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

COVID-19爆发已导致巨大的生命损失和经济损失。冠状病毒（SARS-CoV-2）的季节性回归将更具破坏性。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的飞沫的表面。表面上的病毒存活率因液滴大小和成分、表面材料和质地以及环境温度和相对湿度而有很大差异。这些因素影响了液滴在表面上干燥过程中盐和其他溶质的浓度，这强烈影响了液滴中病毒的存活。该项目将研究病毒在液滴中的存活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。该团队将特别寻求了解病毒在表面粘附液滴中存活减少的条件。这一信息对于公共卫生官员、病毒学家和其他致力于消毒工作以控制和缓解当前和未来COVID-19疫情的专家至关重要。该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，了解在不同季节条件下决定病毒在不同表面存活/消灭的机制。该研究计划结合了计算机模拟和实验，以揭示在COVID-19特定条件下液滴内部发生的情况。更具体地说，该项目将研究在各种表面上干燥的液滴中发生的热量和质量传输过程。项目结果将包括在表面上干燥的携带病毒的液滴内部的溶质（盐，蛋白质）浓度-时间途径的定量信息。这些途径将被量化为液滴大小，成分，环境温度和相对湿度，以及表面特性的函数。新颖的激光和化学表面处理将被用来修改疏水性和亲水性在很宽的范围内，以检查这种修改对液滴干燥过程的影响。因此，该项目将揭示什么类型的季节性条件和表面修饰将有助于减少病毒在液滴中的存活。项目小组将把项目结果转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所面临的热化学条件的精确知识，将使他们能够专注于有效的消毒技术。该项目由热传输过程计划和刺激竞争研究的既定计划（EPSCoR）共同资助该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响进行评估，被认为值得支持审查标准。

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.