NMR Diffusion and Relaxation for Monitoring of Degradation in Motor Oils
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- 作者：Eva Förster ; Hermann Nirschl ; Gisela Guthausen
- 刊名：Applied Magnetic Resonance
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：48
- 期：1
- 页码：51-65
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Solid State Physics; Spectroscopy/Spectrometry; Atoms and Molecules in Strong Fields, Laser Matter Interaction; Physical Chemistry; Organic Chemistry;
- 出版者：Springer Vienna
- ISSN：1613-7507
- 卷排序：48
文摘
Different nuclear magnetic resonance (NMR) methods such as spectroscopy, diffusometry and relaxometry are applied with the aim to monitor motor oil degradation. Chemical degradation is detected by 1H NMR spectroscopy. With respect to quality control, low-field NMR is the established technique, which mostly uses relaxation and diffusion. Conventional methods such as mono-exponential data modeling lead to inadequate description of relaxation and diffusion data of complex fluids like motor oils. Inverse Laplace transform has difficulties in quantification, comparability and interpretation. Therefore, various data processing approaches are investigated to obtain the physico-chemically and numerically most correct description of the data. The gamma distribution model for diffusion and also for T1 and T2 relaxation data numerically describes the data with high accuracy. Three differently degraded motor oils were exemplarily investigated with regard to spectroscopic, relaxation and diffusion parameters.