Questions related to IR
The solubility test showed that the polymer has been crosslinked since it didn't dissolve; however, The FTIR spectrum doesn't show the ester peak (which is the proof of crosslinking of my polymer).
I want to make a thin section of rock transparent to IR. CaF2 slides can be used as substrate for the thin section but I need to find a glue able to whistand the polishing and that is transparent to IR in the 1000-4000 cm-1 range. Any suggestions? Thank you!
I have taken the % of Absorbance (FTIR data) of PVDF film. The following formula is used to calculate the fraction of Beta phase
fbeta= Abeta/(1.3Aalpha+Abeta) (ref: RSC Adv., 2016, 6, 20089–20094)
Where, as per literature Aalpha and Abeta are the IR absorbance at 762 and 840 cm-1. Here I don't know , how to calculate Aalpha and Abeta from my FTIR data.
help me to solve it.
In doing a meta-analysis using articles done with time-to-event analysis, I faced the problem that some authors reported the effect size (incidence density) with person-year observations, while others reported person-month observations. Some also reported the incidence density for only the exposed group (single arm). Others reported the rate ratio (the ratio of IR in the exposed group to IR in the unexposed group).
We have collected the IR spectra of two samples, one prepared with commercial graphite (Sigma Aldrich) and with a sonothermal treatment of 2h, the second with the same apparatus Vibracell Bioblock 500 W but in 5 min. We know that the first sample contains larger graphene sheets than the second, as established by TEM. The second is a mixture of 1 to 5 sheets and remaining graphite.
We have been surprised to detect that a strong absorption peak was detected at 7325 cm-1 but only with the smallest sheets. Do you agree with me, it corresponds to a border functionality? The infrared irradiation is removing absorbed water.
In that position, we are no longer in the IR range. Which range are we observing?
Can attributions to OH and peroxyde OOH groups be propose?
Hollo to all
I want to know in which region the vibrational frequency of the functional group of azomethine appears in the IR spectrum.
Especially in the case of the azomethine functional group in 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline)
I need to know if bathophenanthroline is coordinated to a metal ion, does the vibrational frequency of azomethine shift to a higher or lower region?
Thank you all in advance for your answers
A project I am working on is the evaluation of stigma temperature in outdoor conditions (solar radiation up to 800-900 W/m2 and air temperature varying between 10-30 degrees).
I am utilizing three different instruments,
1. Thermal Camera that can be attached to a cell phone (thermal expert Q1)
2. Type T thermocouples 32 AWG (0.008 inches in diameter or 0.3255 mm2)
3. IR thermometer
The instruments were calibrated with a certified digital thermometer.
When all three methods are pooled together, we notice that IR camera and thermocouples have near consistent results while the IR thermometer is nearly systematically cooler than the two other methods (of about 1.5 degrees Celsius). This is odd and difficult to explain. Also, these values for the IR thermometer always make stigma cooler than air, which would not make much physical sense as the stigmas don't have any cooling mechanisms to our knowledge. Consequently, I am wondering if anybody has had any experience with any of these three instruments in order to help me get a better understanding of what could be the issue, but most importantly which instrument is actually the best to measure temperature.
Thank you for your time,
I am currently doing my master thesis and I have to analyse an IR spectrum of multiple samples. The given sample is supposed to be a specific polymer whose individual monomers i know. It is PBAT (polybutylene adipate terephthalate) which is a random co-polymer made of adipic acid, 1,4-butanediol and terephthalic acid.
Since I have a biology background and not that much chemistry i am struggling a little bit to do the IR spectrum analysis. I read that there are programs or tool with which one can simulate or predict an IR spectrum to compare that with experiment data of actual FTIR scans of the sample.
Anyone has a suggestion what to use or any other tips for me?
Thanks alot for helping out!
Best regards Dominik
I am doing electrochemical studies for my nanocatalyst. From the research paper, I found that, for accurate results CV/LSV should be IR compensated. So I did ZIR compensation. I have attached the results that I got. Does it affect my results? If yes how to compensate it?
Please let me know...
I'm a Chemistry student currently working on a thesis that involves phytoremediation of Lead in aqueous solution using a specific plant.
The FTIR results for both the stems and leaves of the plant after phytoremediation are almost identical, having the presence of O-H stretch and C-H stretch on both IR spectrum.
The FTIR result for the roots after phytoremediation, however, showed a possible trace amount of H2O at 3457.1 cm-1 (it was a tiny peak, therefore it cannot be called an O-H stretch), along with the presence of a C-H stretch and C=O stretch.
I need help in understanding what caused this deviation from the two other samples (stems and leaves). Could it be the presence of the metal in the root sample or are there any factors that I need to consider?
Thank you to anyone who'd be willing to give their insight/s on this, it would really help me a lot.
MGIMO University is conducting the International Hierarchy Expert Survey-2022 (IHES-2022). The survey is aimed at tracking how the status and roles of states have changed since last year. We invite International Relations scholars, as well as practitioners and experts in IR and related fields to join.
To complete the questionnaire, please access the following link:
It will take an estimated 20-25 minutes to fill out the form.
This the second expert survey on international hierarchy conducted by our research team. Results of IHES-2021 have been published in an open access research paper and are attached to this discussion. However, to avoid the anchoring effect, we kindly ask participants to complete this year's survey before reading the previous results.
We guarantee confidentiality of all participants, only aggregated results will be published.
We gratefully thank you,
Research Team on International Hierarchy
Institute for International Studies,
Infrared spectroscopy measures the infrared (IR) radiation after interacting with a sample, which is directed to the spectrometer’s detector. Thus, the sample absorbs part of the IR radiation, and the difference between the IR signal before and after the interaction with the sample generates the IR spectrum. The sample’s molecules vibrate while the IR radiation interacts with them, reaching a higher energy state. However, how do the molecules stop vibrating and return to their original energy state? I’ve searched for this information in the literature, but I’ve not found a clear answer.
I would be eager to familiarize myself with your beloved journal articles or book chapters dealing with how political agency is constructed, transformed, and negotiated in IR through communication.
I am particularly interested in the contributions that focus on:
- performative approaches to agency;
- moral agency;
- constructing agency in times of security crises.
Thank you in advance!
I am working on HER and OER. I use Ni foam as working electrode substrate. While running EIS for my sample, I have the impedance spectrum starting from the negative side. i.e. The semi-circle starts at minus values of Re(Z) and ends near 1 ohm or 2 ohms on the positive side. So, I am left only with Rct value. Why does this occur? Also, for what is the Rs value in this case. How should I do IR correction, without knowing Rs?
Colleagues! Please help with information on methods for identifying somatotropin in a contraband substance. Our customs officers confiscated presumably somatotropin in ampoules. The object is new to them. They don't know how to identify it by simple methods. Does anyone have an IR spectrum of a somatotropin sample?
I have done the FT-IR characterization, but the wavenumber I get from this is not included in the IR table data. How do I know if the compound is not present in the literature?
In IR spectrum, each polymer have number of absorption bands. From those bands, how can I find the Characteristic band or a band that can be used to find out the presence of a particular polymer? Or Is there any important absorption bands or a band that best describes a polymer?
I'm working on IR camouflage project and I want to mesure the radiation power using the FLIR camera, can someone help me to know how to do it ? is there anyway to get it directly from the cameras or I have to use other softwares like Imagej?
Thank you for your help.
The IR spectral characteristics of semiconductor structures have been measured. How the LO and TO peaks are separated on the graph.
I know that NIR can be direct and diffuse, but I would like to know if the same happens with the rest of IR.
I have a very thin sample of BNNT that is heated up and I need to measure it's temperature using a long wavelength IR camera. This BNNT is of unknown emissivity and I currently unable to measure it using a spectrometer. My thinking is that I can attach or apply a layer of a material of known optical properties to the bottom of the paper so I can measure it's temperature instead. Since I will be applying a think layer, I am assuming the temperature would be the same. I am expecting the temperature of the sample to be between 300 and 500 degrees Celsius.
Now my question is what can I use? I found one Thermographic paint that I can use but the distributor is in Europe and I am in Canada, so it would take some time to obtain the paint. I am looking for other alternatives before making a decision.
If a thermal camera specifies minimum focusing distance as 20m/50m (based on the lens), it means that the bare minimum distance required to provide parallel beam on to the lens is 20m/50m to form image on to FPA.
As collimators with off-axis parabolic mirror provides parallel beam of cavity sources, is it possible to use the IR collimators for calibrating thermal imagers?
Research paper/ technical note, if available in this regard is requested
I run the CD spectra of the modified and non-modified protein and the 2ndary are the same. However, there is a change in amide I in the FTIR results. Thus, the functionalization might be expected to change the secondary structure. Kindly any suggestions with references.
I want to know the best technique that provides exact and reliable results on the chemical composition of a plastic product (geosynthetic product) with the concentration of each compound
what is the best technique among these techniques to detect the chemical composition of a plastic product based on PP: Chromatography, Thermogravimetry analysis (ATG) or Fourier transform IR spectroscopy (FTIR).
I’ve been doing some DFT calculations for the glyphosate molecule gaussian 09 program, and I need to have a reference FT IR spectrum in gas phase, thank you all
we are trying to "debug" a liquid cleaning product formulation (substances added are known, s. below), which has developed crystals over time. We isolated, washed these and got IR spectra of the crystals and all ingredients that we use (see attachments). We are however still struggling to identify what our crystals could be and what could be reacting.
We know IR is limited in identifying a complete structure. But any further help in the interpretation is appreciated. In particular with regard to the strong, semi-sharp peak at 3281 cm-1. We interpret the main peaks with the bonding types O-H, C-H, C=O and C-O. The structure is similar to triethanolamine, except for the sharp O-H peak and the peak at 1738 cm-1. However, if the triethanolamine reacted with the esters or lactone we would expect a more intense peak.
Ingredients (in order of concentration):
- Dimethyl glutarate (1,5-dimethyl pentanedioate)
- Fatty acid esters
- γ-Butyrolactone (Oxolan-2-on)
- Ethers (3-butoxypropan-2-ol, [2-(2-methoxymethylethoxy)methylethoxy]propanol) and 2-methoxy-1-(2-methoxypropoxy)propane; 2-methoxy-1-[(1-methoxypropan-2-yl)oxy]propane)
Thanks for the support,
I face a technical issue of how to measure uniformity of infrared radiation on the target surface.
Namely, the setup is as follows. A halogen lamp is mounted at the end of the pipe-lightguide (see Fig. 1). When halogen is on radiation (visible light and infrared) is delivered to the target surface (c.a. 4x4cm). Total power of the radiation delivered to the surface is high (c.a. 200W which gives 13W per cm2). What I need to know is spatial distribution of the radiation on the target surface (to be able to find out how uniform it is). The measuring unit must withstand several seconds of measuring.
Several ideas and related issues:
1. IR camera could be placed at the end of the pipe. However, any reasonable camera will be burnt at once, at least oversaturated, as the power delivered is extreme.
2. Cover IR camera with a filter. This solution does not really work as the filter heats up and further emits radiation, i.e., I do not observe real distribution which would take place with no filter applied.
3. IR photodiodes. I imagine I could place several IR photodiodes at the end of the pipe but, again, they are highly oversaturated at once and filtering, again, does not really work.
4. Thermal-reactive paper/material(?). I am in trouble to find such a material which could withstand the power needed and provide any reasonable resolution.
Do you have any ideas on that?
I have just started using ORCA and was following a YouTube tutorial series by Dr. S. Kishor => https://www.youtube.com/playlist?list=PLJIwRG-f5Gjd95jUG4cGjfSxs2gQfQAza
I'm using ORCA 5.0.3 on windows 10 with an i5 9400 processor and 500 GB A2000 Kingston RAM. In the 16th video of the series, I was introduced to IR frequencies calculation with geometry optimization with the following input -
# avogadro generated ORCA input file
# Basic Mode
# GeomOpt + Freq for Acetone
! RHF OPT FREQ 6-311++G**
* xyz 0 1
C -3.50986 2.85550 -0.14979
C -2.02053 3.03306 -0.02862
H -3.77767 1.82632 0.10157
H -3.82355 3.06176 -1.17685
H -4.01762 3.55239 0.52151
C -1.41776 2.78670 1.32795
H -1.61034 1.75505 1.63245
H -1.85017 3.48112 2.05247
H -0.33688 2.94710 1.28593
O -1.32971 3.36340 -0.99127
Now, when I'm opening the output file (.out) using Avogadro 1.2.0, the molecule was loading, but the frequencies were not loading. I checked the output file, and they were there but were not coming in Avogadro (should render automatically while opening the output file). I opened the Vibration toolbar from the settings of Avogadro to find they were not loaded. Can anyone help me how to view the IR frequencies generated from ORCA in Avogadro or other software?
N.B. - I found a discussion in the ORCA forum about OfakeG which can convert the ORCA output file into a Gaussian output file and I used that to covert as I have institutional access to Gaussian and GaussView (https://orcaforum.kofo.mpg.de/viewtopic.php?f=8&t=5018&p=21189&hilit=OfakeG#p21189). I followed the documentation but I was unable to convert the file type. I got an error saying the application couldn't find the file.
1) Output File
2) Screenshot of Avogadro window
3) Screenshot of OfakeG application window
My Hg/HgO standard electrode working properly . But It showing resultant current lesser than the Standard Calomel Electrode . Why ? drop your ideas ....TIA
As per literature,
"The net peak heights were determined by subtracting the height of the baseline directly from the total peak height. The same baseline was taken for each peak before and after exposure to UV.
The carbonyl index was calculated as: carbonyl index = IC/IR(100),
where IC represents the intensity of the carbonyl peak and IR is the intensity of the reference band."
Now, how do I substract the baseline height from the peak height???
I am preparing polymeric blends from recyclable materials. What are the characterization techniques that should be used and how to prepare the samples (IR, DRX, SEM, TEM, etc)? Could you suggest technical sources and papers/books?
Hello, I am a student researcher trying to export multiple spectra as .csv files (for graphing in Excel) in the Perkin-Elmer IR software. When I open an exported .csv file in Excel, it displays the y-values (%T) with only digits before the decimal point. I would prefer to have digits after the decimal point as well, as the graph is not very fine, and jagged. I have tried configuring the settings within the software, specifically changing "Decimal Places Y" in the Data options of the Export Setup. However this seems to have no effect on the exported data. How can I fix this? Thank you for your help.
Is OH bending IR band in PVA is related to inter/intermolecular hydrogen bond? why does it disappear on blending with another polymer?
Can anyone suggest a suitable reference?
Sea surface temperature, chlorophyll, winds, altimetry observations are done by NASA, ESA, JAXA, ISRO and a few other government institutes. Commercial satellite data providers provide very high-resolution earth observation imageries in optical, IR or UV spectrum. Are there any commercial satellites that provide SST or Chlorophyll data?
I've a HHG setup, but the IR filter is broken. This means that the entire IR intensity hits the CCD camera and would destroy it. Because a replacement filter needs a few weeks to arrive, I'm wondering if anyone has an idea how to cheaply/DIY block the IR in the vacuum before the CCD.
Many thanks in advance
How can I observe moving cells without visible light? I tried with IR LED and an IR sensitive Bresser ocular camera, but the iR light was too weak.
Pulse oximetry works by sending red and infrared light through blood vessels and measuring the absorption of the two wavelengths of light by hemoglobin. Blood also contains other proteins such as heme peroxidases which also absorb light at slightly different wavelengths. However, given that Hemoglobin is present in a much larger concentration, would it even be possible to detect other heme peroxidases through the method used in pulse oximetry even if they had different peaks?
I want to briefly know, how theoretically IR and Raman spectrum of a particular optimised structure is estimated using DFT. Actually I want to know what is the basic theory behind this in a brief way.
After doping a InN nanostructure energy gap reduces and also in Ir spectrum molar extinction coefficient value decrease. What are reasons behind this?
This strange waveform appeared today while measuring the IR background. After changing many parameters and testing many times, I still only get this waveform.
Then， sample measurement did not yield the desired waveform, so what is the reason for this waveform? Is there something wrong with the machine?
Thank you very much
Two different IR spectroscopy for the same molecule:
Note: The cyano stretching band should disappear upon cyclization of the molecule.
-The first IR spectroscopy (A) represents the cyano absorption observed in the 2190 cm-1 region.
-The second IR spectroscopy (B) represents two different stretching bands observed in the 2194 cm-1 and 2207 cm-1 regions.
Concerning the second spectroscopy (B), if the stretching band 2194 cm-1 represents the cyano group, then what functional group does the stretching band 2194 cm-1 present, or do these two stretching bands illustrate the same functional group.
Thank you for your help.
Basically, I have this protein:
Transmission-FTIR spectroscopy can be used to analyze analytes in aqueous solutions e.g. Proteins in a formulation. Critical step: In order to correctly analyze the structure of proteins, the buffer solution's spectrum needs to be subtracted from the spectrum of the sample containing proteins. However, due to differences in the amount of water that is present in each sample, the difference spectrum cannot be simply calculated by: Difference Spectrum=Protein Spectrum-Buffer Spectrum.
What is a correct method to calculate the difference spectrum for e.g. algorithm based on least squares? I have looked into many papers and the most frequent answer is that a factor is used in calculating the difference spectrum to ensure that the resulting spectrum has a 0 baseline between 1750-2000 cm-1. But using a factor results in negative peaks in the difference spectrum.
I am not familiar with solid state parameters especially in rectification ratio where my background was in biotechnology,.
Currently I want to calculate rectification ratio (RR) of my sample/device and plot some graph for my paper. However, I found it quite confusing with little to no basics. The formula for RR = IF / IR , where I can plot a graph RR versus V based on several papers that i refered. Unfortunately, I do not know how they got the value based on this table
My question is the graph that i plotted is very weird as i refered to other people's work as attached. And some paper mention use RR value above threshold voltage? I need guidance and help in calculation as well as plotting the graph RR versus voltage.
infra red heating become more popular recently because of low cost energy and efficienty , Radiant IR-Heater Tube is the most useful technology to achieve this as i know, I'm interested to collect IR generated by this kind of IR-Heater Tube in a linear fresnel concentrator for Infra red Radiations to obtain a high temperature in a centrale cynlindrical surface. This kind of IR Concentrator Exists ? Some one can advice ?
We have imidazole ring N and Imine N for coordinating to metal in 2:1 (L:M) ratio. Both are forming coordinate bind with metal. So two covalent bond is from 2 O atom of acetate group. And the complex found be 6 coordinated in this case? Is there any possibility for this. How can we confirm the structure from IR and TGA for this acetate groups?
I need to perform Thermogravimetric Analysis with Infrared Spectroscopy (TG-IR) for my samples I have checked analyticsir.in both CIMFR and NITT instutes TG-IR system not working. other than that I couldn't be able to find any other facility in India. Someone point me in the right direction. Thanks.
Can I get electroluminescence camera and IR camera , PV analyzer on rent for research work in India?
Can I get the access or work permission of solar simulator lab in India for research work in any institute?
and what can I used instead of EL camera?
please share the link.....
I have a sample with magnesium, potassium, phosphate and water. I have found a peak around 3750, is it possible to consider magnesium with OH bound in IR for this peak?
I have tried to prepare the Schiff base from tetraphenylcyclopentadienone and p-aminophenol using MeOH, AcOH, 2 drops of HCl, and short bursts of microwave radiation (800W, 3 secs for 1 min).
Although it was small scale, a product formed that was clearly a light violet color. Naturally, tetraphenylcyclopentadienone is black and p-aminophenol is actually a beige/light brown color (due to degradation from light).
The IR looks very messy and I cannot find a reference IR for this compound. Is there a chance that I have failed to actually produce the desired product due to the intense 800W Microwave radiation, or bad solvent system? Maybe the HCl was problematic? Maybe I should have used EtOH?
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.
-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.
I want to use silicon wafers for my mid-IR imaging project. I have some specifications for them from my previous lab colleagues. In our previous lab we used to buy:
3” N TYPE <1-0-0> 1-50 OHM-CM 350±10µm SEMI-Std FLATS DOUBLE SIDE POLISHED.
However, getting exact specification is proving to be an hassle!
I am not sure about some parts of the specifications. Could you please help me with the following questions?
1) If imaging data is collected in transmission mode, does the thickness of the silicon wafer matter? What I mean is change in thickness from 300um to 500 um?
2) If the imaging data is collected in transmission, does it matter if the silicon wafers are single side polished or double side polished?
3) if the imaging data is collected in transflection mode single polished silicon wafer should be fine?
Can you calculate IR and IRR p-values and CI in SPSS without using a regression model such as Poisson? I have calculated the breast cancer incidence for various groups by hand using the breast cancer incidence rates of the entire population of a country as a reference. I have calculated the p-values and CI also by hand, but I would like to check this using an analysis in SPSS. Thank you in advance.
I have recently completed my Ph.D. from the Department of Government and IR at the University of Sydney. I am currently looking for a Post-doc position in Europe. My proposed project examines religiosity and support for radicalism among the migrants in Europe.
To begin my journey as an academician/researcher, what scientific and transferable skill should I have? Knowledge or training on which quantitative or qualitative methods or data collection softwares will benefit me in future?