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DNP-enhanced NMR surface characterization

DNP 增强 NMR 表面表征

基本信息

批准号：
1410504
负责人：
Chandrasekhar Ramanathan
金额：
$ 42.9万
依托单位：
Dartmouth College
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-01 至 2018-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410504&HistoricalAwards=false
关键词：
DNP enhanced NMR surface characterization

项目摘要

With this award, the Chemical Measurement and Imaging program is supporting the research of Chandrasekhar Ramanathan of Dartmouth College to develop new techniques to study and understand the physical and chemical properties of surfaces. A number of important processes occur at the surface of materials. For example, catalysis?such as occurs in solar energy conversion processes or in catalytic converters?takes place on the surface of the catalyst. A detailed understanding of the structure of solid surfaces and their interfaces to other media is critical to the development of new catalysts and other technologies, such as highly sensitive sensors that can be used, for example, to measure groundwater contamination or detect explosives. This research develops methods based on nuclear magnetic resonance (the technology behind magnetic resonance imaging, or MRI) and applies that technique to the study of small-scale materials. The goal is to characterize the structure of these surfaces with high spatial resolution. The resulting information is then used to selectively activate specific sites on the surface to improve on their catalytic or sensing properties. The research is having a broad impact through the development of useful new technologies that will have a variety of applications in many areas. It is having a further impact through programs in local science pubs and cafes designed to communicate the science involved to a broad societal audience. Nuclear magnetic resonance (NMR) spectroscopic methods are being developed to study the physical and chemical properties of surfaces and interfaces. To compensate for the low sensitivity of NMR, dynamic nuclear polarization techniques (DNP) are being designed and optimized to both maximize the signal enhancements for surface spin species, as well as to obtain information about the local spatial ordering of the spins at nanometer and sub-nanometer length scales. In particular, the use of endogenous and exogenous polarizing agents for DNP of surface functionalized groups in silicon and silica micro- and nano-particles are being compared. Hyperpolarization is being combined with static multiple-pulse NMR techniques such as multiple-quantum spin counting experiments to probe the local ordering of the surface spins in these systems. The newly developed methods are being applied to systems such as nanoparticle surfaces and atomistically-thin layers such as Langmuir-Blodgett or functionalized graphene films, using both endogenous and exogenous polarizing agents. The goal of these studies is to get a better quantitative estimate of the size of the quenched region, the polarization transfer rates and atomic level detail about the local DNP process. A better understanding of these phenomena could, in turn, enable the use of optimal control techniques to selective excite and study certain chemical species, allowing selective maximization of enhancements.

有了这个奖项，化学测量和成像计划正在支持达特茅斯学院的Ramasekhar Ramanathan的研究，以开发新技术来研究和理解表面的物理和化学性质。许多重要的过程发生在材料的表面。比如催化？例如发生在太阳能转换过程中或催化转换器中？发生在催化剂的表面。详细了解固体表面的结构及其与其他介质的界面对于开发新催化剂和其他技术至关重要，例如可用于测量地下水污染或检测爆炸物的高灵敏度传感器。这项研究开发了基于核磁共振（磁共振成像或MRI背后的技术）的方法，并将该技术应用于小规模材料的研究。目标是以高空间分辨率表征这些表面的结构。然后，所得到的信息用于选择性地激活表面上的特定位点，以改善其催化或传感特性。这项研究正在通过开发有用的新技术产生广泛的影响，这些技术将在许多领域有各种应用。它正在通过当地科学酒吧和咖啡馆的方案产生进一步的影响，这些方案旨在向广泛的社会受众传播所涉及的科学。核磁共振（NMR）光谱方法正在开发，以研究表面和界面的物理和化学性质。为了补偿NMR的低灵敏度，动态核极化技术（DNP）正在设计和优化，以最大限度地提高表面自旋物种的信号增强，以及获得有关纳米和亚纳米长度尺度的自旋的局部空间排序的信息。特别是，正在比较内源性和外源性极化剂用于硅和二氧化硅微米和纳米颗粒中的表面官能化基团的DNP。超极化正与静态多脉冲NMR技术相结合，如多量子自旋计数实验，以探测这些系统中表面自旋的局部排序。新开发的方法正在应用于系统，如纳米颗粒表面和原子薄层，如Langmuir-Blodgett或功能化的石墨烯膜，使用内源性和外源性极化剂。这些研究的目的是得到一个更好的定量估计的淬火区域的大小，极化转移率和原子级细节的本地DNP过程。更好地理解这些现象，反过来，可以使用最佳控制技术来选择性地激发和研究某些化学物种，从而选择性地最大化增强。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

NMR study of optically hyperpolarized phosphorus donor nuclei in silicon

硅中光学超极化磷供体核的核磁共振研究

DOI：
10.1103/physrevb.98.180405
发表时间：
2018
期刊：
Physical Review B
影响因子：
3.7
作者：
Gumann, P.;Haas, H.;Sheldon, S.;Zhu, L.;Deshpande, R.;Alexander, T.;Thewalt, M. L. W.;Cory, D. G.;Ramanathan, C.
通讯作者：
Ramanathan, C.

DNP-NMR of surface hydrogen on silicon microparticles

硅微粒表面氢的 DNP-NMR

DOI：
10.1016/j.ssnmr.2019.04.008
发表时间：
2019
期刊：
Solid State Nuclear Magnetic Resonance
影响因子：
3.2
作者：
Shimon, Daphna;van Schooten, Kipp J.;Paul, Subhradip;Peng, Zaili;Takahashi, Susumu;Köckenberger, Walter;Ramanathan, Chandrasekhar
通讯作者：
Ramanathan, Chandrasekhar

Superadiabatic control of quantum operations

DOI：
10.1103/physreva.93.052329
发表时间：
2015-12
期刊：
Physical Review A
影响因子：
2.9
作者：
Jonathan Vandermause;C. Ramanathan
通讯作者：
Jonathan Vandermause;C. Ramanathan

Optical Dependence of Electrically Detected Magnetic Resonance in Lightly Doped Si:P Devices

轻掺杂 Si:P 器件中电检测磁共振的光学依赖性

DOI：
10.1103/physrevapplied.7.064028
发表时间：
2017
期刊：
Physical Review Applied
影响因子：
4.6
作者：
Zhu, Lihuang;van Schooten, Kipp J.;Guy, Mallory L.;Ramanathan, Chandrasekhar
通讯作者：
Ramanathan, Chandrasekhar

Chemisorption of Water on the Surface of Silicon Microparticles Measured by Dynamic Nuclear Polarization Enhanced NMR

动态核极化增强核磁共振测量硅微粒表面水的化学吸附

DOI：
10.1021/acs.jpcc.6b11065
发表时间：
2017
期刊：
The Journal of Physical Chemistry C
影响因子：
0
作者：
Guy, Mallory L.;van Schooten, Kipp J.;Zhu, Lihuang;Ramanathan, Chandrasekhar
通讯作者：
Ramanathan, Chandrasekhar