Evolution of a Water Pendant Droplet: Effect of Temperature and Relative Humidity

• 作者: Agnès Smith Arnaud Alzina Etienne Portuguez Maksoud Oudjedi Philippe Michaud
• 来源期刊: 自然科学期刊(英文)
• 学科: 医学
• 关键词: PENDANT DROP Surface Tension WATER RELATIVE Humidity Temperature DRYING
• 年，卷（期）: 2017,（1）
• 页码范围: 1-20
• 页数: 20页
• 分类号: R73

摘要

As part of a better understanding of drying liquids within porous materials, measurements from 293 to 343 K of deionized water surface tension in air as a function of relative humidity are exposed. Experimental work was carried out using the pendant drop method coupled with image analysis within an adapted instrumented climatic chamber. Results show that surface tension linearly decreases when relative humidity increases. Although the effect of humidity is less compared to that of the temperature and even less compared to a surfactant impact, it must not be neglected and values have to be mentioned when dealing with water evaporation. Modifying surface tension also affects the pendant drop shape. The drying kinetics of the pendant drop volume and its outer shell are connected to this change of shape. Steam in the air can be assimilated to a wetting agent, hence a surfactant, and can be used in an environmental-friendly way to ease the drying stage. Indeed, the challenge is to limit the risk of cracking and damaging pieces during this crucial step in material processing.