Evaporation and crystallization of NaCl-water droplets suspended in air by acoustic levitation

On the Chemistry of Aqueous Ammonium Acetate Droplets during Native Electrospray Ionization Mass Spectrometry

“…A concentrated aqueous NH 4 Ac solution was kept at 80 ° C in a beaker for 2 h, causing all of the water and 93% of the NH 4 Ac to evaporate (Figure ). The near-complete vaporization of NH 4 Ac in Figure is in striking contrast to solutions of nonvolatile salts such as NaCl, where all of the solutes stay behind as solid residue after water evaporation …”

“…The near-complete vaporization of NH 4 Ac in Figure 2 is in striking contrast to solutions of nonvolatile salts such as NaCl, where all of the solutes stay behind as solid residue after water evaporation. 73 Figure 3 compares the behavior of NaCl and NH 4 Ac in native ESI-MS. Protein mass spectra generated with NaCl show extensive peak tailing due to the formation of heterogeneous [M + zH + n(Na − H) + m(Cl + H)] z+ adducts, illustrated in Figure 3A for lysozyme.…”

Evaporation issues of acoustically levitated fuel droplets

“…Buchholz [20] (2021) studied the drying mechanism using a dynamic model in which convective flow was used to analyze heat and mass transfer first, and then the mass balance was used to estimate the evaporation rate. Bunio et al [108] (2022) developed a 3D-printed acoustic suspension apparatus to analyze the evaporation of NaCl solutions. To precisely estimate the evaporation of salt solutions, the diffusion coefficient of water vapor in the air needs to be improved.…”

“…Raising the concentration of NaCl inside a water droplet was shown to accelerate water evaporation [108] ( Figs. 4 a – c), whereas in [67] , the droplet evaporation rate decreased as salt concentration increased.…”

An investigative study into an oscillatory reaction in acoustically levitated droplets

“…Thus, objects are levitated around pressure nodes. Acoustically levitated droplets have so far successfully been applied for a range of applications including sample preparation, 19 acid–base titrations, 20 synthesis, 15,21 crystallisation, 22 enzymatic assays, 23 and chemical analysis. 21 However, there are no reports on the use of acoustically levitated droplets for performing oscillatory chemical reactions.…”