Organic vapour detection with nanoparticle suspended salt solution droplet and the effect of viscosity and vapour-source distance

摘要

A novel detection method of organic vapours has been studied. The vapour of different organic solvents creates a surface tension gradient on the surface of the droplet when the vapour source is brought near the vicinity of the droplet. The surface tension gradient creates a circulation or flow inside the liquid due to solutal Marangoni effect. The circulation of the liquid is electrically detected using a multimeter by measuring the change in electrical resistance across the droplet. The change in electrical resistance due to droplet rotation is found to be different for different vapours. Further, the effect of droplet viscosity and source distance have significant influence on the electrical response of the system. For example, with increasing viscosity and source distance, the change in electrical resistance decreases. To illustrate the phenomenon and explain the effect of viscosity and vapour source distance, a computational fluid dynamic simulation (CFD) has been implemented.