Effect of molecular structure on the adsorption affinity of sulfonamides onto CNTs: Batch experiments and DFT calculations. (May 2020)

• Record Type: Journal Article
• Authors: Liu, Yunbo; Peng, Yunlan; An, Baohua; Li, Laicai; Liu, Yong
• Is Part Of: Chemosphere. Volume 246(2020)
• Publication Date: 2020-05
• Subjects: Carbon nanotubes -- Antibiotics -- Adsorptive affinity -- Density functional theory -- Molecular structure -- Activity relationship; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.125778
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In order to investigate the adsorption behaviors of sulfonamides onto hydroxylated multi - walled carbon nanotubes (CNTs) with a porous structure and large specific surface area, six typical sulfonamides including sulfanilamide (SAM), sulfamerazine (SMR), sulfadimethoxine (SMX), sulfadiazine (SDZ), sulfamethazine (SMT) and sulfametoxydiazine (SMD) were selected to be adsorbed respectively on CNTs, and in the same time the structural parameters of the six sulfonamides molecules were calculated according to the density functional theory (DFT). Based upon above mentioned experiments and the structural parameters, the quantitative correlation between the structural parameters of sulfonamides molecules and their adsorption affinity (e.g. adsorption capacity and adsorption rate constant) onto CNTs was established, respectively. The adsorption data of sulfonamides fitted well with the pseudo - second - order kinetic model and the Langmuir isotherm model. The order of both pseudo - second - order kinetic constant and maximum adsorption capacity of the six sulfonamides were SAM < SMR < SMX < SDZ < SMT < SMD. The frontier molecular orbital energy (EHOMO ) and dipole moment (μ) could be used as indicators for the adsorption affinity of sulfonamides onto CNTs. Accordingly, the possible adsorption mechanism was proposed. Graphical abstract: Image 1 Highlights: Adsorption behaviors of six sulfonamides molecules onto CNTs were investigated. Molecular structure was found to be critical in the adsorption of sulfonamides onto CNTs. The quantitative correlation between sulfonamides structural parameters and CNTs adsorption performance were established.