Gas phase adsorption of water and methanol onto engineered nanomaterials: silicon dioxide nanopowder, carbon60 fullerene, single wall carbon nanotubes

Engineered nanomaterials may undergo atmospheric transformations when they interact with water vapor or hazardous air pollutants (HAPs). Water vapor or HAPs may adsorb onto engineered nanoparticles. This creates a problem because biological systems may then uptake engineered nanomaterials that contain sorbed pollutants. Therefore, it is important to quantify the amount of water and HAPs that may adsorb onto and desorb from engineered nanoparticles. The present study investigates the gas phase adsorption and desorption of water and methanol at atmospheric conditions (25°C and 1 atm) onto industrially produced engineered nanomaterials commonly found in consumer nanoproducts (SiO 2 nanopowder, C60 fullerene, and single wall carbon nanotubes). A new mathematical model, the weighted and combined Frenkel, Halsey, and Hill (FHH) -- Langmuir, is proposed to better predict the adsorption capacities of HAPs onto engineered nanomaterials. The morphology and surface area of the nanomaterials, as well as the adsorption and desorption kinetic rate constants of water and methanol onto the engineered nanomaterials were determined.