Acceleration of aqueous nano-film evaporation by applying parallel electric field: A molecular dynamics simulation

Abstract

In this work, molecular dynamics simulation has been applied to investigate the influence of external electric field on the evaporation of the aqueous nano-film. The evaporation of the aqueous nano-film with 2240 water molecules and 50 NaCl on a gold (100) surface is analyzed at the electric fields with various intensities (0, 0.05, 0.1, 0.2 and 0.3 V nm -1 ) and directions. The predictions show that the evaporation of aqueous film is remarkably enhanced when the electric field Ex=0.2 or 0.3 V nm -1 is parallel to the aqueous film surface. It is also noted that free ions in the aqueous film are accelerated under the action of the higher Ex and water molecules in the hydration shell move together with the ions due to the hydration effect. As a result, the interaction between water molecules decreases, which is responsible for increasing the evaporation of the aqueous film under the action of the higher Ex. While applying the electric field Ey=  0.3 V nm -1 perpendicular to the aqueous film, ions cannot be in accelerated motion due to the existence of a solid-liquid interface and a liquid-gas surface in y-direction. Therefore, the evaporation enhancement is much lower than that of the aqueous film under the action of the Ex.

Electric Charge-Induced Active Control of Nucleate and Rapid Film Boiling at the Nanoscale: a Molecular Perspective

“…In our previous work, equivalence in the evaporation pattern with only a heat input has been shown with only an electric field . Though similar studies on evaporation of water or different aqueous films can be found in the literature, significantly less research has been done in understanding the film boiling and at the molecular level in the presence of an electric field. Similarly, molecular-level study of nucleate boiling on smooth surfaces, on surfaces with cavities, and on surfaces with varying wettabilities can be seen in the literature, but the effect of an electric field is yet to be explored.…”

“…A lower L-J interaction will simulate a non-wetting surface, while a higher value will mimic the hydrophilic behavior of the surface. 18 Therefore, the L-J parameter values considered for simulating the two surfaces are ε CuO = 0.3 kcal/mol (for surface A) and ε CuO = 1.452 kcal/mol. For the long-range electrostatic interactions, the particle− particle particle−mesh (PPPM) method has been used since it is found to give good agreement with the experimental results (Daub et al, 2011).…”

“…In the MD simulations, the wettability of a surface is controlled by varying the L-J interaction parameters between water and surface atoms. A lower L-J interaction will simulate a non-wetting surface, while a higher value will mimic the hydrophilic behavior of the surface . Therefore, the L-J parameter values considered for simulating the two surfaces are ε CuO = 0.3 kcal/mol (for surface A) and ε CuO = 1.452 kcal/mol.…”

A Wave‐Driven Piezoelectric Solar Evaporator for Water Purification

“…Uniform and alternating electric fields have been found to improve water evaporation in previous studies. [ 33–36 ] Unfortunately, the direct application of electricity to facilitate water evaporation cannot be regarded as an equivalent substitute for hydrogels because of its high cost and violation of the intention of green and sustainable development. Notably, oceans include various energy resources, such as tidal energy, wave energy, and ocean current energy.…”

Low‐dose liquid cell electron microscopy investigation of the complex etching mechanism of rod‐shaped silica colloids

“…[ 51 ] Finally we used the information obtained to explore the chemical composition of newly developed, even more complexly structured silica rod‐shaped particles known as crooked silica rods. Such crooked rods have been developed recently in our group [ 52 ] and that of others [ 53 ] as such particles can form interesting new colloidal liquid crystal phases. [ 54 ]…”