| Wed February 28th 2024 16:00 – 17:00 ZH286 | Seminar | High-resolution, marker-free measurement of concentration gradients in sessile glycerol/water droplets by Raman spectroscopy and NMR Alexander Erb |
Details:Evaporation of sessile multi-component droplets is ubiquitous in many everyday, natural, and industrial processes. Applications include printing, cooling, and coating processes. During droplet evaporation, thermal and/or surface tension gradients can occur. These can induce convection resulting in concentration gradients. Recently, Diddens et al. proposed a phase diagram categorizing inner droplet flows by their Marangoni and Reynolds numbers. However, non-invasive marker-free experimental evidence for the concentration fields proposed is still sought.In this talk, Raman spectroscopy and Nuclear magnetic resonance imaging (NMR) will be introduced as two methods that solve the above problem. Hereby the complementary character of these two methods will become apparent. Results for different concentrations of 4.2 μl glycerol/water droplets will be presented and compared to the works by Diddens et al. The presented findings will be of importance in the development and optimization of inks, medical diagnostic devices, food processing, and many more. They might additionally provide the experimental concentration fields sought for in the optimization of simulations. | ||
