Phenol Molecular Sheets Woven by Water Cavities in Hydrophobic Slit Nanospaces

Abstract

Despite extensive research over the last several decades, the microscopic characterization of topological phases of adsorbed phenol from aqueous solutions in carbon micropores (pore size < 2.0 nm), which are believed to exhibit a solid and quasi-solid character, has not been reported. Here, we present a combined experimental and molecular level study of phenol adsorption from neutral water solutions in graphitic carbon micropores. Theoretical and experimental results show high adsorption of phenol and negligible coadsorption of water in hydrophobic graphitic micropores (super-sieving effect). Graphic processing unit-accelerated molecular dynamics simulation of phenol adsorption from water solutions in a realistic model of carbon micropores reveal the formation of two-dimensional phenol crystals with a peculiar pattern of hydrophilic–hydrophobic stripes in 0.8 nm supermicropores. In wider micropores, disordered phenol assemblies with water clusters, linear chains, and cavities of various sizes are found. The highest surface density of phenol is computed in 1.8 nm supermicropores. The percolating water cluster spanning the entire pore space is found in 2.0 nm supermicropores. Our findings open the door for the design of better materials for purification of aqueous solutions from nonelectrolyte micropollution.

Investigation of Effects of Acid, Alkali, and Salt Solutions on Fluorinated Superhydrophobic Surfaces

“…4 In recent years, superhydrophobic surfaces have drawn great attention in theoretical research and potentials in practice. 5,6 It has been reported that the superhydrophobic surfaces present unique properties, such as self-cleaning, oil−water separation, antibacteria, drag reduction, luminescent solar concentrators, and corrosion resistance. 7−15 However, superhydrophobic surfaces can be easily destroyed under extreme environments such as acid rain and etchant solutions, leading to limited applications in industry, especially anticorrosive fields, because of their poor stability of superhydrophobic coating.…”

“…Under further investigation, their superior performance of functional surface is attributed to the typical superhydrophobic characteristic with water contact angles (WCAs) of more than 150° and rolling angles less than 10° . In recent years, superhydrophobic surfaces have drawn great attention in theoretical research and potentials in practice. , It has been reported that the superhydrophobic surfaces present unique properties, such as self-cleaning, oil–water separation, antibacteria, drag reduction, luminescent solar concentrators, and corrosion resistance. − However, superhydrophobic surfaces can be easily destroyed under extreme environments such as acid rain and etchant solutions, leading to limited applications in industry, especially anticorrosive fields, because of their poor stability of superhydrophobic coating. It is therefore urgent to explore the corrosion mechanism or protection mechanism when such surfaces are immersed into various corrosive media .…”