As a related alternative, maybe you could use Attenuated Total Reflectance (ATR) IR spectroscopy. In this method a flat sample (your paper?) is clamped tightly against a standard crystal with a flat surface (several different ones are used). The crystal must have a higher refractive index than the specimen. See https://en.wikipedia.org/wiki/Attenuated_total_reflectance 

For transmittance measurements, stain the paper with small amount of paraffin oil, attaches paper to cell holder and run the measurement.

FT-IR ATR method is very useful (It was done in my laboratory). The most convenient are ATR with diamond crystal what gives small area of contact with high pressure. It give good contact of paper fibrous with crystal what is necessary for obtain spectrum with high s/n ratio.

Examples of this kind of equipment is: Standard Golden Gate ATR Accessory - manufacturer link: http://www.specac.com/products/golden-gate-atr-ftir-accessory/standard-golden-gate-diamond-atr-accessory/513

But there are some other similar accessory.

All the best from University of Lodz

Dear Naseer,

I had the same problem some years ago. And the solution is simple if you have a DRIFT accessory. You simply cut a piece of paper sample and plunge it in pulverized KBr crystals. As much KBr naturally sticks on the surface of the paper it makes the diffuse reflectance. Just place the paper on the top of the DRIFT accessory and measure as usually. Best regards, Ildiko

Use atr

All of the suggestions above are good.  We would run this type of sample in a transmission diamond pressure cell, but this requires the cell and focusing optics.  It also works to bear down really hard in an agate mortar and pestle to grind the paper, then add a little dry KBr and grind some more.  If you can make a good KBr pellet you should get a good spectrum. 

It depends on what kind of instruments/accessory you have available to you.

-If you only have a transmission module, you will have to prepare your sample using some destructive method.

-As stated before, ATR is very useful and it doesn't require much sample treatment.

-If your paper is quite rough, you can try a DRIFT accessory. It collects the diffuse reflected IR radiation.

-If your paper is quite flat, you can try a specular reflectance module. It collects the specular reflected radiation. This method needs no sample treatment and is complete non-destructive. It only has two drawbacks:

* You have less signal than in classical (e.g. transmission) FTIR measurements

* You detect reflected IR radiation, which has interacted with your paper, as a result your spectrum has a different appearance than it would have with transmission measurements. However it is possible to assign these bands.

All the previous responses are constructive but you need to consider what is the question you want to answer. For the transmission measurements if the paper is thicker than about 10 microns some bands will be too strong. This matters if you are trying to identify the major components but not if you are looking for minor ones. With the reflection measurements the penetration depth is variable. ATR penetration depth can vary from 0.5 micron to several microns across the spectrum depending on the ATR crystal used and the pressure applied. My limited experience of plain paper is that many are a complex mixture of cellulose, inorganics and some sort of size(glue). Even some "plain" papers have a surface layer. As always with IR spectroscopy you need to match the sampling technique to the question you are trying to answer.

I agree with Geoff.  You need to know the purpose of your measurement.  I remember a few years ago some analysis that indicated that we may have a charred paper contaminant.  We produced our own reference set of spectra containiung various levels of charring up to paper ash - at that point the spectrum was predominantly calcium carbonate.  ATR is fine for a bulk measurement, but it still has rough surface so contact with the crystal may not always be what you require.  FTIR and/or Raman microscopy is a better approach for individual fibres, fillers and layers. However the starting point must be why you want to make a measuremnt of the paper. That will then define the strategy you should use. 

Geoffrey Dent is exactly right. First decide what part of the paper sample you want to analyze (e.g. surface or aggregate structiure) and then pick a method of preparing and analyzing your specimen. Would make sense to analyze both the surface and the aggregate to perhaps isolate what is just in the surface.

Also, if the source of your paper sample is known, why not ask the manufacturer about composition and coating? Maybe it is proprietary, but maybe not. 

One technique is not sufficient to characterize the composition of any sample, you need more than one technique if you are interested in knowing the composition of the paper. IR whether transmittance, KBr, ATR, etc. will give information about certain functional groups. You need additional information as pointed to know the exact composition of the paper. The question asked was very clear, How does one take FTIR spectrum of plain paper? The question did not ask about composition!!!

Usually we use ATR for paper samples, but in case you do not have one try to soak paper in water and make pulp out of it, then mix large portion of KBr into it and dry this mixture properly to remove water. Then you can crush this mixture and use it to make pellets. It should

Good luck.

It sounds ok

Try to use the Golden Gate Single Reflection Diamond ATR (http://www.specac.com/products/attenuated-total-reflectance)

You can press a specimen of your sheet of paper onto a diamond crystal at a defined pressure and take a reproducible ATR-FTIR spectrum.

Best regards,

Martin  

Thanks one and all for your valuable responses, surely it will help me. 

Tear the piece of paper to tiny pieces as you can. and mix it with KBR like powder samples.

ATR is usually quite good for plain paper. However, you should be aware on the fact that ATR is a surface technique. Namely, incident IR radiation penetrates into the sample, which depends on wavelength and (wavelength dependent) refraction indices of both ATR element and sample - penetration depth is never more than a few microns. Thus, ATR IR spectra will contain information on surface level of the sample.

On the other hand, transmission IR spectra reflect chemical composition of both surface levels and interior of the sample.

So, the method depends very much on what you're interested in.

Thank you Nashed, Biliskov for your suggestions.