Electron Energy Loss Spectroscopy on ortho-, meta-, para-xylene

Abstract

Electron Energy Loss Spectroscopy (EELS), developed in the 1940s, has since become an invaluable tool for material scientists and chemists. EELS analyzes the electronic structure of materials by measuring the energy electrons lose as they interact with a sample, offering insights into electronic transitions and bonding characteristics.

Xylene, an aromatic hydrocarbon, exists in three isomeric forms: ortho-xylene, meta-xylene, and para-xylene. These isomers are crucial in industrial applications, such as in the petrochemical industry and household products like glues and solvents. Despite sharing the same molecular formula (C8H10), the isomers exhibit different properties, including molecular symmetry. Studying these differences using EELS provides deeper insights into their electronic structures, crucial for developing more efficient industrial processes and products.

In this pro gradu-thesis, the EELS technique is employed to study the three xylene isomers. The thesis also describes the construction and utilization of an electron energy loss spectrometer, built at the laboratory of the Nano and Molecular Systems research unit at the University of Oulu. This spectrometer's development and the study of the three xylene isomers aim to enhance understanding of their distinct behaviors. The goal is to determine if the same electronic transitions are observable across all isomers and if they can be reliably distinguished.