Spreading of respiratory diseases, such as COVID-19, from contaminated surfaces is dependent on the drying time of the deposited droplets containing the virus. The evaporation rate depends on environmental conditions, such as ambient temperature and relative humidity and physical properties (e.g., droplet volume, contact angle and composition). The respiratory droplets contain salt (NaCl), protein (mucin), and surfactant (dipalmitoylphosphatidylcholine) in addition to water, which are expected to influence the evaporation in a big way. A diffusion-based theoretical model for estimating the drying time is developed which takes into account the dynamic contact angle of saliva droplets laden with salt and insoluble surfactants. The effect of the initial volume, contact angle, salinity, surfactant concentration, ambient temperature and relative humidity on the drying time of droplets is investigated.

呼吸道疾病（例如COVID-19）从受污染表面的传播取决于沉积的含有病毒的液滴的干燥时间。蒸发速率取决于环境条件，例如环境温度和相对湿度以及物理特性（例如，液滴体积，接触角和组成）。除水以外，呼吸滴还包含盐（NaCl），蛋白质（粘蛋白）和表面活性剂（二棕榈酰磷脂酰胆碱），它们有望在很大程度上影响蒸发。建立了基于扩散的估计干燥时间的理论模型，该模型考虑了充满盐和不溶性表面活性剂的唾液液滴的动态接触角。初始体积，接触角，盐度，表面活性剂浓度的影响，