We investigated the organization of micrometric hydrophilic beads (glass or basalt) immersed in Leidenfrost drops. Starting from a large volume of water compared to the volume of the beads, while the liquid evaporates, we observed that the grains are eventually trapped at the interface of the droplet and accumulate. At a moment, the grains entirely cover the droplet. We measured the surface are...

The evaporation characteristics of sessile water droplets on smooth hydrophobic and structured superhydrophobic heated surfaces are experimentally investigated. Droplets placed on the hierarchical superhydrophobic surface subtend a very high contact angle (∼160°) and demonstrate low roll-off angle (∼1°), while the hydrophobic substrate supports corresponding values of 120° and ∼10°. The substra...

Evaporation rates are predicted and important transport mechanisms identified for evaporation of water droplets on hydrophobic (contact angle ~110°) and superhydrophobic (contact angle ~160°) substrates. Analytical models for droplet evaporation in the literature are usually simplified to include only vapor diffusion in the gas domain, and the system is assumed to be isothermal. In the comprehe...

A bulk acoustic mode micro-electro-mechanical dual resonator platform is utilised to study the evaporation of sub-microliter water droplets from the surface of the resonator. An analytical formulation for the observed frequency shift and the measure dependence of resonant frequency on the modes of evaporation which is consistent with the optically derived data. The resonators access only a thin...

A numerical solution for the problem of film evaporation of a liquid droplet on a horizontal surface is presented. The droplets are small enough to be assumed spherical. Two principal cases are considered : (1) the horizontal surface is maintained at a constant temperature (case I), and (2) the surface is insulated while the ambience is hot (case II). The complete set of equations governing thi...

Abstract A mathematical model for the quasi-steady evaporation of a thin liquid droplet on a thin substrate that incorporates the dependence of the saturation concentration of vapour at the free surface of the droplet on temperature is used to examine an atypical situation in which the substrate has a high thermal resistance relative to the droplet (i.e. it is highly insulating and/or is thick ...

Using high-resolution mass spectrometry, we have studied the synthesis of isoquinoline in a charged electrospray droplet and the complexation between cytochrome c and maltose in a fused droplet to investigate the feasibility of droplets to drive reactions (both covalent and noncovalent interactions) at a faster rate than that observed in conventional bulk solution. In both the cases we found ma...