Modeling adsorption of organic compounds (OCs) by carbon nanotubes (CNTs): role of OCs and CNTs properties on the linear solvation energy relationships (LSER)

This study evaluated a comprehensive database for the adsorption of polar and nonpolar organic compounds (OCs) by carbon nanotubes (CNTs) and to use the linear solvation energy relationship (LSER) technique for developing predictive adsorption models of OCs by multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs). The results showed that coefficient of determinations (R-2) values for all compounds are higher variability in the 200 g/mol molecular weight cutoff (74-99%). When the molecular weight cutoff of all OCs is higher than 200 g/mol, the trend of their R-2 values is decreased (less than 70%). Among all adsorbate descriptor coefficients, V and B terms are the most significant descriptors (p values <= 0.05) in LSER equations for adsorption of low molecular weight polar and nonpolar OCs by both CNTs. Besides, K-OW normalization of all K-d values did not have significant impact on the regression of the LSER model, indicating that hydrophobic interactions are not sole mechanism for the adsorption of OCs on CNTs. Lastly, SWCNTs exhibited higher polar OCs uptake than MWCNTs, which was attributed to more polar surface of SWCNTs as suggested by its high oxygen content (%10).

Automated summary

The study evaluated the adsorption of polar and nonpolar organic compounds by carbon nanotubes and developed predictive adsorption models using the LSER technique. Results showed variability in R-2 values for all compounds at the 200 g/mol molecular weight cutoff. The V and B terms were found to be significant descriptors in the LSER equations for adsorption of OCs.