Nanocomposite based on Multi-Macrocyclic Receptors and Halloysite for Volatile Organic Compounds Capture

Abstract

Volatile organic compounds (VOCs) are chemicals released to the atmosphere by natural and anthropogenic sources. VOCs are hazardous air pollutants and promote formation of photochemical smog. Variety of chemicals released from pharmaceutical industry includes priority pollutants like benzene, toluene, and dichloromethane. The aim of this work was at designing, preparing and characterizing from the physico-chemical view-point a pseudo nano-sponge with low environmental impact for pollutant removal. As adsorbent material, a nanocomposite based on nanoclay and cucurbiturils, which are biocompatible materials, were investigated. Clay minerals (e.g. montmorillonite and kaolin) are important components of soils and sediments. Many have strong sorption affinities, large specific surface areas and high cation exchange capacities. These aluminosilicates have been tested since more than 40 years ago in the removal of toxic metals or organic pollutants. Among the aluminosilicates, halloysite (Al2Si2O5(OH)4 ·nH2O) is a special nano-geomaterial because of its tubular morphology, high porosity and tunable surface chemistry which enabled it to be utilized as a promising adsorbent for various organic pollutants. Cucurbiturils are cyclic polymers of glycourils which can exhibit similar host–guest chemistry as cyclodextrins. There are different homologues of cucurbiturils among which CB[8] selected in this work can hold small gas molecules, aliphatic and aromatic guests. The adsorption capability of hybrid nano-sponge was investigated and correlated to the structural feature of the adsorbent sustainable nanomaterial. Toluene was selected as contaminant prototype