There are two different types of electron microscopes, scanning electron microscopes (SEM) and transmission electron microscopes (TEM). In the TEM method, an electron beam passes through an extremely thin section of the specimen.
It is an independent method to determine the amount of crystalline matter present in the fiber. W. L. Bragg presented a simple explanation of the diffracted beams from a crystal. When X-ray beam is incident on a crystal, it strongly reflected wherever its layers of atoms at an angle show in fig. Such that, nλ=2dsinθ
Infra-red (IR) spectroscopy is one of the most common and widely used spectroscopic techniques. When electromagnetic waves interact with matter, they are scattered and absorbed. Infrared spectroscopy, radiation with wavelengths between 1 -15 μm is absorbed at certain characteristic frequencies, which yield structural information.
Amorphous region of the fiber is defined as the region of the fiber where there is no longer the order of chain molecules. The polymer chains are randomly placed in amorphous region. As a result, there is more air space in the amorphous fiber.