Mar 21 2019
In a recent study, researchers have uncovered the exact molecular mechanisms that cause liquid drops to combine at a molecular level. These findings could pave the way for many different applications.
According to the study, a better understanding of how droplets of water combine at a molecular level could aid in making more accurate 3D printing technologies and may help in improving the forecasting of various weather events, including thunderstorms.
Simulated interactions
A research team from the University of Edinburgh and the University of Warwick performed molecular simulations on a supercomputer to study the interactions between very small ripples that form on the droplets’ surface. However, these tiny ripples, called thermal-capillary waves, are so small that they cannot be detected even by the most sophisticated experimental methods or by the naked eye.
Scientists discovered that these minute thermal-capillary waves cross the gap between adjacent droplets and make the initial contact between them.
The researchers informed that as soon as the droplets contact, liquid molecules draw both the surfaces together, similar to the zip on a jacket, causing the droplets to merge completely.
Liquid behavior
Analyzing the dynamics of merging droplets could provide a deeper insight into the conditions, which cause the formation of raindrops for creating storm clouds, stated the research team.
The researchers utilized the ARCHER UK National Supercomputing Service—managed by EPCC, the high-performance computing facility of the University—to perform their simulations. These simulations used a countless number of processors to model the interactions between almost five million atoms.
The Engineering and Physical Sciences Research Council supported the study, which has been reported in the journal, Physical Review Letters.
We now have a good understanding of how droplets combine at a molecular level. These insights, combined with existing knowledge, may enable us to better understand rain drop growth and development in thunderstorms, or improve the quality of printing technologies. The research could also aid in the design of next-generation liquid-cooling systems for new high-powered electronics.
Sreehari Perumanath, Lead Researcher, School of Engineering, The University of Edinburgh.
The theoretical framework developed for the waves on nanoscale droplets enabled us to understand Edinburgh's remarkable molecular simulation data. Critically, the new theory allows us to predict the behaviour of larger engineering-scale droplets, which are too big for even ARCHER to capture, and enable new experimental discoveries.
Dr James Sprittles, Mathematics Institute, The University of Warwick.