Electron paramagnetic resonance (EPR) spectroscopy, also known as electron spin resonance spectroscopy (ESR), utilizes absorption of microwave radiation by unpaired electrons in a magnetic field. The interaction between the unpaired electron(s) and nearby magnetic nuclei helps identify paramagnetic species and can provide information about the motion of the molecule and the local polarity, pH, viscosity, concentration, and accessibility to other paramagnetic species. This mini‐review discusses the fundamental underpinnings of EPR needed to correctly interpret EPR spectra. We describe various types of EPR spectra encountered by chemical engineers, and use application examples drawn from the chemical engineering literature to illustrate the information available from the technique. Few chemical engineering departments or even chemistry departments have EPR instruments, which contributes to the significant barrier that prevents this being adopted as a routine measurement technique. However, in 2016 and 2017, Web of Science indexed 7000 articles that applied EPR spectroscopy. A bibliometric map categorized the keywords in four categories based on co‐occurrences: magnetic properties, films, and luminescence; crystal structure, complexes, and ligands; nanoparticles, oxidation, and degradation; and, systems, radicals, and H₂O₂.

中文翻译：

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化学工程中的实验方法：电子顺磁共振光谱法-EPR / ESR

电子顺磁共振（EPR）光谱，也称为电子自旋共振光谱（ESR），利用磁场中未成对电子吸收微波辐射。未配对电子与附近磁核之间的相互作用有助于识别顺磁性物质，并可以提供有关分子运动以及局部极性，pH，粘度，浓度以及对其他顺磁性物质的可及性的信息。本小型审查讨论了正确解释EPR光谱所需的EPR的基本基础。我们描述了化学工程师遇到的各种类型的EPR光谱，并使用从化学工程文献中提取的应用示例来说明可从该技术获得的信息。很少有化学工程部门甚至化学部门拥有EPR仪器，这造成了很大的障碍，导致无法将其用作常规测量技术。但是，在2016年和2017年，Web of Science索引了7,000条应用EPR光谱学的文章。文献索引图根据共现将关键词分为四个类别：磁性，薄膜和发光。晶体结构，络合物和配体；纳米粒子，氧化和降解；和，系统，部首和H 文献索引图根据共现将关键词分为四个类别：磁性，薄膜和发光。晶体结构，络合物和配体；纳米粒子，氧化和降解；和，系统，部首和H 文献索引图根据共现将关键词分为四个类别：磁性，薄膜和发光。晶体结构，络合物和配体；纳米粒子，氧化和降解；和，系统，部首和H₂ O ₂。