通过TD-NMR对聚合物颗粒悬浮的研究,将表面化学与表面放松性相关联
Murilo T Suekuni1, Alan M Allgeier1
1Department of Chemical and Petroleum Engineering, The Center for Environmentally Beneficial Catalysis, and The Institute for Sustainable Engineering, University of Kansas, Lawrence, Kansas 66045, United States.
JACS Au
|October 27, 2023
概括
表面化学显著影响时间域核磁共振 (TD-NMR) 测量的溶剂自旋放松率. 极地功能组影响与水和n-decane的相互作用,影响湿透性和材料性能.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 分析化学 分析化学
背景情况:
- 表面化学在流体表面相互作用中起着至关重要的作用.
- 时域核磁共振 (TD-NMR) 是检测这些相互作用的强大技术.
- 了解溶剂放松动态对于优化材料性能和工业流程至关重要.
研究的目的:
- 用TD-NMR研究聚合物表面化学对溶剂旋转放松率的影响.
- 量化表面功能组,可湿性和NMR表面放松性之间的关系.
- 确定控制溶剂表面相互作用的关键表面特性.
主要方法:
- 用受控的表面化学方法在水和n-decane中制备聚合物颗粒悬浮剂.
- 使用TD-NMR测量溶剂横向放松速率.
- 计算NMR表面放松率 (ρ2).
- 接触角度测量以评估可湿性.
- 多重线性回归分析以将表面特性与放松性相关联.
主要成果:
- 表面极性功能组与水的相互作用比n-decane更强.
- 核磁共振表面放松度 (ρ2) 范围为水的0.4~8.0μm s−1和n-decane的0.3~5.4μm s−1.
- 观察到水和接触角测量的 ρ2 之间存在强烈的逆相关性.
- 表面成分 (H/C比,异原子含量) 是表面放松度的主要驱动因素,超过晶度和颗粒大小.
结论:
- 表面化学是TD-NMR测量溶剂放松的一个主要因素.
- TD-NMR提供了一种定量方法来评估流体表面相互作用和可湿性.
- 这些发现为利用TD-NMR来表征多孔介质和设计先进材料提供了基础.
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