ICE Chemistry And Physics: Astrophysics, Dynamics and Environment (ICECAPADE)

ICE 化学和物理：天体物理学、动力学和环境 (ICECAPADE)

基本信息

批准号：
RGPIN-2017-05395
负责人：
Ayotte, Patrick
金额：
$ 2.04万
依托单位：
Université de Sherbrooke
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2019
资助国家：
加拿大
起止时间：
2019-01-01 至 2020-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=682430
关键词：
ICE Chemistry Physics Astrophysics Dynamics

项目摘要

Innovative applications of molecular beam methods will be deployed to study elementary heterogeneous (photo)chemical processes on ice surfaces which are of interest to develop molecular-level interpretations for astrophysical phenomena in the interstellar medium, for fundamental interfacial chemical dynamics and for atmospheric chemistry processes relevant to the polar boundary layer.*******We propose to use a novel methodology based on a recently developed magnetically focused molecular beam source, enabling the production of water vapor highly enriched in the ortho-H2O nuclear spin isomers, to devise and optimize separation strategies and the transfer of ortho-H2O, and of the resulting spin polarisation, to the condensed phase and surfaces. Confinement effects are germane to any storage methodologies therefore, we propose to perform systematic studies of nuclear spin conversion that will shed light on intra- and inter-molecular contributions to the underlying mechanism. This may contribute to improve storage strategies thereby extending the lifetime of condensed phase water samples enriched in ortho-H2O. These methodological developments will set the stage for fundamental interfacial chemical dynamics, heterogeneous catalysis of nuclear spin conversion and important NMR spectroscopy applications as well as for laboratory studies of the behavior of the nuclear spin isomers of water observed in comae and protoplanetary disks.*******Photochemical processes are often enhanced in molecules adsorbed onto ice surfaces due to their peculiar solvation environment. We will use thin amorphous solid water films as surrogates for the quasi-liquid layer that resides at the ice surface in the natural environment and study the surface specificity of elementary processes responsible for intense NOx photochemical fluxes that emanate from the sunlit snowpack to the boundary layer upon polar Spring. Using our molecular beam/surface spectroscopy and kinetics methodology, as well as ultrafast spectroscopic techniques, we will investigate heterogeneous NO2 hydrolysis and photolysis in/on condensed water and provide improved mechanistic descriptions and quantitative kinetic parameters. This will advance kinetic modelling efforts of the complex coupled kinetics involved in this important natural phenomenon.*******Finally, environmental cryogenic electron microscopy studies of the heterogeneous nucleation and growth of ice will reveal the role played by substrate properties and growth conditions on the structure and morphology of thin vapor-deposited ice films which contribute to the interpretation of our spectroscopic/kinetics work. They will be pursued in concert within our FQR-NT funded project, sponsored by industrial partner Rio Tinto-Alcan International Limited, on the mitigation of mineral dust emissions at the Site de Disposition des Résidus de Bauxite, Jonquière, Qc.*****

分子束方法的创新应用将部署以研究冰表面上的基本异质（照片）化学过程，在冰面上进行化学过程，这是为了开发出天体物理现象的分子水平解释，以在基本的界面化学型和大气化学方面与北极相关。分子束源，使水蒸气的产生高度富集在Ortho-H2O核旋转异构体中，以设计和优化分离策略，以及Ortho-H2O的分离策略，以及由此产生的自旋极化到凝聚相和表面的转移。限制效应对任何存储方法都是依赖的，因此，我们建议对核自旋转化进行系统研究，以阐明对基本机制的分子内和分子间贡献。这可能有助于改善存储策略，从而延长富含Ortho-H2O的冷凝相样水样品的寿命。这些方法上的发展将为基本界面化学动力学，核自旋转化的异质催化以及重要的NMR光谱应用的应用以及对Comae和协议磁盘中的核自旋异构体行为的实验室研究。我们将使用薄薄的无定形固体水膜作为定位层的替代层，该层位于自然环境中的冰表面，并研究负责强烈的NOX光化通量的基本过程的表面特异性，这些过程从阳光雪花上散发到极性弹簧的边界层。使用我们的分子束/表面光谱和动力学方法，以及超快的光谱技术，我们将在凝结水中/在凝结水上进行异质NO2水解和光解，并提供改进的机械描述和定量的动力学参数。这将推动这种重要自然现象所涉及的复杂耦合动力学的动力学建模工作。他们将在我们的FQR-NT资助的项目中共同追求，由工业合作伙伴Rio Tinto-Alcan International Limited赞助，以减轻矿物质灰尘排放，该地点在QC. ****的Jonquière，Jonquière，Jonquière，desRésidusdesRésidusdesRésidusdesRésidusdes dispotition。