Evaporation of Ethanol-Water Mixture Drop on Horizontal Substrate

Abstract

This study investigates the evaporation of sessile drop comprising ethanol and water mixture on horizontal poly methyl methacrylate surface. The contact angle (h) and contact radius (R) of ethanolwater mixture drop are recorded with time, considering the impacts of presence of ethanol. With excess ethanol, the drop evaporation is principally controlled by a phase in which both the contact angle and contact radius are falling. A diffusional model assuming linear relation between contact radius and time is proposed as h ¼ eR -3 +cR -1 , where e and c denote fitting coefficients. This model correlates with the experimental data.

Evaporation of Ethanol–Water Binary Mixture Sessile Liquid Marbles

“…Evaporation mode has also been reported to change with time giving rise to distinct evaporation phases 28,29,31,32,35,36 . Similar studies have been conducted for binary mixture droplets 35,36,37,38,39,40 , where discrepancy has been reported with some theories governing evaporation of pure liquid droplets. A similar disparity exists for pure liquid marbles 18 .…”

“…M w is the molecular weight of the liquid, T is the temperature, P vs is the saturated vapour pressure, D is the diffusion coefficient, ρ is the density, RH is the relative humidity of the droplet environment, θ is the contact angle and t is time. The full expression of K and f can be found in the literature 17,19,33,34,45 For a droplet consisting of water mixed with a more volatile component, its contact radius decreases over time whilst its contact angle usually increases at first and then decreases eventually 35,37,38,39,40 .…”

“…Wang et al 39 related contact angle, θ, and contact radius, R, for the final evaporation phase using the following expression:…”

Ethanol in biorefining and dehydration of agricultural materials: energy, capital cost, and product quality implications

“…All of the constituents of the biomaterials of interest in this discussion are wetted by water and ethanol so that the equilibrium contact angles are, or rapidly approach, zero and the cosines are 187,88,89–91 giving …”

“…Figure 9 summarizes peptization temperatures and solubility data to illustrate the potential of reduced temperature for suppression of corn and wheat protein solubility in aqueous ethanol. Lipid solubility in high ethanol concentrations also can be minimized by using temperatures below the critical solution temperature for the solution/substrate combination 32,33,35–378,108…”