Multiwall carbon nanotubes (MWCNTs) have been used as an adsorbent for evaluating the gas/solid partitioning of selected volatile organic compounds (VOCs). In this study, 15 VOCs were probed to determine their gas/solid partitioning coefficient (LogK(d)) using inverse gas chromatography at different relative humidity (RH) levels. Interactions between MWCNTs and VOCs were analyzed by regressing the observed LogK(d) with the linear solvation energy relationship (LSER). The results demonstrate that the MWCNT carbonyl and carboxyl groups provide high adsorption capacity for the VOCs (LogK(d) 3.72-5.24g/kg/g/L) because of the pi-/n-electron pair interactions and hydrogen-bond acidity. The increasing RH gradually decreased the Log K-d and shifted the interactions to dipolarity/polarizability, hydrogen-bond basicity, and cavity formation. The derived LSER equations provided adequate fits of LogK(d), which is useful for VOC-removal processes and fate prediction of VOC contaminants by MWCNT adsorption in the environment. (C) 2016 Elsevier B.V. All rights reserved.