Helical multi-walled carbon nanotubes as an efficient material for the dispersive solid-phase extraction of low and high molecular weight polycyclic aromatic hydrocarbons from water samples: theoretical study
Monika Paszkiewicz , Celina Sikorska , Danuta Leszczyńska , Piotr Stepnowski
AbstractThe differences in effectiveness of multiwalled carbon nanotubes (MWCNTs) as the dispersive solid-phase extraction (dSPE) sorbent for the selective extraction of polycyclic aromatic hydrocarbons (PAHs) were explained on the basis of theoretical study. It was observed that for low molecular weight PAHs, the recoveries using non-helical and helical MWCNTs were similar. In contrary, for PAHs containing five or more aromatic rings, the extraction efficiency was higher using HMWCNTs than for non-helical ones. Principle component analysis (PCA) as well as providing structural parameters and interaction energies for adsorption processes (PAH + CNT → PAH-CNT) have been used for this purpose. All the PAH + CNT→PAH-CNT adsorption processes considered were found to be thermodynamically favorable. However, the adsorption energies (Eads) for PAHs and the helical carbon nanotube surface estimated for the B(a)P-HCNTand I(1,2,3-cd)PHCNT are substantially less negative than those observed for PAH molecules interacting with the nonhelical CNT. Namely, the Eads calculated in simulated aqueous environment for the B(a)P-MWCNT(6,2) and I(1,2,3-cd)P-MWCNT(6,2) were respectively − 43.32 and − 59.98 kcal/mol, while values of only − 7.75 kcal/mol (B(a)P-HCNT) and − 9.13 kcal/mol (I(1,2,3-cd)P-HCNT) were found for the corresponding PAH-HCNT systems. Therefore, we conclude that the replacement of MWCNTs with HCNTs leads to PAHHCNT systems in which the interaction energies are much smaller than those estimated for the corresponding PAH-MWCNT systems. HMWCNTs are therefore recommended as the dSPE sorbent phase for the extraction of both low and high molecular weight PAHs from water samples.
|Journal series||Water Air and Soil Pollution, ISSN 0049-6979, (A 25 pkt)|
|Publication size in sheets||0.7|
|Keywords in English||multi-walled carbon nanotubes (MWCNTs), adsorption, dispersive solid-phase extraction (dSPE), principle component analysis (PCA), polycyclic aromatic hydrocarbons (PAHs), molecular modeling, analytical chemistry, polarizable continuum model (PCM)|
|License||Other; published final; ; with publication|
|Score|| = 25.0, ArticleFromJournal|
= 25.0, ArticleFromJournal
|Publication indicators||= 0; = 0; : 2017 = 1.769 (2) - 2017=1.972 (5)|
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