Dear Raman,

a) your very high amount of water (amorphous) will contribute a very, very  large background onto your XRD pattern.

b) from your cellulose sample I expect broad peaks, which you will destinguish from that background. I assume that at the positions of your cellusose peaks the back ground (due to the gel) is strongly increasing or decreasing which will make your data evaluation not easy (water has a very broad pattern with at least two peaks/shoulders) .

So I would prefer to dry the sample to get rid of that immense (water) background.

Powdering is preferred, as you mentioned above.

In order to learn about all these things I would suggest:

a) perform  an XRD measurement of your gel (without your cellulose sample),

b) perform an XRD measurement of your gel including the cellulose sample,

c) dry your sample (any way you could do it) and perform an XRD measurement, and

d) powder your (dried) sample,  and take an XRD measurement of a flat sample (smooth surface) .

e) compare all these XRD pattern and draw your conclusions.

Such an experiment is not done in a single shot.

But you will learn a lot. Good luck.

Dear Raman,

a) your very high amount of water (amorphous) will contribute a very, very  large background onto your XRD pattern.

b) from your cellulose sample I expect broad peaks, which you will destinguish from that background. I assume that at the positions of your cellusose peaks the back ground (due to the gel) is strongly increasing or decreasing which will make your data evaluation not easy (water has a very broad pattern with at least two peaks/shoulders) .

So I would prefer to dry the sample to get rid of that immense (water) background.

Powdering is preferred, as you mentioned above.

In order to learn about all these things I would suggest:

a) perform  an XRD measurement of your gel (without your cellulose sample),

b) perform an XRD measurement of your gel including the cellulose sample,

c) dry your sample (any way you could do it) and perform an XRD measurement, and

d) powder your (dried) sample,  and take an XRD measurement of a flat sample (smooth surface) .

e) compare all these XRD pattern and draw your conclusions.

Such an experiment is not done in a single shot.

But you will learn a lot. Good luck.

Dear Dr. Martens and Dr. Penttilä

I appreciate your responding soon. I try to apply your useful suggestions.

I also want to know about your opinion about following 2 methods:

_____________________

1

I centrifuged (2 times at 4000 rpm) my CNF-suspension and concentrated the suspension. Now I want cast this concentrated suspension and dry it (at 50 degree of C) to make a film or layer that is just containing pure CNF. If I send a 2*2cm specimen of this dried film to XRD analysis, Now the question is:

• 1- Is this method true for XRD analysis of CNF? ( I have got my XRD analysis in this way for my nanocomposites containing CNF)
• 2- Does this temprature affect crystal structure, crystal size and or the crystallinity of CNF?
• 3- Does aggregation or adhesiveness of the CNF chains (in the dried film of pure-CNF) affect the parameters of question 2?

_________________

2

I dried CNFsuspension by freeze drying, but I can not make it well-powdered because it is like a foam.

So:

• 1- Can I use Liquid Nitrogen and make it well-powdered?
• 2- Does grinding or smashing of freeze-dried CNF in a Porcelain Mortar containing Liquid Nitrogen affect crystal structure, crystal size and or the crystallinity of CNF?

Dear Raman,

I am not specialist in celluose handling but nevertheless I will try to give some general comments.

With respect to drying please see the answers of a recent RG question (first link)

Freeze driyng is mentioned there but also drying at 50°C, as you mentioned above.

I found a paper which reports drying at some more gentle temperature (40C°).

However thermal decomposition will take place at far well above 100°C. So 40 or even 50°C will be ok to my opinion. I do not think that these elevated temperatures close to roomtemperatur will seriously affect the XRD pattern. But please compare your results with the dry-freezed samples (I have not really found documents on temperature dependence of Cellulose XRD).

With respect to cooling with nitrogen: I do not think that cooling down will affect crystallinity aspects of the cellulose. For annealing at high temperatures these effects are observed at least for anorganic materials. I have not seen yet results with respect to change of crystallite size / crystallinity when cooling is applied.

Aggregation of CNF chains could affect the XRD pattern because you then will have a partially ordered system. You should avoid this by grinding/smashing  your  CNF.

 Crystal structure, crystal size or crystallinity (as far as these terms are accessable to cellulose at all) will not be affected by this type of crushing (Otherwise the XRD community could not rely on the results of powdered samples at all). You may do this at nitrogen temperature, when roomtemperature crushing is not working.

But let us wait for the comments of Paavo and even other colleagues.

https://www.researchgate.net/post/What_is_the_best_method_for_drying_nanocellulose

Dear Dr. Martens

Many thanks for your explanation on the subject. I studied your useful message and the link you sent. As you mentioned, I hope to see the other researchers and Dr. Penttilä's explanation or suggestion.

Dear Dr. Penttilä

Thanks for your attention and responding soon. I received good suggestions and opinions about the subject from you and Dr. Martens. I hope use your knowledge and experiences anymore.

If I face a problem on next XRD-Analysis, depending on the problem, I will put the message here or in a new question.

Thanks to both of you,

Wish you all the best and success

Hi,

I filtered cellulose nanoparticles on a filter paper and allowed them to dry at 37 degree celcius for 1 day .After that I carefully removed(peeled off) my cellulose sample. It looked same as filter paper in appearance and gave it to XRD operator (Size should be atleast (17x17) mm upto 2 mm thickness for the sample he told me)

I also tried to powder it in grinder but it turned in very small paper bits (not powder) which XRD operator refused to take.You can try .

I also have problem confirming my xrd results due to non availability of JCPDS Card .Can you help me?Below is the link.

https://www.researchgate.net/post/Can_anyone_confirm_my_xrd_results_for_cellulsoe_extracted_from_bagasse

Dear Researchers

Thanks for all your answers and guidance.

The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis for Cellulose Nano-Fibers (CNF) was successfully done based on freeze-drying. After freeze-drying of CNF suspension, a piece of the sample was taken to SEM with no further operation. For XRD, the freeze-dried sample was well-powdered in liquid nitrogen by grinding with a mortar (by hands).

The results are available in our published paper in the journal of Carbohydrate polymers through this link:

(Elsevier) Article The antimicrobial bio-nanocomposite containing non-hydrolyze...

I hope this message helps other researchers,

Regards,

Raman