Student Video Creating Mathematica Functions to Determine Degree of Crystallinity from XRD Plots
STUDENT: Materials are often classified as crystalline, semi-crystalline, or amorphous. Most polymers are semi-crystalline. This means a fraction of the material is amorphous and lacks order in arrangements of polymer chains, while the remainder of the material exhibits parallel, well-ordered chains that define crystalline regions. There are several methods for determining the degree of crystallinity in a polymer. X-ray diffraction can be used to determine degree of crystallinity, because intensity of X-ray diffraction reflection is proportional to the material density. An X-ray diffraction pattern displays both sharp Bragg's peaks, arising from the crystalline portion, and a broad diffraction peak caused by scattering from the amorphous portion of the polymer. The degree of crystallinity can be determined using this formula, where the total integrated intensities, all of the sharp peaks, are divided by the integrated intensities of all peaks, including that of the am...