Influence of the aromatic surface on the capacity of adsorption of VOCs by magnetite supported organic-inorganic hybrids.

María De Las Nieves Piña,María Susana Gutiérrez,Mario Panagos,David Quiñonero,Paulino Duel,Antonio Frontera,Alberto León,Jeroni Morey

doi:10.1039/c9ra04490f

María De Las Nieves Piña, María Susana Gutiérrez + Show 6 more

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https://doi.org/10.1039/c9ra04490f

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Abstract

It has been recently evidenced that hybrid magnetic nanomaterials based on perylene diimide (PDI) dopamine and iron oxide nanoparticles are useful for the adsorption and determination of volatile organic compounds (VOCs). However, NDI compounds are expensive and difficult to handle compared to smaller size diimides. Therefore, in this manuscript a combined experimental and theoretical investigation is reported including the analysis of the effect of changing the aromatic surface on the ability of these magnetite supported organic–inorganic hybrid nanoparticles (NPs) to adsorb several aromatic and non-aromatic VOCs. In particular, two new hybrid Fe3O4NPs are synthesized and characterized where the size of organic PDI dopamine linker is progressively reduced to naphthalene diimide (NDI) and pyromellitic diimide (PMDI). These materials were utilized to fill two sorbent tubes in series. Thermal desorption (TD) combined with capillary gas chromatography (GC)/flame detector (FID) was used to analyze both front and back tubes. Adsorption values (defined as % VOCs found in the front tube) were determined for a series of VOCs. The binding energies (DFT-D3 calculations) of VOC–Fe3O4NP complexes were also computed to correlate the electron-accepting ability of the arylene diimide (PDI, NDI or PMDI) with the adsorption capacity of the different tubes. The prepared hybrids can be easily separated magnetically and showed great reusability.

Highlights

Volatile organic compounds (VOCs) are inherent to modern human life
It can be observed that the MEP values are more positive at the imidic rings varying from +79 for naphthalene diimide (NDI) and pyromellitic diimide (PMDI) to +54 kJ molÀ1 for perylene diimide (PDI)
For the aliphatic VOC, it is expected that the p-acidic surface will have affinity for the negative O atoms, it is possible to envisage C–H/O interactions since the MEP surfaces of PDI, NDI and PMDI molecules exhibit positive values in the molecular plane close to the C–H bonds

Summary

Introduction

Volatile organic compounds (VOCs) are inherent to modern human life. They are used as markers in medicine[1] and industry.[2] they are used as indicators for the presence of other substances. The investigation of VOCs is intensive in many areas like environmental research,[3] medicine,[4] and even in military applications.[5] The analysis and quanti cation of VOCs is needed to control the quality of biomaterials[6] and they are used as markers of microbial contamination in the case of bacteria and fungi.[7] VOCs are normally used as markers in food industry for controlling the quality of raw materials.[8]

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