The ATR PRO 610X includes built-in KRS-5 wire grid infrared polarizers. Using this accessory, it is possible to analyze molecular orientation in materials such as liquid crystals and polymers.
We will introduce a method to analyze the molecular orientation of the stretched film in the stretching direction, vertical direction, and depth direction.
If the film is stretched in the direction of light travel and the sample is irradiated with vertically polarized light (s-polarized light), the orientation information for the y-direction, that is, the vertical direction of the sample, can be obtained.
Furthermore, by rotating the sample 90 ° and analyzing it in combination with the data obtained by irradiating it with s-polarized light and p-polarized light in the same way, all molecular orientation information regarding the stretching direction, vertical direction, and depth direction can be obtained.
The ATR PRO610S polarizer mounts on both the input and output paths of the accessory and can be inserted or removed as shown in the figure below.
* You can use it as a normal ATR by removing the polarizer.
The angle of the polarizer can be set with the angle dial.
Scale value 0 ° → Linearly polarized light parallel to the prism surface is transmitted.
Scale value 90 ° → Linearly polarized light perpendicular to the prism surface is transmitted.
Differences were measured when standard twisted nematic liquid crystal (TN liquid crystal) molecules were irradiated with p-polarized light and s-polarized light. Focusing on the peak attributed to the nitrile group at the end of the liquid crystal molecular chain, it can be seen that s-polarized light has a higher absorbance than p-polarized light. Further analysis based on the obtained data revealed that the nitrile groups were arranged almost parallel to the prism, which is consistent with the knowledge of general TN liquid crystal.
