Buoyancy-induced on-the-spot mixing in droplets evaporating on nonwetting surfaces

Spatiotemporal infrared measurement of interface temperatures during water droplet evaporation on a nonwetting substrate

“…The volume and contact angle evolution of the droplets are plotted with respect to time in Figure 3 at intervals of 30 s. As shown in Figure 3(a), the volume decreases in a similar, exponential trend to those reported in the literature. 5,31 The evaporation rate increases significantly with increasing substrate temperature. The contact line remains pinned and the evaporation primarily follows a constant-contact radius mode; as shown in Figure 3(b), the contact radius is nearly constant during the course of evaporation.…”

Ice-dependent liquid-phase convective cells during the melting of frozen sessile droplets containing water and multiwall carbon nanotubes

“…Destabilized samples were not tested due to the risk of instrument contamination. The three-phase contact angle for all three samples types was measured using a goniometer and found to be 107-109°, which is comparable to literature values of approximately 110° [43]. One explanation for the increased driving force needed for convection to occur surrounds the MWCNT agglomerates acting as impurities.…”

“…With the heated lower boundary and the cold ice phase as the upper boundary, the interfacial traction between vertical fluid elements would result in an ascending motion along the liquid/air interface and a descending motion in the center of the droplet [44,45,[47][48][49]. Buoyancydriven flow within droplets, as a volume process, has typically been reported to manifest in a pattern opposite to this [43]. The surface-tension driven mechanism is further supported by the notion that the impetus for circulation visibly originates at the edge.…”

“…Table 2 suggests that speed increases with driving force, however the values between 10 and 30°C are within error. Speed corrections for optical distortion were not performed due to software limitations but could provide more accurate estimates [43].…”

Strong rotating flow in stationary droplets in low power budget using wire electrode configuration

“…Although acoustic excitation shows efficient mixing performance, certain drawbacks, such as execution of mixing process on a certain spot, prohibit its application in some cases . Evaporation‐induced mixing of droplet shows a cost‐effective method . However, application of high temperature (∼50°C) limits its application in the fields of biochemical analysis and biomedical synthesis due to damage of the biosample above a threshold temperature ( K) .…”