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### 固体核磁共振Multiple-CP定量技术的参数优化与应用研究

1. 苏州大学材料与化学化工学部, 分析测试中心, 苏州 215123
• 收稿日期:2020-09-22
• 通讯作者: 舒婕 E-mail:shujie@suda.edu.cn;lxh83@suda.edu.cn
• 作者简介:李晓虹, 女, 博士, 副教授, 主要从事液体核磁共振方法在高分子材料中的应用研究. E-mail: lxh83@suda.edu.cn
• 基金资助:
国家自然科学基金(21673148)

### Experimental Set-up and Application Research of Solid-State Nuclear Magnetic Resonance Multiple-CP Technique

ZHANG Zhilan, WANG Ning, TANG Dandan, SHU Jie(), LI Xiaohong()

1. College of Chemistry，Chemical Engineering and Materials Science，Testing and Analysis Center，Soochow University，Suzhou 215123，China
• Received:2020-09-22
• Contact: SHU Jie E-mail:shujie@suda.edu.cn;lxh83@suda.edu.cn
• Supported by:
? Supported by the National Natural Science Foundation of China(21673148)

Abstract:

The quantitative solid-state nuclear magnetic resonance（NMR） multiple-cross polarization（CP） technique attracts enormous interest of the material researchers. With proper setting of experimental parameters， Multiple-CP is capable to determine the molecular chemical structure， multi-phase composition and the component contents of blends. However， the accuracy of the testing results is sensitive to the experimental parameters which are tuned by the system parameters of the measuring samples. To gain the accurate results with high efficiency， it is necessary to reveal the influence behavior of the system parameters on experimental parameters. In this work， L-alanine， L-valine and their mixture were chosen as the model samples. Firstly， system parameters of spin-lattice relaxation time of 1H（T1，H）， cross relaxation time（TCH） and spin?lattice relaxation time of 1H in the spin?locking field$(T1ρ?H?)$ were measured. Meanwhile， the accuracy of Multiple-CP results was evaluated with the variation of three experimental parameters， including relaxation recovery time（td）， cross-polarization contact time（tp）， and cross-polarization times（n）. By comparing the data of different 13C groups， it is revealed that the setting of tp is essential to the result accuracy， which is tuned by TCH and $?T1ρ?H?$ of the system. Moreover， the values of the parameter difference between the molecular groups or blended components also affects the Multiple-CP results. Therefore， Multiple-CP is recommended to study the systems with similar TCH and $?T1ρ?H?$ values. For the blends or mixtures， the identical unit of each component is suggested chosen for determining the contents.