Chemical Bonding - Science topic
Chemistry as a core subject or as applied science cannot be understood without having a strong grasp on chemical bonding. From our head to toe, from kitchen to a super market. from a cart to a spaceship, there is compounds, molecules, free radicals, ions all in one way or other shows bonding. At the same no bonding is 100%, a covalent specie has ionic character and an ionic specie show covalent character. So lets explore the world of chemical bonding by sharing, contributing or transferring our knowledge
Questions related to Chemical Bonding
A variety of adsorption studies are being carried out globally. I want to know, if any molecule is adsorbed over the surface of any substrate will built-in electric field generation take place at the junction? The question needs to be divided further into two parts (i) when the molecule is adsorbed and it does not form any chemical bond with the substrate there is a charge difference at the interface and there should be the generation of a built-in electric field (ii) if there is any type of chemical bonding still the polarity difference is intact, shouldn't electric field be there ?
Please attach any literature that supports your answers.
Dear Researchers :
I have this question and I have an hypothesis:
Why Natural HDPE, when extruded at temperatures about 100 °C (around) it has a white (but pale white), and then when the polymer cools down it color turns between white an yellow.
I understand that this phenomenon it is a general case of all LLDPE, LDPE and HDPE , and in all fabrication processes : Extrusion, injection, molding, pressing, etc.
So this is fundamentally, a chemical characteristic of the material ...
It has to do with a change in the Oxygen concentration in the material ?
Thank you all in advance,
Best Regards !
The phenomenon of material interlocking
· Joint interface
Please share your thought.
Your opinion is highly appreciated
I'm currently looking at the rheological properties of the polymer Xanthan Gum. focusing on its dynamic viscosity to be more specific. I'm assessing the effects of pH (ranging from 3.6 to 5.6, 0.4 increment, total of 6 pH's) on the dynamic viscosity of xanthan gum solution (dissolving xanthan gum powder into acetic buffer with equal ionic strength, concentration is kept at 0.04%).
Firstly, my viscosity data collected shows that, as pH increases from 3.6 to 4.0 then 4.4, the viscosity increases; but as I bring up the pH from 4.4 to 4.8, 4.8 to 5.2, then lastly 5.2 to 5.6, the increasing viscosity trend plateaus and the increase in viscosity is less significant compared to the 3.6-4.4 jump. At this range, does pH has an effect on the viscosity of xanthan gum based on its molecular configuration? Though some sources states that xanthan gum's viscosity remains stable and unchanged within the range of pH 3-12 at a high concentration like 1% not 0.04%, yet some suggest pH still plays an effect, though I'm not sure how on the chemical and molecular aspect.
A possible conjecture I can think of is the xanthan gum's order-disorder and helix-coil transition is affected by protonation. In figure 2, it demonstrates how electrolytes affect the structure of the polymer; in figure 3, it shows how at a state of a helical rod and no longer a random coil, it is capable to hydrogen bonds among each other. Hence, I'm wondering of pH plays an effect on it's structural transition, such that the increased intermolecular forces at the form of a helical rod would make it more viscous in solution.
Here are the resources I have used so far:
Brunchi, CE., Bercea, M., Morariu, S. et al. Some properties of xanthan gum in aqueous solutions: effect of temperature and pH. J Polym Res 23, 123 (2016). https://doi.org/10.1007/s10965-016-1015-4
I want to remove thiol molecules on a gold substrate. After searching, I found couple of method described below;
1. NH4OH–H2O2–H2O solution aim is to initiate the oxidation of the thiol compound
2. Thermal desorption (above 200 ◦C)
3. Ultraviolet light and ozone (O3)
Do you have any experience about these methods. If your answer is yes, can you share your experience with us? Thank you for sharing and helping,
Is it possible to change or form new chemical bonding using frictional heating during high sliding operations?
Hello, I am doing a carbon surface modification with Gold nanoparticles.
from the FTIR below, I know the formation bond of NH3 and for COO , but I would like to know what is the range of thiol bond formation, is this FTIR good or not?
note that I know that the difference between the bare SPE and modified SPE is the increase of current which is measured by Potentiostat.
thanks in advance.
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)
My major is based on the experimental. I rare often go to get help from software.
I am looking for the software to simulate the possibility of chemical reaction between POLYMERS. The reaction was not reported yet in any paper. I tried to find somehow similar reaction between two polymers with similar functional groups. But, not successful. I tried to use MD simulation, but interaction parameters are completely unknown. Again, I tried to use the interaction parameters between two similar MOLECULES (and not polymers).
I am wondering if there any software to simulate the reaction properties including the possibility of the formation of the chemical bond, decomposition of the bond, equilibrium constant, the heat of reaction, is it equilibrium one or not, how the Temperature, pH, ionic strength, time …. Affect the reaction.
I don’t mind if the results come with some error since my synthesized polymer and my reaction not reported at all, although basically, it is very simple for the reaction between two functional groups. It is the reaction of –COOH with an amine (but both of them are a polymer).
It would be nice if I can design my polymers only with the 3-4 monomer (oligomer) and then try to see the results.
I don’t mind, I pay for software. The high cost is also OK. But, I am a Chemical Engineer, and my knowledge about chemistry is poor. I can get professional chemistry help.
Rajabzadeh k. Saeid, Associate Professor
I have stadium stairs made of concrete, and i need to pick an adhesive material that give a good bonding strength and can resist some environmental factors such as hot and cold weather without peeling off. ( ceramic- polymer composite).. I can،t wait to read your esteemed answers.
Currently trying to bond a PDMS layer to the nickel plate with a very thin thickness (0.25 mm). I have tried several adhesives (epoxy, instant adhesive etc.) however none of it seems to work. Meanwhile, I have already looking at but haven't tried the method of PDMS bonding to glass by simply applying pressure while putting it at a certain temperature (60 - 80 Celcius). Does anyone have any experience with this ? or will this PDMS to glass bonding method also work for nickel plates?
I think that urea-formaldehyde resin(UF) and melamine-formaldehyde resin(MF) or MUF resin have a physical bond with wood. Also, I think that phenol-formaldehyde resin and MDI are chemically and physically bonded with wood, but I would like to check if my thinking is wrong.
I use a metal powder as the filler to a thermoplastic polymer matrix. Therefore, I wonder if there are any changes such as the molecular weight distribution, occurring in the structure by adding the filler metal powder?
Is any way or method to seal agarose pad or channels fabricated agarose gel pad to glass slides as like we do plasma bonding with PDMS to glass slides?.
Understanding the presence of chemical bonding in a polymer is available using FTIR or Raman Spectroscopy.
Considering a chiral solid-polymer (fabricated mat); Is there anyone who can hint at finding out and plot dipole orientation?
Any help for a characterization technique to ascertain and analyze the dipole bond rotation by the quantity and/or quality is generous.
I did a oxygen plasma surface treatment of a polydimethysiloxan surface. i coated it with two different materials and the bonding improved significantly with one of the materials.
the other material wasnt affected at all by the plasma treatment.
Now i want to draw conclussion about the polymer that are used in this materials. Which kind of polymer bond with a oxygen plasma treated pdms surface?
I think the material with the improved bonding is a silane-terminated polymer, but i am not sure about it.
Please let me know if you got some knowledge about this topic or any hints for me
I would like to illustrate this question below.
I am studying the material, which has predominant covalent bonding at ambient conditions. Now I am changing (increasing) the temperature. Due to these changes in temperature, the predominant ionic bonding has been established now in my systems. In this present case, temperature-driven bonding transition (from covalent to ionic bonding) has been established in the material.
How do we characterize the above-mentioned bonding transition? What are the characterization techniques to understand this bonding transition?
I kindly request you to answer this question. Your answer will help my research work a lot.
I want to measure strength of polymer-to-metal adhesive bond. My final sample is produced in this way, first I insert metal into plastic injection mold and then inject plastic into mold by plastic injection machine. picture of final part is attached. now my question is that which standard is suitable for measuring strength of polymer- to-metal adhesive bond of this sample?
Many thanks in advance for any kind help
NBO analysis of a donor-acceptor interaction not showing any NBO associated with that particular interaction. Although there are no NBOs associated with the interaction we are interested in, is it still something else useful we may deduct from it. We are not interested in NBO charges.
I believe that in a particulate composite with elastic mismatch between the matrix (brittle) and the aggregate (ductile) the bond strength between the matrix and aggregate will have an impact on the overall elastic modulus of the overall composite. Would anyone be able to point me in the right direction please?
Is there any reference to explain the polymeric bonding mechanism of epoxy resin polymeric adhesives to carbon fiber reinforced polymer (CFRP) laminates or strips. I am a structural engineer and I would like to understand the chemistry aspect of this bonding process.
ABO3 perovskites show cubic structure at high temperatures where the
A-site cation is having 12 coordination with oxygen ions and
B-site cation is having 6 coordination with oxygen ions
But whereas in low temperature stable phase of ABO3 structures (particularly in rhombohedral sodium bismuth titanate)
What is the effective A-site cation coordination (6 or 9 or any other) in NBT?
Please give me brief answer with references.
Does anyone know about techniques used to study chemical bonding between protein(peptides) and vitamins after passing through artificial gut?
I have a a question regarding surface modification of SiO2 chip. The presumption is that vapors of trimethylsilanol (CH3)3SiOH bond with the original hydroxyl terminated surface of the chip and cause wettability issues, not unlike the manufacturing process of hydrophobic sand (Magic Sand). Could someone please advise how would we go about removing these methyl terminating groups from surface and restore the original hydrophilic hydroxyl group termination?Oxygen plasma did not seem to have an effect on improved wettability. Surface is Si₃N₄, SiO₂, aluminium pads.
Thank you for ideas.
I did Electrophoretic deposition of Ni-Graphene composite on stainless steel and carbon steel as a substrate, but the problem that i am facing is that chemical bonding of above mentioned with substrate is not so good and can be easily removed, need a suggestion what to do?
During experiment i used Graphene and Ni soloution instead of graphene oxide.
What does complexion stands for, and how complexion is formed or mechanism of complexion. what is its importance in adsorption? Is it any way related to cation exchange?
Is this curvature only related to the spatial arrangement of the links in their structure.
Does this spiral state have a fundamental effect on the function of this molecule?
In particular, does it make it easy to copy genes?
Or is it only helping to occupy this long string in a smaller volume?
I tried to heat (oxidise) the Fe powder at 500C and it got sintered (bonded) together. The bonding is so strong that its not easy to manually grind it to get back the iron oxide powder. XRD shows that all Fe transformed into Fe2O3 and Fe3O4. What is the reason of this bonding? and How to avoid this?
Please discuss if the calculation of bonding energy (metallic/ionic/any others kind of bond) between two atom of a crystal structure (cubic/tetragonal/monoclinic/any kind of crystalline structure) is possible using the Rietveld refinement of the XRD data and how?
For example, how to calculate the bonding energy between A-B atom of ABX3 structure using the refinement study of the XRD data after details investigation and which parameters should be considered?
Thanks in Advanced.
I have been thinking in organosilanes, but I am concerned if these binders will affect TiO2 photocatalytic properties. Although a physical deposition shows usually good adhesion, I am interested in creating a chemical bonding between the substrate and nanoparticles
Dear respected RG members,
I am doing Mulliken population analysis of Cobalt (Co) doped MgO lattice (rocksalt) using CASTEP code (ultrasoft pseudopotential). I found some strange data as follow:
for pure MgO
bond population (Mg-O) = - 0.73
for (3%) Doped MgO
bond population (Mg-O) = - 0.31
bond population (Co-O) = 0.42
Is the negative value of of Mg-O reliable?, since negative value indicate antibonding, small value close to zero indicate ionic bonding and large positive value (Co-O) indicate covalent bonding. As we know, MgO has a very strong ionic bond, therefore bond population (Mg-O) must be close to zero. All parameters that I used during optimization are correct. I also did the same calculation using ( norm-conserving ). The obtained data gave almost a good result as suggest by Segall et al. (Mg-O = 0.58) and (Co-O = 0.53).
Thanks in Advance
I want to bond PDMS on 3d-printed structure (from SLA 3d printer, Form 2). In fact, I don't know exact composition of resin of 3d printer, but I guess its main component is acrylate (maybe PEGDA).
How can I bond them? I've googled, and found that PDMS and PEGDA can be bonded with 3-(trimethoxysilyl) propyl methacrylate. If correct, with which process should I bond them with this chemical?
First, I grew the ZnO films on Si(111) by RF sputtering system and then I used the Ar ion bombard on the ZnO films surface. I would like to observed not only changes on surface morphology but the chemical bonding or defects(XPS) on the ZnO films surface at various stages of bombardment. Moreover, the Ar ion will strike the Zn and O atoms and reveals the defects or Zn(metallitic) terminated surface. So when I used the oxygen gas into the chamber and react with the surface after bombardment process it would change the surface state again.
What kind of interaction does the performance resins offers for a filled elastomer? Is there any chemical bonding or only a physical interaction between these resins with the elastomer..?
I did annealing of polyethylene of 200um(size 2x2 mm) on Silicon at 300 °C for 10 min. After the annealing process i saw the thickness of polyethylene increased to 500um approx!!!!!!
Can anyone explain why there is increase in the thickness of 200um to 500um of polyethylene????.
Hi, in the last days i have been reading about nbo method and i have the next doubt:
is it always reliable the bonding description of a molecular system you obtain using the NBO method? In which cases do you consider that it is necessary to have special care when analyzing the NBO results?
Hi dear all
I really need to find the EAM potential of Fe-Pt, but I don't find It in any sites.
Does anyone know how to find this EAM potential?
Please guide me
I performed calculations on metal-metal multiple bond. For the Cr-Cr system, one electron on σ*-anti-bonding, two on σ-bonding, one electron on π*-anti-bonding, two on π-bonding, the bond order for Cr-Cr is 0. However, for the Fe-Fe system, one electron on σ*-anti-bonding, two on σ-bonding, one electron on π*-anti-bonding, two on π-bonding, the bond order for Fe-Fe is 1. Why? Who can tell me on what condition the half bond could exist, please?
Dear all, Can anyone suggest few bonding gum/ adhesive solution which can use to assemble or to stick 2 layers of uncured rubber.
samples of coconut shell having specified length and width are cut. I am trying to make these samples straight/ flat as the coconut shell are curved (like an arc) in nature. Is there any way or method by which the coconut shell samples can be made straight/flat? Please provide some methods or techniques by which coconut shell shape can be modified.
My primary motive is to heat seal the PP mesh with a Silicone structure. But if its not possible, then I need to know what are other options are available.
Also, I want to know if any material other than Silicone will do the job better, given that the material has to be flexible and bio compatible.
What I wonder is that assuming I have two proteins namely protein-A, protein-B and protein A is somehow modified by protein B (simply an enzyme catalyzing the addition of -OH group to certain Proline residues in protein-A), is it feasible to acquire profound insight as to how the protein-B comes closer to the certain sites in the protein-A and initiate the interaction?. More broadly can one be able to investigate how the structure of an enzyme affect what it does in a dynamic way (conformational changes along the catalysis, how the rest of the enzyme rather than the active sites contributes to its function or any important water enzyme interaction etc.). And besides that how one should think of the catalysis process in an intuitive way. What I mean by that is in biochemistry books it is just said that "This enzyme adds Oxygen from the dioxygen in the environment....." I mean how should one imagine this process in a more physical and theoretical way ?. It really bothers me the fact that I just cannot imagine the cascade of events in a more scientific and theoretical manner. Also if these questions are so trivial forgive my ignorance on the matter. Any suggestion would be much appreciated, thanks in advance.
I am trying to understand the possible chemical bonding between the carboxylic group and SDBS. Is there anyone here to help me out about this matter? Thanks,
As through site-directed mutagensis, the catalytic activity of an enzyme is increase by analyzing there variants. But its time consuming and unpredictable when you are mutating the residues.I want to increase the activity of an enzyme by mutating there residues firstly through computational and bioinformatics analysis, then followed by experimentally among the best variants.
So by which principle i can chose to select among the active residue (interacting residue or nearby residue in the active site?) to mutate it ? Secondly how i can analysis through computationally that this variants will be have good activity as compared to wild type?. Can someone provide articles related to this work?
Thanks in advance.
It is well known that silicon interacts with lithium to form the Li-Si alloys, however, the nature of the atomic bonding between Si and Li atoms are unclear. Can you please share with me any theoretical/experimental or simulation findings about the nature of Li-Si bond?
Also, what is the best suitable simulation method to investigate the bond nature between Li and Si?
Thank you very much.
I am working with the benzoyl chlorides with methoxy substituents. In that there exists S-cis and S-trans isomers. I wish to know which of the isomer possess minimum energy in general and what parameters can affect the energy of the isomers? Kindly help me knowing the same.
There are a lot of questions here on RG how to calculate bond orders but i want to know how to interpret them.
So what does it mean when for example:
- an sp3 carbon atom has a bond order significantly smaller than 4? say 3.8.
- a sulfur atom in a thio-ether Et-S-Et for example. has a bond order significantly larger than 2. say 2.3
- is an intramolecular hydrogen bond strong or soft when the bond order is around 0.05?
Or in other way, what is the role of atomic radii and bond length distance between two atoms in the formation of covalent bonds?
Can you any one tell how to optimize La0.5Eu0.5VO4 phosphor by using atomic coordinates(x,y,z) in GAUSSIAN software?
This is the first time that I try to calculate this constant. It is a very simple case in which an organometallic complex is coordinated by a donor ligand in a 1:1 stoichiometry. However, it is under fast exchange so I can only see one set of signals. I have accumulated NMR data at different concentrations of the ligand for a fixed concentration of the organometallic compound, and I can see how the signals are shifted with the concentration of ligand. Could anyone help me to start with this, please? Thanks in advance.
I am taking cm and Columbus values. but not getting final result. So please inform. Peak under the curve in equation, where have to substitute (in which unit).
Recently, I need to bond two layers together. Does anyone have the experience to bond between Si3N4 and SiO2, or TiO2 and SiO2? We cant use the anodic bonding method as we do not have the machine. I prefer to do the bonding process at room temperature. Could anyone help me to figure it out?
Hi! I'm working on a aC-Au interface , and I would like to determine when a C and an Au atoms are bonded, based on its electronic structure. for C-C I can determine it by means of the bonding distance, but I'm not sure if the same procedure would make sense for Au-C bonding. Does anyone has any ideas? Thanks