RAPID: A physics-based model for droplet drying on varying surfaces and changing seasonal conditions and the implications for COVID-19 survival

新冠肺炎疫情已经造成了巨大的生命损失和经济损失。冠状病毒(SARS-CoV-2)的季节性回归将具有更大的破坏性。SARS-CoV-2传播的主要途径之一似乎是通过人们接触带有病毒飞沫的表面。病毒在表面的存活能力受液滴大小和组成、表面材料和质地以及环境温度和相对湿度的影响很大。这些因素影响了液滴在表面干燥过程中盐和其他溶质的浓度，从而强烈地影响了液滴中病毒的生存。该项目将研究液滴内病毒的生存能力及其与液滴大小、表面类型和代表季节变化的环境条件的关系。该小组将特别寻求了解病毒在附着在表面的液滴中存活减少的条件。这些信息对于公共卫生官员、病毒学家和其他致力于控制和缓解当前和未来新冠肺炎爆发的消毒工作的专家来说是至关重要的。这个项目将汇集一个由工程师、病毒学家和传染病专家组成的跨学科团队，以了解在不同季节条件下决定病毒在不同表面存活/灭绝的机制。该研究计划将计算机模拟和实验相结合，以揭示在特定于新冠肺炎场景的条件下，液滴内部会发生什么。更具体地说，这个项目将研究在不同表面上干燥的液滴中发生的热和质量传输过程。项目成果将包括关于表面干燥的携带病毒的液滴内部溶质(盐、蛋白质)浓度-时间路径的定量信息。这些路径将被量化为液滴大小、组成、环境温度和相对湿度以及表面特性的函数。新的激光和表面化学处理将被用来在很大范围内改变疏水性和亲水性，以检查这种改变对液滴干燥过程的影响。因此，该项目将揭示哪些类型的季节性条件和表面修饰将有助于降低飞滴中病毒的存活率。项目团队将把项目成果交给研究灭活病毒方法的专家。让他们掌握干燥液滴中病原体面临的热化学条件的精确知识，将使他们能够将注意力集中在有效的消毒技术上。该项目由热传输过程计划和既定的激励竞争研究计划(EPSCoR)联合资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The COVID-19 outbreak has resulted in enormous loss of lives and economic damage. Seasonal return of the coronavirus (SARS-CoV-2) will be even more devastating. One of the primary ways that SARS-CoV-2 appears to spread is through people touching surfaces with virus-laden droplets. Virus survivability on surfaces varies greatly by droplet size and composition, surface material and texture, and the ambient temperature and relative humidity. These factors impact the concentration of salt and other solutes in the process of droplets drying on surfaces, which strongly influences the survival of viruses in the droplets. This project will address survivability of viruses inside droplets and its relationship to droplet size, type of surface and ambient conditions representing seasonal variations. The team will especially seek to understand conditions under which virus survival in surface-adherent droplets is diminished. This information is crucial for public health officials, virologists, and other experts working on disinfection efforts to control and mitigate current and future COVID-19 outbreaks.This project will bring together an interdisciplinary team of engineers, virologists, and infectious disease experts to understand the mechanisms that determine virus survival/annihilation on different surfaces under varying seasonal conditions. The research plan combines computer simulations and experiments to reveal what happens inside droplets under conditions specific to COVID-19 scenarios. More specifically, this project will study the thermal and mass transport processes that occur in droplets drying on various surfaces. Project results will include quantitative information on the solute (salt, protein) concentration-time pathways in the interior of virus-carrying droplets drying on surfaces. These pathways will be quantified as functions of droplet size, composition, ambient temperature and relative humidity, and surface characteristics. Novel laser and chemical treatments of surfaces will be employed to modify hydrophobicity and hydrophilicity over a wide range to examine the effect of such modifications on droplet drying processes. This project will therefore reveal what types of seasonal conditions and surface modifications will contribute to diminished survival of viruses within droplets. The project team will transition project results to experts who study methods to deactivate viruses. Arming them with precise knowledge on the thermochemical conditions faced by the pathogens within drying droplets will enable them to focus attention on effective disinfection techniques.This project is jointly funded by the Thermal Transport Processes program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.