Cracking the problem of heterogeneous nucleation: identifying the sites responsible for ice nucleation

解决异质成核问题：确定导致冰成核的位点

• 批准号: 2114668
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2114668
• 关键词: Cracking; problem; heterogeneous; nucleation; identifying

A fundamental understanding of the formation of ice is critical for a range of fields. However, we have very limited knowledge of why certain materials trigger the formation of ice, while others do not. It is thought that specific sites on surfaces which are perhaps just a few 10s of nanometers squared are responsible for nucleation, but these sites can occupy only 10-10 % of the surface. Hence, they are incredibly difficult to identify and characterise and our understanding of them remains extremely poor.In this PhD project the student will focus on improving our basic knowledge of ice nucleation through novel laboratory experimentation utilising the unique equipment and resources which have been developed in the Leeds Ice Nucleation Group. The student will also be uniquely positioned to exploit their discoveries in the fields of: nucleation of ice in clouds and the control of the formation of ice in biological samples during cryopreservation. Ice nucleation in clouds helps define life on Earth since clouds play a central role in our planet's climate and its hydrological cycle, while the control of ice nucleation is a key limitation in a range of areas, such as the supply of cells for the high throughput toxicology screening of pharmaceutical products. Objectives:1. Identify nucleation sites using our existing cryo-microscope equipped with a high speed camera to study ice nucleation on thin sections of mineral samples.2. Test the response of these sites to the presence of salts and acids. We know that salts can either enhance or deactivate ice nucleation, but do not understand why. Acids can deactivate nucleation sites, but linking this deactivation to changes in surface properties has never been done before. 3. Use advanced imaging techniques to probe the properties of the sites which cause ice nucleation. 4.Potentially use the new knowledge of what makes an effective ice nucleation site in order to artificially create ice nucleation sites which might be used for the control of ice nucleation in applications such as cryopreservation. This would be an excellent opportunity to interact with our partner cryopreservation company.5. Potentially take part in a field campaign. While this project is laboratory focused, there will be opportunities to take part in field campaigns around the world where we study ice nucleation. In past campaigns we have travelled to the high Arctic, Barbados and Iceland, amongst other places. We also work on the UK research aircraft (FAAM) and research ships.

对冰的形成的基本理解对一系列领域至关重要。然而，我们对为什么某些材料会引发冰的形成，而其他材料则不会的了解非常有限。据认为，表面上可能只有几十纳米平方的特定位点负责成核，但这些位点只能占据表面的10- 10%。因此，他们是令人难以置信的难以识别和识别，我们对他们的理解仍然非常贫穷。在这个博士项目中，学生将专注于提高我们的基本知识，通过新颖的实验室实验，利用独特的设备和资源，已在利兹冰核集团开发的冰核。学生还将独特地利用他们在以下领域的发现：云中冰的成核和冷冻保存过程中生物样品中冰的形成控制。云中的冰核有助于定义地球上的生命，因为云在我们星球的气候和水文循环中发挥着核心作用，而冰核的控制是一系列领域的关键限制，例如用于药物产品的高通量毒理学筛选的细胞供应。目的：1.使用我们现有的低温显微镜，配备高速摄像机，以研究矿物样品薄切片上的冰成核，识别成核位置。测试这些部位对盐和酸的反应。我们知道盐可以增强或抑制冰成核，但不明白为什么。酸可以使成核位点失活，但将这种失活与表面性质的变化联系起来以前从未做过。3.使用先进的成像技术来探测导致冰成核的地点的特性。4.潜在地使用什么使有效的冰成核位点的新知识，以便人工地产生冰成核位点，所述冰成核位点可用于在诸如低温保存的应用中控制冰成核。这将是一个与我们的合作伙伴冷冻保存公司互动的绝佳机会。有可能参加野外活动。虽然这个项目是实验室为重点，将有机会参加在世界各地的实地活动，我们研究冰成核。在过去的活动中，我们去过北极，巴巴多斯和冰岛等地。我们还在英国研究飞机（FAAM）和研究船上工作。