Effects of acidification time of MWCNTs on carbon dioxide capture of liquid-like MWCNTs organic hybrid materials

Abstract

In this study, liquid-like multi-walled carbon nanotubes (MWCNTs) nanoparticle organic hybrid materials (MWCNTs-NOHMs) were prepared without solvent at room temperature (25 °C) by employing MWCNTs with different acidification times as the core, KH560 as the corona and M2070 as the canopy. The acidification time of MWCNTs on CO₂ capture capacity of the MWCNTs-NOHMs was investigated. The number of amine groups on the surface of the MWCNTs-NOHMs increased with the prolongation of acidification time. The CO₂ capture capacity of the MWCNTs-NOHMs decreased with the extension of the acidification time for the MWCNTs. This is due to the superior fluidity and poorer viscosity of the MWCNTs-NOHM left in acid for a shorter time period. The superior fluidity and poorer viscosity provided larger molecule intervals and weaker intermolecular forces, making it easier for CO₂ to charge into the potential space. CO₂ can react with amine groups. However, because of the low fluidity and the high viscosity of the MWCNTs-NOHM left in acid for a longer time, its physisorption was unsatisfactory. Chemisorption was also influenced via reducing the contact between CO₂ and the reactive groups. The regeneration capacity and adsorption stability of the MWCNTs-NOHMs are great, rendering them as potential materials for CO₂ adsorption.