Bénard-Marangoni instability driven by moisture absorption

¹ Department of Mechanical and Aerospace Engineering, Princeton University - Princeton, NJ 08544, USA
² Faculty of Aerospace Engineering, Technion-Israel Institute of Technology - Haifa 32000, Israel

Received: 16 December 2015
Accepted: 25 January 2016

Abstract

Glycerol is a viscous liquid widely used in industry and known for its strong hygroscopic nature. While this unusual property has been well documented from the perspective of solution chemistry, its impact on the mechanical properties of glycerol remains largely unknown. Here, we report a spontaneous Bénard-Marangoni instability in pure glycerol driven by absorption of water vapor. Even under standard laboratory conditions, ambient humidity is sufficient to drive distinct Bénard-Marangoni convection cells for hours. We describe the mechanism of this instability in terms of the vapor transport process and competition between solutal and thermal Marangoni forces, and provide insight into potential uses and impact of this aspect of dynamics driven by moisture absorption in various common settings.