Abstract We explore the capability of 1H NMR spectroscopy, relaxation and diffusion for the characterization of thermally-induced degradation of fresh motor oils. Temperature dependent measurements of diffusion show a weak sensitivity to thermal degradation. In contrast, both the transverse relaxation at 1H Larmor frequencies of 20 MHz and 400 MHz, as well as the longitudinal relaxation at 60 kHz showed to be sensitive to thermally-induced effects at measured temperatures within the range −10 °C to 30 °C. Results show that the highest sensitivity significance can be reached by fast field-cycling NMR relaxometry measurements at low magnetic fields.

中文翻译：

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使用 1H-NMR 光谱法、扩散法和弛豫法来表征机油的热诱导降解

摘要 我们探索了 1H NMR 光谱、弛豫和扩散在表征新鲜机油的热诱导降解方面的能力。扩散的温度相关测量显示对热降解的弱敏感性。相比之下，20 MHz 和 400 MHz 的 1H 拉莫尔频率的横向弛豫以及 60 kHz 的纵向弛豫都显示出对 -10 °C 至 30 °C 范围内测量温度下的热诱导效应敏感. 结果表明，通过在低磁场下进行快速场循环 NMR 弛豫测量可以达到最高的灵敏度显着性。