Chapter 17 - Infra-Red Spectra, Electron Paramagnetic Resonance, and Proton Magnetic Thermal Analysis

Abstract

This chapter describes the characterization of the carbon alloys using the infra-red spectroscopy (IR spectra), the electron paramagnetic resonance (EPR), and the proton magnetic resonance thermal analysis (PMRTA). The broad absorption bands of the IR spectra observed using the diffuse reflectance methods—provide information about the ring size of the aromatic molecules within a sample, and the extent to which these are ordered. The sharp C–H stretching peaks are quantitatively compared with the peaks using the solid-state nuclear magnetic resonance (NMR). Two magnetic resonance methods employed pulse techniques—where the relative hydrogen contents are evaluated as the ratios to carbon contents. PMRTA, which measures the temperature dependence of the signal intensities and the relaxation times of the proton magnetic resonance, provides information about the molecular motion in the heat-treated carbons and in coals. These spectroscopic techniques give information about the composition of the carbon precursors prepared at temperatures below 500–600°C.