What Does a Broad Peak at 2θ = 20.92° Indicate in Polymer XRD Analysis?

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Discussion Overview

The discussion revolves around the interpretation of a broad peak observed at 2θ = 20.92° in X-ray diffraction (XRD) analysis of a polymer specimen. Participants explore the implications of this peak in relation to the crystallinity of the material, particularly in the context of adding fillers.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that the broad peak typically indicates amorphous material and questions whether the addition of filler makes the material "more amorphous."
  • Another participant asks for clarification on the different colored traces in the XRD results and inquires about the specific filler used, suggesting that the material appears amorphous.
  • A participant identifies the composition of the material as Chitosan + PEO + LiClO4 with added Al2O3, observing that the peak becomes broader with increasing filler content and seeks to understand its correlation to crystallinity.
  • One participant mentions an evaluation using an image processing program, indicating that while the peak widths remain identical, their amplitudes decrease with added filler, suggesting that the filler may be scattering X-rays and affecting the baseline.
  • A participant questions the source of the broad peak and notes the difficulty in separating the effects of the polymer and filler due to the stacking of traces on the intensity axis, proposing the need for additional baseline data for clearer analysis.

Areas of Agreement / Disagreement

Participants generally agree that the broad peak is indicative of amorphous characteristics in the material. However, there is no consensus on the implications of the peak broadening with added filler, and multiple views on the analysis and interpretation of the data remain present.

Contextual Notes

There are limitations regarding the interpretation of the XRD results, including the dependence on the baseline references and the need for additional data to isolate the effects of the filler from the polymer.

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TL;DR
Confusion about amorphous and crystalline region on XRD result
So i just have my XRD result (Polymer Specimen) which i use to determine crystallinity of my material, and it turns out that my material has no obvious peak, and have a broad peak which usually associated with amorphous material. I added some filler to my material and it became more and more broad but the peak stays there. does it mean my material become "more amorphous" or what does it mean
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What do the different coloured traces represent?
What was the filler you added to the polymer?

I agree, it does look like an amorphous material.
What was the isomer and catalyst?
Does it progressively crystallise over time?
 
Hii thanks for answering my question , my material was Chitosan + PEO + LiClO4 and i added Al2O3 in it, the black one represent 0% filler, red one is 3%, blue is 5%, and green is 7%.

So the trend i saw here is the peak became broader and broader, what does it correlates to the crystallinity of my material.
 
A quick evaluation in an image processing program indicates that the peaks are indentical in width but their amplitude above their baselines decreases as filler is added.

This would indicate that the filler is scattering the x-rays, thereby raising the baseline.

Measuring in "Intensity" units, starting with the Green trace at the top:
"Peak" heights above their local baseline;
80
110
130
160

Cheers,
Tom
 
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What is the source of the broad peak at 2θ = 20.92° ?

It appears that the traces are stacked on the intensity axis, with loss of the baseline references. That makes it difficult to separate out the effects of the polymer and the filler, which I suspect is part of what we are seeing.

To analyse this further, I would need to see the intensity plot baseline for the sample support without a sample, and the plot with 100% filler alone, without polymer.
 
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