English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We experimentally investigate the evaporation dynamics of sessile droplets ofa fixed volume consisting of different compositions of ethanol-water binarymixture at different substrate temperatures (T_s). At T_s=25oC, we observepinned-stage linear evaporation for pure droplets, but a binary dropletundergoes two distinct evaporation stages: an early pinned stage and a laterreceding stage. In the binary droplet, the more volatile ethanol, evaporatesfaster leading to a nonlinear trend in the evaporation process at the earlystage. The phenomenon observed in the present study at T_s=25oC is similar tothat presented by previous researchers at room temperature. More interestingdynamics is observed in the evaporation process of a binary droplet at anelevated substrate temperature. We found that the lifetime of the dropletexhibits a non-monotonic trend with the increase in ethanol concentration inthe binary mixture, which {can be attributed to} the non-ideal behaviour ofwater-ethanol binary mixtures. Increasing T_s decreases the lifetime of the(50\% ethanol + 50 \% water) binary droplet in a logarithmic scale. For thiscomposition, at T_s=60oC, we observed an early spreading stage, an intermediatepinned stage and a late receding stage of evaporation. Unlike T_s=25oC, at theearly times of the evaporation process, the contact angle of the droplet ofpure water at T_s=60oC is greater than 90. Late stage interfacial instabilityand even droplet break-up are observed for some (though not all) binary mixturecompositions. The evaporation dynamics for different compositions at T_s=60oCexhibit a self-similar trend. Finally, the evaporation rates of pure and binarydroplets at different substrate temperatures are compared against a theoreticalmodel developed for pure and binary mixture droplets.

Evaporation of ethanol-water droplet at different substrate temperatures and compositions