【摘要】 采用粒径为纳米级颗粒的液滴作为研究对象,对比纯水液滴的蒸发过程,发现接触线在基板上的钉扎源于颗粒随毛细流向外移动到接触线处、在接触线附近的沉积聚集作用,最后出现了类似于“咖啡环”的环状干燥图案。随着颗粒质量分数的递增,发现蒸发过程中接触角及接触半径也相应发生变化,验证了液滴蒸发的三种蒸发模式。同时发现并解释了粘滑移动现象,以及不同粒径下发生该现象的浓度范围规律。更多还原

【Abstract】 Using droplets containing SiO₂ nanoparticles as the research object,observing pure water droplets evaporation process,it has found that the contact line pinned on the substrate results from nanoparticles moving to the contact line with compensation flow,and gathering near the contact line.Finally it turns up the “coffee ring”.In the process of evaporation the contact angle and the contact radius changed with increasing mass fraction of particles.It also verified the three evaporation model of droplet evaporation.Then the stick-slip motion phenomenon with different concentration and size of nanoparticles was found and explained.更多还原