Separation of chloroform from a dilute solution using a cyclic peptide nanotube: A molecular dynamics study

This work firstly explored the potential application of a cyclic peptide nanotube (CPNT) in the separation of chloroform from a dilute solution. Four hydrophobic CPNTs of 8 x (W (L) under bar)(4.5) and 8 x (A (L) under bar)(4.5) all exhibit excellent adsorption characteristics to chloroform. The CPNT diameter, side chain structures and the concentration of chloroform in a solution all affect the adsorption characteristics of chloroform. CHCI3 molecules are overwhelmingly adsorbed on the surfaces of these CPNTs as a cluster, and sporadically reside inside the channels, consistent with the chloroform's potentials of mean force (PMFs) inside and outside the channels. The distribution characteristics, molecular orientations and interactions with the surroundings of chloroform inside and outside four CPNTs embedded in individual dilute CHCI3/water solutions were analyzed in detail, providing referable information of the adsorption characteristics of a hydrophobic CPNT to chloroform. (C) 2018 Elsevier Inc. All rights reserved.