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

Abstract

The differences in effectiveness of multi-walled 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-HCNT and I(1,2,3-cd)P-HCNT are substantially less negative than those observed for PAH molecules interacting with the non-helical 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 PAH-HCNT 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.Electronic supplementary materialThe online version of this article (10.1007/s11270-018-3884-0) contains supplementary material, which is available to authorized users.

Synthesis of Poly(methacrylic acid-co-butyl acrylate) Grafted onto Functionalized Carbon Nanotube Nanocomposites for Drug Delivery

“…Nonetheless, in this work, we use a different experimental approach to achieve the HMWCNTs’ synthesis, regarding a previously reported approach [ 36 ]. HMWCNTs have interesting properties; for example, they can act as an efficient material for the dispersive solid-phase extraction of low and high molecular weight polycyclic aromatic hydrocarbons, from aqueous solutions [ 37 ]. In this work, we report the use of synthesized HMWCNTs to prepare CNTs o-OCl-MAA –BA and CNTs r-OCl-MAA –BA PNs nanocomposites.…”

Adsorption of Pyrene and Arsenite by Micro/Nano Carbon Black and Iron Oxide

“…Previous studies have shown that the adsorption mechanisms of carbon materials on PAHs included hydrophobic interactions, van der Waals forces, and π bond interactions [ 12 , 20 , 21 ]. Micro/nano carbon black has a large specific surface area, and its surface hydrophobicity could create favorable conditions for the adsorption of pyrene [ 22 ].…”

Recent Materials Developed for Dispersive Solid Phase Extraction

“…CNTs show good thermal and chemical stability, which, combined with their high adsorption capacity, ability to enter into π-π interactions with aromatic compounds as well as the relative ease with which they can be modified, opens up exciting possibilities for their application. While they have already found wide use in other separation techniques, such as standard SPE or SBSE, only recently have carbon nanotubes begun to gain popularity as sorbents in dSPE procedures [ 4 , 47 , 48 ]. A series of works published by Paszkiewicz et al describe the performance of several MWCNT types as dSPE sorbents in analytical procedures determining different analytes, including PAHs [ 4 , 47 ], heavy metals [ 4 ] and various pharmaceuticals [ 48 , 49 ].…”