotion and utilization of essential oil bearing plants, and sharing the international research experiences in the field in form of a international peer reviewed Journal subscribed in Worldwide, Journal of Essential Oil Bearing Plants (JEOBP, <www.jeobp.com>) since 1998 aiming to benefit to all who have interest in essential oil-bearing plants.
Now, it has been planned to bring about a new Journal Entitled “Analytical Chemistry Letters” under above mention publication house.
Analytical Chemistry Letters is a peer reviewed international journal which provides rapid communication in all areas of Analytical Chemistry. Six issues per year are proposed and the first issue is planned to publish in January 2011. The Journal will also available online.
The journal publishes original research articles, short communications as well as review articles in all relevant areas of analytical chemistry which includes modern analytical and bioanalytical, Analytical Chemistry with multidisciplinary approach, Mass Spectrometry, Separations, Spectroscopy, Biological and Clinical sciences, Genomics and Proteomics, Medicinal Chemistry, Pharmaceutical Science, Pharmacology, Pharmacy, Natural Product Chemistry, Organic Chemistry, Food Science, Forensic Science, Environmental chemistry / analysis, Electrochemistry and Instrumentation.
We invite you please be a part of first issue and first volume of said Journal and send us 1-2 good articles for publication. Please send your article at the address given below, you can send your article by E-mail. For this the publication house shall be highly thankful to you.
Dr M K Verma
Managing Editor
Analytical Chemistry Letters
Instrumentation Division
Indian Institute of Integrative Medicine, Canal Road, Jammu-180001 (J & K) INDIA
+91 9469502270
Thank you very much. I look forward to hearing from you.
Arvinder Singh Bhalla
For “Har Krishan Bhalla and Sons
7/1/2C, Prem Nagar
Dehradun – 248007, India
+91 9219506760
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what is the IF for this journal?
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I need to know that after dissolved EDTA in suitable solvent e.g. water, isopropanol etc.. what are the ionic species will form and how to confirm those ionic species presence using which characterizations? any references regarding EDTA dissolving reaction chemistry will be helpful. Thank you.
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Dear Umesh Nakate, dissolution is a physical process, which means one can not expect a chemical reaction to occurs. EDTA dissolution is pH dependent, because COOH groups are ionizable only at pH's higher than 2.24. the ionizable groups are behind the complexation interactions with metals for exemple. Please check the following for more details. My Regards
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I have read few articles (mostly based on simulations) that show metal nanoparticles bond with graphene or graphene oxide. However, I am thinking about how can metal (i.e. 0 oxidative state which is already in the lowest energy form chemical bonds with graphene (with no functional groups) or graphene oxide (has functional groups). I personally believe that metal nanoparticles are mostly adsorbed (Vanderwall forces) and no chemical bonding can occur. Please let me know your thoughts.
regards
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As XPS/ESCA shows the surface (top 10 - 15 atomic layers) of metals is not in the 0 oxidation state. Oxygen in the atmosphere conspires to have the metal in a higher oxidation state on the surface. In the late 1970’s we showed that even gold on silica matrix was in the +3 oxidation state. Zerovalent elements could only be revealed by Ar ion etching of the top layers. Silver is probably the best example.
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  1. Product is achieved using 1:1.
  2. Oil route is used instead of methyl ester or FA.
  3. Reaction is conducted under ambient pressure throughout.
  4. Our color test is consistently below 300 alpha but we have received enquires on whether we can make Alpha 120 requirement?
  5. Kindly please advise what can be done to achieve this? Thanks.
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Interesting study. Curious to know. Many thanks for sharing
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Hey
I need the free amine of Cystamine for my next reaction step but Cystamine is only available as a HCl salt.
i cant find any procedures/instructions on how to release the free base.
I tried dissolving it in 2M and 10M NaOH solution and extract it with chloroform and then evaporate the Chloroform on the rotavap – did not work
I also added NaCl to the aqu phase to saturate it – also didnt work.
anyone who worked with Cystamine or Cysteamine before and has a clue on how to Free the base?
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Hello Sabrina,
many thanks for sharing this very interesting technical question with the RG community. First of all, let's recall the difference between cysteamine and cystamine in order to avoid any confusion. Cysteamine is the simple compound 2-aminoethanethiol or 2-mercaptoethylamine, H2NCH2CH2SH, while cystamine is it's oxidation product, namely the disulfide derivative H2NCH2CH2S–SCH2CH2NH2. Pure cysteamine is a colorless, crystalline, and hygroscopic solid with an unpleasant, mercaptane-like odor. Due to its high solubility in water, free cysteamine is very difficult to isolate. Thus it is not really surprising that your first attempts to isolate it failed. What makes the situation even more complicated is the fact that the free cysteamine base is extremely sensitive to oxidation. Auto-oxidation in the presence moisture, light or heat leads to easy formation of the disulfide-bridged dimer cystamine.
My personal advice to overcome this problem would be to stay away from working in aqueous solution. To the best of my knowledge, cysteamine hydrochloride is soluble in methanol. Thus you can prepare a solution of your cysteamine hydrochloride in methanol (or ethanol) and combine it with a solution of 1 equivalent of KOH in methanol or ethanol. This should lead to quantitative precipitation of KCl, while in solution you have the cysteamine free base. Then separate the KCl by filtration and carefully evaporate the methanol (or ethanol) under vacuum using a "Wasserstrahlpumpe". This should leave behind the free cysteamine base as a solid or oil. Ideally, the entire reaction should be carried out under nitrogen using e.g. a Schlenk line (I assume that Schlenk apparatuses are still available in the labs of Professor Heinicke 😎) in order to avoid oxidation to the disulfide cystamine. The reaction should work even if cysteamine hydrochloride is not completely soluble in methanol or ethanol. It will dissolve during the course of the reaction, because the driving force in the insolubility of potassium chloride (KCl).
Alternatively you might consider if your next step could be done without isoplation of the free cysteamine free base, i.e. if it can be produced in situ and then allowed to react with the next reagent wthout isolation.
I hope this helps. Good luck with your experinents and best wishes, Frank Edelmann
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Dear to whom it may concern,
I wonder whether benzopyrylium ion is permanently or temporarily positively charged because I would like to convert its positive charge to its neutral form.
Would you mind if you may give me some suggestions in this case?
Best regards,
Khoa.
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I agree with Miguel that a ring-opening or destruction can be used to obtain benzopyran or an alternative.
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I see that silver mostly has a coordination number of two, and have seen to complex with two mono-dentates. Can Ag+ form complexes with di or tri or any polydentates ligands?
What kind of complex can Ag from with O- ? (when conditions are such that Ag2O does not form)
regards
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Hello Deepak,
this is in fact a very interesting technical question (or better two questions). For the first part of your question (Can Ag+ form complexes with di or tri or any polydentates ligands?) the answer is clearly YES. This is easily possible when the ligands are of the so-called tripod-type. The most prominent examples of these ligands are the tris(pyrazolyl)borate anions. The are also ferquently called scorpionate ligands. The tris(pyrazolyl)borate ligands and their coordination chemistry were developed by the Ukrainian-born chemist Swiatoslaw Trofimenko (1931–2007) in the mis 1960's and are still highly popular in coordination chemistry. The potassium salts ofc these ligands are easily prepared from KBH4 and various pyrazoles in a melt reaction. The resulting tris(pyrazolyl)borate anions for stable complexes with almost every metallic element in the Period Table including silver. Due to their special tripod-like geometry the scorpionate ligands are almost always tridentate. Thus with Ag+ they form tetracoordinate complexes. For a good overview of scorpionate complexes of copper, silver, and gold please have a look at the following useful review article:
Trispyrazolylborate coinage metals complexes: Structural features and catalytic transformations
Unfortunately this paper has not been posted as public full text on RG. However, two of the authors have RG profiles. Thus you can easily request the full text of this review directly from one of the authors via RG.
Good luck with your research work and best wishes, Frank Edelmann
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Kindly let us know the difference between white PAF and grey PAF. Will it cause any difference in the application?
Does these two types of PAF are used for separate applications?
Apart from chemistry, what is the difference in Super grade, grade I and grade II based on its applications
Which PAF is used for which specific application.
Thanks and regards
Pallavi Deshmukh
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Dear Dr. Pallavi Deshmukh thank you for your kind response and explanation. First of all this case shows that the use of ambiguous abbreviations can cause quite a bit of confusion. At least now it is clear what you mean. To my knowledge cryolite (Na3AlF6) and potassium cryolite (K3AlF6) are often contaminated with calcium and iron. The iron can for example be present in the form of siderite, FeCO3, which can cause yellow, brown, or even black colorations. Thus the main differences between white and gray potassium cryolite is purity. The white version is the purest material and therefore more expensive than the gray one. For a short explanation about the differences between the two please have a look at the following potentially useful link:
However, the explanation of the origin of the different colors given here is rather ridiculous (Citation: "The difference between the gray and white of potassium cryolite is actually the difference of a color."). Thus the article should be read with some care. However, the link provides a useful statement about the different uses of the two forms of potassium cryolite (gray: aluminum alloy additives and fluxes; white: grinding wheels, soldering fluxes and related high-end applications.
I hope you will find this information useful. Good luck with your work and best wishes, Frank Edelmann
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I am looking for a software that can predict the chemical reactions that will occur when I mix certain substances. For Example: Na+Cl --> NaCl.
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Some software of quantum mechanics such as Gaussian, Hyperchem, Material Studio, Gamess, and so on could support you to solve well it. Have a good day!!!
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I was preparing a phosphate buffer and adjusting its pH to 7.2 from 9.0 by adding monobasic phosphate. In the beginning, it started to decrease fast but then, it went slowly (it was about pH=7.6). Even though I added too much monobasic solution, its pH was not increased easily. Then, it went to pH=7.3 easily but it stopped at pH=7.3 again. I wonder why it happened. I know it is related to its titration and the titration graph is fine to understand but I need a comprehensive explanation for it.
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Dear all, one point should be considered, buffers in the alkaline part of the pH are unstable because of the ambiant CO2 (having acid character), so better to work under an inert atmosphere. My Regards
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We have small molecules, measured the critical micellar concentration. we getting keep negative value. it is a bit surprising. if anyone can explain the reason with support of literature will be helpful for us to come over the issue.
Thank you
Raj Kumar
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This can be a consequence of instruments errors or inaccurate use of mathematical equations if the extrapolation method is used to find a solution.
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Respected Sir/Madam,
I've attached a picture of manually drawn organic compound using "Pubchem Sketcher". I was planning to synthesis this molecule using synthetic chemistry protocols.
Considering me as a fresher to synthetic organic chemistry, I'd like to learn more about the following questions.
1. What are all the different synthetic routes/steps that could be used to synthesis this compound?
2. How do I find the chemicals list, the steps involved, and the reaction environment required for this compound synthesis?
3. What are all the computational tools to predict the organic synthesis pathways?
If organic synthesis protocols for this substructure is available, please share them for references.
Thanking you
Hari Prasath Nagaiah,
Research Scholar,
Contact: +91-6382704953.
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Dear Hari,
many thanks for sharing this very interesting technical question with the RG community. We have 40+ years of experience in inorganic and organometallic chemistry. Thus I'm not a proven expert in multi-step organic synthesis, but for our organometallic research we synthesized numerous organic ligands. So I would just like to add a few personal comments in addition to the very valuable expert answers provided by Corentin Lefebvre. I did a quick SciFinder search and found that this molecule has never been reported in the previous literature. When you ask "What are all the different synthetic routes/steps that could be used to synthesis this compound?" my impression is that the answer can perhaps be found in the course of a Master or PhD thesis, but not within an answer on RG. However, in my personal opinion the main question is "Will this compound have any useful applications which justify the efforts of synthesizing it?". If not, it is perhaps not worth spending months to develop a suitable synthesis.
As for the possible purification, it is clear to me that the compound will be a solid, so that recrystallization will be the purification method of choice. Since it is a carboxylic acid, chances are that it could also be dissolved in aqueous NaOH and then precipitated again by adding hydrochloric aid.
Good luck with your research and best wishes, Frank Edelmann
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Interested in knowing molecules with two or more sulfonic/phosphonic acid groups without a common endpoint (excluding phytic acid) and are available from natural resources or utmost commercially available.
Any relevant reading suggestions are also much appreciated. Thanks.
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Dear Nagapradeep N. that's a really interesting technical question. As an inorganic chemist I'm certainly not a proven expert in this field. In fact, without running a detailed internet search, no such compound immediately come to my mind (at least no naturally occurring ones). For a very good overview on the chemistry of organic phosphonates (including bis- and tris-phosphonates) please have a look at the following useful review article:
Phosphonic acid: Preparation and applications
This article is freely available as publiic full text on RG.
The situation looks much brighter when it comes to commercially available compounds of this type. For example, please check benzene-1,3,5-tris(phosphonic acid) and benzene-1,3,5-tris(sulfonic acid).
Good luck with your research!
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Please help me on how to synthesize low molecular weight N-methylol melamin resin that can penetrate the wood cell wall.
and what should be done to reduce formaldehyde emissions?
Thank you for your time.
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Dear Maryam Haseli, the question is a bit unclear, melamine is hexa-functional, methylolation is a function of the ratio melamine/HCHO, so may be you have to reduce the amount of formaldehyde. The attached study is concerned by HCHO low emission. My Regards
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Research chemists continue in their slow uptake of preprints. I've lately suggested one key reason for this unique behaviour of scholars in the basic sciences in two OA studies, one published by Publications:
and another by Insights:
What is your opinion on the origin of this delay? Has your team recently embraced preprint publishing? What are your favorite preprint repositories?
Thank you in advance for your insight.
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Dear Mario, this is certainly an important technical question which will be of broad interest to many RG members. When you say "Research chemists continue in their slow uptake of preprints" I can only agree with you from my personal experience. We have 40+ years of experience in chemical publishing, and during this long time we never ever posted a preprint on a preprint server. The reason? I may be old-fashioned, but personally I'm strictly against any form of preprints. I simply see no benefits in them, but only potential disadvantages. We always published our research work in international, peer-reviwed journals. What would have been the benefit of publicly posting an unreviewed manuscript? What if the manuscript is later rejected? What if someone else is "too interested" in our results and copies them? So why not wait until the peer-reviewed manuscript is published online by the journal? You can always use the waiting time for doing new research, writing the next manuscript, or working on a review article. In any case, I do not plan to post any preprints during the rest of my scientific life.
Good luck with your work and best wishes, Frank Edelmann
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Hello everyone,
I have a serious problem with coating the Pd/C catalyst uniformly on the glassy carbon.
I prepared the Pd/C ink by adding 20 mg of Pd/C into 9 mL of DI water. Then I sonicated it for 10 mins. I added 1 mL of IPA into the mixture and sonicated for another 10mins. I pipetted 5 uL of the ink on the center of glassy carbon (Diameter=3mm) and dried it in the air. To avoid any dusk from the air, I used a biker to cover the glass carbon. But I can't get a uniform layer of Pd/C catalyst on glassy carbon. Here is the picture of the Pd/C film. Can anyone help me with this problem?
Thanks,
Jay
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Palladium nanoparticles supported on carbon black powder as an
effective anodic catalyst for application in a direct glucose
alkaline fuel cell
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I have to use a variety of chemicals to identify and separate out the different red pigments within certain species of crabs' eyes, one of which it is suggested to used acidified methanol for ommochrome pigments. However we do not have any premade in the labs and they have told me to make some myself and i have no clue what the best method (or acid) to use for this is. There are some papers that say to use hydrochloric acid and some that say to use sulfuric acid.
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I think that there are researches in this field that you can get from searching on scientific sites interested in this field.
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Please help me on how to synthesize low molecular weight phenol formaldehyde resin that can penetrate the wood cell wall.
Thank you for your time.
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I think the article in attached may help you understand the process you are asking for.
Best wishes,
Sabri
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In the (electro-) conducting materials, as I know, there is an energy gap between the valence band (VB) and the conduction band (CB) that can be brought to or near-to the Fermi level by doping (p-type or n-type dopant).
But ( My question is ), If I want to design a (semi- or super-) conductor's materials (inorganic or polymeric) , Which properties would I look for? and, also, Which characterizations would I consider for the properties' investigations? What are the requirements for the materials' property (with regard to its band structure) to achieve the considered structure-property relationships (or requirements ) for the preparation of the conducting materials?
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Indeed Dear Ahmed MS Dawelbeit it is a very interesting and subtle question, refer to it as a localization phenomenon is one way since electrons can be seen as wave packets that can be or not well defined within the structure (metal, either metallic polimer).
In general, we have a kinetic criterium with three well-defined regions, the product "l . kF", since we understand localization as the absence of diffusion of any kind of waves in a disordered medium.
Please check for the case of metallic polymers, the following reference:
Alan J. Heeger, 2003, The Critical Regime of the Metal-Insulator Transition in Conducting Polymers: Experimental Studies. Condensation and Coherence in Condensed Matter, pp. 30-35
it is very instructive
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Dear RG Academics who Travel,
This is an important topic because many academics relish going to desirable places for conferences. My husband and I used to travel to scientific conferences but so much red tape is involved he and I are glad to attend mostly on video conferencing technologies (yes, like Zoom and others whose names I don't know. No intent to favor one or the other technology company)
It is good to remember that social bragging rights do not equal additions to knowledge (i.e., what exotic place one has traveled lately.). Yet, local economies are helped by all kinds of conferences and the money that they bring.
There are costs and benefits either way, so please share your ideas about continuing in-person conferences when there is little we cannot do via remote presentation, informal conferring and virtual "hallway" chatter.
Look look forward to your ideas.
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In the past traveling abroad was a strong motivation for scholars to attend to the international conferences. In fact, they could be familiar with other scholars from all around the world while it was amazing travel in terms of tourism. However, now, by pandemic restrictions and dramatic increasing in number of conferences also the video conference facilities, travel abroad for attending in conferences is not justified overall.
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If there is a slight shift position of the functional group or peak intensity after the introduction of a Li+ source salt, what is the possible and reasonable chemistry? Please share if there are any reliable references regarding functional polymers and Li+ solvation chemistry. Thank you!
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Dear Ljalem Hadush Abrha this is a very good question which is of significant importance in lithium battery research. In addition to the expert answer provided by Arnab Mukherjee I would like to suggest to you a few relevant literature references about this topic. For example, in the following study FTIR spectroscopy has been successfully employed to characterize Li-salt – polymer interactions:
Lithium Salt Dissociation in Diblock Copolymer Electrolyte Using Fourier Transform Infrared Spectroscopy
(see attached pdf file)
Please also have a look at the following interesting article:
Solvation and Dynamics of Lithium Ions in Carbonate-Based Electrolytes During Cycling Followed by Operando Infrared Spectroscopy: The Example of NiSb 2 , a Typical Negative Conversion-Type Electrode Material for Lithium Batteries
This paper has been posted by the authors as public full text on RG, so that you can freely download it as pdf file.
Yet another relevant article about this topic is the following:
The Effect of Solvation Shell Structure and Composition on Ion Pair Formation: The Case Study of LiTDI in Organic Carbonates
(see attachment)
I hope this helps. Good luck with your work and best wishes, Frank Edelmann
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I have obtained a strange result with electrocoagulation of a dye using aluminum electrode. Instead of having a decrease of removal percentage, I see that the percentage increases with the concentration of dye after it remains constant.
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This is may be related to the fact that, as the concentration of dye increases, the adsorption capacity of metallic hydroxide flocs becomes exhausted early. Besides, increasing dye concentration leads to increase association of dye molecules, this decreases the adsorb ability of the dye molecules on M(OH)n because of the unavailability of the polar functional groups which are consumed in dye association, or probably because the dye concentrations becomes too high in comparison to the amount of flocs generated.
However, the cathode passivation prevents the electron transfer between anode and cathode and hinders the metal hydroxide formation which negatively impacts the performance of the process.
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Hi everyone! I have a question for my farm compost.
So i just do my research and try to look for a compost with :
around 3.5% of Total N Content,
around 5% for my P2O5 content, and
around 1.5% for my K2O content.
And i just wonder, if i just combine :
Cocoa shell meal with 2.5% N, 1% P2O5, and 2.5% of K2O,
with
Worm casting that has 1.5% N, 2.5% P2O5, and 1.3% K2O,
Would it turns my compost into 4% N, 3.5% P2O5, and 5% K2O just like that?
i'm so confused as i'm not really good in both chemistry :D (as a geophysics engineer, chemistry is such a hard subject for me).
Thanks!
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Dear Muhammad Ardhya Wirananggapati,
I do not think that you will get the proportion you intend. It is not a nutrient balance study you are doing. What is lost during your process? What is the process? There I am sure you will not get what you proposed. It is better to look at it at different proportions and then you will reach some rates than this one. That is why combination studies are recommended!
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Its a colloidal solution of nano materials and AlF3 forms during the reaction and its still exist in the sample even after water washings.
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Thanks for the information.
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I have tried dissolving sodium oxalate in water and I am currently trying oxalic acid in NaOH however this does not seem to be working either. it wont dissolve and I cant find the answer on the internet anywhere. Someone please help
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Dear Lee McMahon P.S. If it's the oxalate anion which is important for your work, you might consider using potassium oxalate instead of sodium oxalate. The molar mass of potassium oxalate is 184,23 g·mol−1 (as the monohydrate). In contrast to the sodium salt, potassium oxalate is highly soluble in water: 360 g·l−1 at 20 °C (anhydrous salt). Thus in this case it should be easily possible to prepare 2.5 liter of a 1 M solution. You would need to weigh out 460.58 gram of potassium oxalate and fill this up with deionized water to 2.5 liter. Do not use tap water because you will then get a precipitate of calcium oxalate!
(For some reason the English Wikipedia entry does not list the solubility.)
Good luck with your work and best wishes, Frank Edelmann
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Hello everyone,
I need to choose a topic on design and analysis of experiment as a project. The project consists of planning, designing, conducting and analyzing an experiment, using appropriate principles and software package of design and analysis of experiments. Could you please recommend me an article or any reliable resources for the project? It must encompass 2 nuisance factors and topics such as Randomized blocks, factorial designs, 2k design and NOT RSM or CCD.
Best wishes
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I suggest you the followng book by D. Montgomery:
Montgomery, Douglas (2013). Design and analysis of experiments (8th ed.). Hoboken, NJ: John Wiley & Sons, Inc. ISBN 9781118146927
Best regards,
Ebrahim
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After the execution of the test of PDP ( Potentiodynamic Polarization) and the plot of Tafel curves, we need to extract to parameters from the plots in order to determine the corrosion inhibition efficiency.
We need Icorr ( current density) to determine the IE ( Inhibition Efficacy)
But, concerning βc and βa, where we can use them? Can we calculate something from them? Does the change of them from concentration to concentration of inhibitor say something?
PS. I'm doing only corrosion inhibition of Mild Steel in HCl, I'm using simple equivalent circuit containing Rs ( Solution resistance), Rct( charge transfer resistance), and CPE ( phase constant element).
Any contribution to this question will be appreciated.
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Dear Dr. Alexander Sinko ,
by changing the inhibitor concentration for the different PDP tests, a non-significant change in the numerical values of βa and βc reveals that there is no alteration of the mechanism of inhibition of the anodic and cathodic corrosion reactions.
For more details, I suggest to have a look at the following, interesting papers:
-Effect of Intensifier Additives on the Performance of Butanolic Extract of Date Palm Leaves against the Corrosion of API 5L X60 Carbon Steel in 15 wt.% HCl Solution
Saviour A. Umoren, Moses M. Solomon, Ime B. Obot and Rami K. Suleiman
Sustainability 2021, 13, 556
-Corrosion Inhibition of Mild Steel with Tolyltriazole
H. E. Fathabadi, M. Ghorbani, H. Mokarami Ghartavol
Materials Research. 2021; 24(4): e20200395
-Niclosamide and dichlorphenamide: new and effective corrosion inhibitors for carbon steel in 1M HCl solution
Fouda, A.S., El-Desoky, H.S., Abdel-Galeil, M.A. et al.
SN Appl. Sci. 3, 287 (2021)
-Electrochemical studies of novel corrosion inhibitor for mild steel in 1 M hydrochloric acid
Ahmed A. Al-Amiery, Mohammed H. Othman Ahmed, Thamer Adnan Abdullah, Tayser Sumer Gaaz, Abdul Amir H.Kadhum
Results in Physics, Volume 9, Pages 978-981 (2018)
My best regards, Pierluigi Traverso.
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Hello evreybody
When we used CTAB as a capping agent in reducing 4-nitrophenol by Ag NPs, Why CTAB is not good as much as SDS with the same reaction? What is the main reason with it?
#chemistry
#nanoparticles
#silver_nanoparticles
#CTAB
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I think in case SDS the surfactant charge on Ag nanoparticles play the crucial binding role which helps in reduction of 4-nitrophenol by Ag nanoparticles as in CTAB NH4+ Cationic part is much larger compared to Na+ in SDS which corresponds to greater charge to suface ratio for sds which favours the 4 nitrophenol reduction by SDS/Ag nanoparticles.
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In what case would a reaction rate always show direct relation with activation energy or would it always be an inverse relation? Is it a indirect relation, inverse relation or both case can hold? (Please provide supporting resource, thank you).
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Toyese Oyegoke when we are talking about your question and particularly the catalyst which always lowers the energy of the transition state for the reaction - in this case any reaction you can assume.The difference between the transition state energy and the other part that is the reactant energy is the main ACTIVATION ENERGY and this is very important to understand, Lowering of this energy which means lowering of transition state energy also ensures and lowers the activation energy for sure
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I would like to know which of these reactors is expected to record the highest conversion for CSTR and batch reactor when both reactors are assumed to have a similar volume, geometry, operating condition, and stirring rate (if possible do provide supporting resource/reference).
Thank you as you share your experience.
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Toyese Oyegoke alrady the expert comments from Dr Prem Baboo has nailed it and wow loved his answers and the explanation as well thankyou Prem Baboo and being from the same industry it is always good to find like minded people
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Sodium decahydrate is Na2CO3.10H2O which is obtained by dissolving sodium carbonate in water and then crystallizing it. So can be consider it as a mixture (i.e. an impure substance) or is it a compound (pure substance)?
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IT IS a compound
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I need to do MD simulation for positrons (antiparticles of electrons). Is it possible to do MD for positrons in the liquid medium?
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If you wanted to do that, you would have to assume that the positron has a classical trajectory which is of course a severe deviation from the fundamentals of quantum mechanics unless you want to work within the framework of the fringe De Broglie-Bohm theory (https://en.wikipedia.org/wiki/De_Broglie%E2%80%93Bohm_theory).
If we ignore this major caveat for a moment, you can in principle treat a positron like a "very light cation" with a mass of 5.5E-4u and calculate an "MD trajectory" with the interactions you get along the way; former colleagues of mine tried that for electrons when they wanted to estimate the height of repulsive coulomb barriers in multianions, but the result was not particularly satisfying, as far as I've been told.
An additional problem would of course be the neglegt of annihilation probabilites in that process.
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I am doing my thesis, this is about the design of a theoretical plant to obtain furfural. I need this book to know first hand: what are the by-products during the chemical reaction and how to calculate them? all this for a balance of matter. Excuse my english, thanks
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Dear Carlos Villacreses,
The above mentioned book is available. Kindly find the link below.
If you find any problem let me know I had downloaded the book.
Good Luck for your Thesis !
Regards,
Yawar
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Greetings
One of the most major problems of writing an undergraduate article is the lack of access to a laboratory and a professor to check the accuracy of article information in the laboratory.
For example, at my university, only postgraduate, PhD and postdoctoral students are allowed to work in the laboratory. What should an undergraduate student do if he or she wants to write an article and extract the information needed for his or her paper from the lab?
Undergraduate students do not have access to professors and laboratories to verify their ideas, what should they do to write an article?
Can he write another type of article that is published in a valid journal but does not require laboratory information? Or can he collaborate with a foreign professor to write an article?
What is the solution to the problem?
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Dear Pejman Rahmani Nejad many thanks for asking this very important technical question, which is certainly of broad general interest to many RG members. I'm afraid that my answer is not what you want to hear, but of course you are absolutely free to ignore it. My initial thought was: Why should an undergraduate student write a scientific article? In my personal opinion (which might be somewhat old-fashioned) the main job of an undergraduate student is to attend lectures, courses, and seminars, collect basic knowledge and pass exams. Especially in your discipline, chemistry, you can only write a scientific article if you have new results to report, and new results can normally be achieved only in the lab (if it is not theoretical chemistry). Moreover, you need to have a supervisor / senior scientist / principal investigator who conceicves the research and acts as corresponding author. Writing of a review article is also not a good idea at the undergraduate stage, as you must be a proven expert in the field covered by the review. Thus, in the end, why don't you just be patient and wait until you worked on an own research project and have sufficient new results to publish?
Good luck and best wishes, Frank Edelmann
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Interested in using commercially available heterocyclic/non-heterocyclic aromatic S-sources for making metallic sulfides under pyrolytic conditions.
Any relevant reading suggestions are also much appreciated. Thanks.
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Dear Nagapradeep N. this is a very interesting technical question. In this context it might be interesting for you to now that thiophenol, C6H5SH, has been reported to be extremely stable to thermal decomposition. According to the article cited below, pyrolysis of thiophenol (= benzene thiol) does not start below 500°C:
Chapter 12 Pyrolysis of Thiols and Sulfides
The chapter has not been posted as public full text on RG, but the Abstract already contains essential information.
Please also have a look at the following potentially useful patent, in which the synthesis of metal sulfide nanocrystals using thiols as precursors has been claimed:
Method for producing metal sulfide nanocrystal using thiol compound as sulfur precursor
Good luck with your research and please stay safe and healthy!
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Dear community,
I have been preparing MoS2 through a hydrothermal process by combining thiourea and ammonium molybdate with 2.28 g and 1.2 grams, respectively, in a 35ml DI water and place it in 70 ml teflon autoclaves, at the end I would get 1g of MoS2 powder. Now, the issue is that I am forced to switch for thioacetamide as sulfur source, so I started with the same proportions as the thiourea (2.28g) but it appears that it is too much I get a very thick slurry in the autoclave instead of just light slurry that I can wash. So,any recommendations of proportions and weights that I can use to get similar results as the thiourea one?
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Dear Abdullah Mahmoud Solayman thanks for posting this interesting technical question. It would be interesting to know who "forced you to switch for thioacetamide as sulfur source"? In any case, Alan F Rawle is absolutely right in that the molar masses of thiourea and thioacetamide are nearly the same, so that the calculated amount of thioacetamide would be 2.25 g if you want to employ the same molar amount. Did you follow literature references in your experiments? I think you should read some relevant literature first before you continue with the thioacetamide reactions. For example, please note that the authors of the following article also used both thiourea and thioacetamide for the preparation of MoS2, but in the case of thioacetamide they added a certain amount of hydrochloric acid. So it's not self-evident that both reactions proceed under the same conditions.
Hydrothermal assisted morphology designed MoS2 material as alternative cathode catalyst for PEM electrolyser application
This paper is freely availabe as public full text (see attached pdf file).
In the following relevant article the pH of the reaction mixture (sodium molybdate and thioacetamide) was adjusted to 1.0 by adding hydrochloric or sulfuric acid:
CONTROLLABLE PREPARATION OF NANO MOLYBDENUM DISULFIDE BY HYDROTHERMAL METHOD
(also attached)
Good luck with your research and best wishes!
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Hi,
Even though Artemis gives an error bar on the EXAFS fitting but it assumes the value to be zero at certain R values.
In the case of data with some experimental noise, the error bar needs to be corrected, weighted by the square root of the reduced chi-squared value, taking into account the experimental noise for each R-space spectrum from 15 to 25 Å, as described in
How do calculate the uncertainties in the coordination number when EXAFS is fitted using Artemis?
Thanks in advance
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Thanks, Gerhard Martens it was indeed insightful
I have one more case where relatively good data (up to k=14) gives the following fitting (see attached).
it still show a huge error bar? can it be solved somehow?
Thanking you,
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Hello, I'm an early career PhD student. When people ask me questions e.g. In conference or lab meeting, even when I know the answer my mind tends to go blank and I say I don't know just to get out of the situation. I used to be good at answering questions and taking time to think and answer , especially during my bachelors degree. As time was gone by I feel I have gotten worse mainly because I am afraid the answer will be ridiculous and made fun of as I have reached a very advanced level where everyone knows what they are talking about. After all these years sometimes I get tired of science in general and have no motivation to read up on my project , so sometimes I genuinely don't know the answers which makes things worse . I used to have a lot of passion which is what put me on this path, but at the moment I'm tired of science which is making it hard to answer peoples questions and i think people are starting to notice. My answers are generally non specific and waffley, and I was wondering if anyone has tips to overcome these problems. I am interested in my project and deep down I love science and wish I could do better and go back to how I used to be and express my answers logically and what is expected at this level. This is especially important for my thesis defense, I need help and tips please on how others process these questions and defend their work. This problem has also started to overflow into my writing where I can't think properly or focus with the overwhelming amount of information.
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Also to defeat fear, you must program your mind. Mind preparation is a strategy to defeat fear.Tell yourself you can do it. Don't limit yourself, you will be amaze what you can do when you program your mind.
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We are trying to prepare liquid MMN culture medium (Marx, 1949), but we have run into a precipitate problem. We observe the precipitate for the first time after autoclaving. However, when repeating the procedure for the preparation of the medium, we observed that an almost negligible precipitate was already produced after adding the FeCl3. We see that the water turns whitish paying enough attention.
Below I detail the concentration and the order of addition of each component in the medium:
  • CaCl2 · 2H2O -> 66 mg / L
  • NaCl -> 25 mg / L
  • KH2PO4 -> 500 mg / L
  • (NH4)2HPO4 -> 250 mg / L
  • MgSO4 · 7H2O -> 150 mg / L
  • FeCl3 · 6H2O -> 19.992 mg / L
  • Thiamine HCl -> 100 μg / L
  • Malt extrac -> 3 g / L
  • Glucose -> 10 g / L
  • Agar -> 15 g / L
Could an Inorganic Chemist or someone who has prepared this medium before help us?
Thank you very much in advance.
Note: To date we have always prepared the MMN culture medium with agar and we had not observed any precipitate, perhaps because the agar prevented appreciation after autoclaving.
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This Question which interested me a lot, thank you very much
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When it comes to choosing a good journal, it has always been debated which one is more important? Impact factor (IF) or journal quartile (Q)?
I give an example, you have three following journals, which one would you choose?
1- IF: 1.3 & Q1
2- IF: 2.5 & Q2
3- IF: 3.9 & Q3
Please select one of the three journals above and give a reason for that.
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I extracted impact factor and quartile of all mathematics journals based on new report released by Clarivate 2021.
Please, click on the following link:
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C1s peak at 284.8 corresponding to Adventitious Carbon is a reference for the X-ray photoelectron spectroscopy (XPS. However, when using carbon-based support, say Vulcan carbon (rich in graphitic carbon), r-GO and GO for deposition of active catalyst.
The C1s peak in these cases will be dominated by sp2 carbons, not by Adventitious Carbon.
How to calibrate the XPS data in that case?
How to account for the charging problem?
Thanks in advance
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As Jurgen states, the vulcan carbon should have enough conductivity. If using a monochromatic XPS system then analyse without the charge neutraliser on and ensure the carbon is in contact with the spectrometer (e.g. pressed in to a metallic well on the sample bar), then you shouldn't have an issue. The sp2 carbon will be ~ 284.5 eV depending on how well your spectrometer is calibrated.
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Hello,
I synthesized alginate methacrylate and performed an NMR spectrum. I'm not an expert in organic chemistry and I would like to be sure how to calculate the degree of methacrylation.
Thank you very much for your help
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We can not calculate the degree of methacrylation by using NMR spectra. In this case, the role of NMR spectra only conform that the chemical reaction has occured or not through looking up the feature peak of chemical bonds (For example: C=O, C=C, and so on). If your samples exist the solid state, you can calulate the degree of methacrylation by using the increase level of dry mass and titration method of functional groups.
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What will be the expected impact factor of Chemistry of Flat Materials (FlatChem) ?
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For those still interested. According to the latest Impact factors list (released a few days ago, see enclosed file) is of “FlatChem”: 5.227
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I am working with a reagent that is prone to hydrolysis for my chemical reaction. For that reason, one of the procedures that I am following recommends the use of freeze-pump-thaw cycles to degass the solvent. However, can I just use an anhydrous solvent instead of going through this process? Forgive me if this is a very obvious question.
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Dear Samuel, thank you for asking this interesting technical question. If you are working with a moisture-sensitive compound and use carefully dried solvents, there is no real need to degass the solvent. However, always keep in mind that there is moisture present in the ambient air. Thus in this case it is advisable to work under exclusion of air (e.g. Schlenk line, dry-box etc,) right away. Good luck with your research!
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I am working on my research proposal on the topic, "physical proximity and technology-enhanced collaborative learning in Chemistry. And am going to use the topic matter and change, using CK-12 foundation.
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Thank you so much!
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I have a micro array membrane from abcam and i need to view the array in the Bio Rad chemi doc MP instrument. Is there any specific setting that needs to be followed for a membrane array or is it the same as viewing a western blot?
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Rajarajeshwari Thada when i see about the chemi doc instrument or the images of micro array membrane using chemi doc instrument then please do have a look at the link shared herewith and am sure this will be helpful as well
Chemidoc imaging system is also shown here with the attached link of PDF
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Hello, everyone!
I am using metal oxide/Graphene composite and electrospinning it using PVA/Water polymeric medium. When I deposit on the aluminum foil the surface is uniform with fewer flakes. I am speculating that this may be due to the polymer/solvent non-uniform evaporation from the surface due to annealing (450C for 2 hours). Can anyone suggest something from their experience about the annealing of metal oxide electrospun film for robust adhesion and uniform deposition? is these flakes normal? or do I need to change the polymer or solvent?
thanks in advance.
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This looks like it could come from the low wettability of the water on your substrate. You could measure the contact angle with your solution to make sure. In case this angle is effectively high you could try to do a plasma treatment of your substrate to increase wettability (if it can support it) but the best option would probably be to change the solvent.
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Several studies on combustion of bio diesel/petroleum fuel blends in IC engines and other power generation / combustion devices discussed extensively about the influence of fuel unsaturation on NOx emissions. A fundamental question arises on how we quantify fuel unsaturation?
I would like to start a discussion on the topic - How to quantify fuel unsaturation ? what would be an appropriate index to quantify unsaturation irrespective of the family of origin of fuels - like methyl esters, ether, alcohol , alkanes, alkenes, alkynes or aromatics or a weighted combination of aforementioned categories.
Our research group's take on this -
We have established a parameter - Degree of unsaturation that serves as a common platform across different fuel families (esters/alkanes/aromatics) to quantify the effects of fuel unsaturation, particularly with petroleum/bio-diesel blends. DOU can be evaluated based on the average molecular formula of the fuel alone without involving complex and expensive experimental procedures such as those involved in the measurement of iodine number and bromine number.
If interested, please follow the link to access the research work we have conducted at our laboratory to investigate the effect of fuel unsaturation on nitric oxide emissions.
Message me to get a copy of this article.
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There are also standard test method to determine the unsaturation of fuel and biofuel, including:
a. Iodine number, AOCS Cd 1-25 (for biodiesel)
b. Composision analysis, by GC (Generally we can use ASTM D6730 for gasoline, and 2D GCxGC for middle distilate fuel)
Regards,
Fathurrahman
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I use a vacuum desiccator to remove dissolved gas in a NaOCl solution (2.5wt%)
The vacuum pressure is about 2 kPa and I observed the solution start to boiling.
However, dissolved gas is still eluted after the NaOCl solution is stored in vacuum for about 1 week.
In general, dissolved gas in water is sufficiently removed in about two days.
In my opinion, I couldn't completely remove the dissolved gas due to a chemical reaction that I am not familiar with.
Why can't I remove dissolved gas in an NaOCl solution?
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It depends on what you wish to do. e.g. Add HCl, and Cl2 gas will evolve.
See if any oxgen scavenger can be used for removing it
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I have prepared natural fiber reinforced polyolefin composite for which methane emission has to be estimated once it lands to landfill after completing the service life. Is there any article which talks about this or any methodology to estimate the green house gas emission specially methane.
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Thanks all for your valuable inputs.
Prof. Hatsuo, its a short fiber reinforced polyolefin composite. it would be great if you can advise any standard ASTM/ISO or research article dealing such kind of problem.
For landfill, is it the anaerobic degradation that we should look for?
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the result of expression analysis by by two different chemistry taqmen and cyber results can be comparable used for the same research topic.
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In most cases, the result of expression analysis by two different chemistry taqmen and cyber results may be comparable but at first, the phylogenetic relationship between the target organisms needs to be checked. Thanks.
regards
Marzan
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I have prepared cerium oxide nanomaterials. I obtained the spindle-shaped morphology by agglomeration of a number of nanorods. What chemistry can be involved in the agglomeration of nanorods into spindle-shaped morphology.
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Dear Surjeet Chahal many thanks for your very interesting technical question. Spindle-shaped cerium oxide nanomaterials have been observed by other researchers before. In this context please have a look at the following potentially useful articles: