Atmospheric water harvesting using functionalized carbon nanocones

Abstract

In this work, we propose a method to harvest liquid water from water vapor using carbon nanocones. The condensation occurs due to the presence of hydrophilic sites at the nanocone entrance. The functionalization, together with the high mobility of water inside nanostructures, leads to a fast water flow through the nanostructure. We show using molecular dynamics simulations that this device is able to collect water if the surface functionalization is properly selected.

Thermodynamics and hydrodynamics of spontaneous and forced imbibition in conical capillaries: A theoretical study of conical liquid diode

“…The critical angles of the diverging capillaries are θ c(D) = 80 • and 60 • , respectively, from Eq. (23). Spontaneous imbibition is possible when the scaled pressure is positive.…”

“…In particular, truncated conical capillaries have been extensively studied as the simplest model to study the effect of geometrical gradient and, in particular, as the model of imbibition into porous substrates 5 . Also, they have been studied for their potential applications as micro-and nano-fluidic devices 12,16,[18][19][20][21][22][23] such as liquid diode 12,16,20,21 , ionic current rectifier 18 , pump 19 , Janus paper 22 , and water harvesting 23 . Carbon nanocone seems the most promising candidate of conical nano capillaries 23,24 .…”

“…Also, they have been studied for their potential applications as micro-and nano-fluidic devices 12,16,[18][19][20][21][22][23] such as liquid diode 12,16,20,21 , ionic current rectifier 18 , pump 19 , Janus paper 22 , and water harvesting 23 . Carbon nanocone seems the most promising candidate of conical nano capillaries 23,24 . Those capillaries in Fig.…”

“…Although a large amount of literature on double conical capillaries has already been accumulated 5,[7][8][9][11][12][13] , most of the theoretical works studied transport properties numerically using macroscopic fluid dynamic equations [17][18][19][20]27,32,33 or atomic molecular dynamic simulations 23,24,28,29 which are limited to sub nano-scale. Relatively few studies based on thermodynamics have been conducted to understand the quasi-static imbibition processes 4,21,[35][36][37][38][39] .…”

“…(22). The critical angles of the diverging capillaries are θ c(D) = 80 • and 60 • , respectively, from Eq (23)…”