Microporous materials for the selective adsorption of perfluorinated surfactants

Perfluorinated alkylated substances (PFASs) are a class of persistent organic pollutants that are widely used for the production of many fluoropolymers, besides from a wide range of other applications. Due to their toxicity and widespread occurrence in (drinking) water, food products and humans, the EU recently introduced environmental quality standards for the concentrations of the most relevant PFCs in natural waters. Currently, there are no practical treatment techniques available that lower the concentrations of these compounds for large water bodies in a cost- and energy-efficient way. In this PhD, a hydrophobic, all-silica zeolite Beta material that is a highly selective and high-capacity adsorbent for PFASs, even in the presence of organic competitors, is proposed. Summarizing, the PFAS molecules are positioned in the straight channels of the zeolite, with the hydrophobic chains in the channels and the carboxylic heads, forming hydrogen bonded pairs, in the intersections. This results in a very favorable adsorption enthalpy and a very tight packing at maximal capacity, explaining the exceptionally high affinity and selectivity of all-silica zeolite Beta for PFOA and similar perfluorinated compounds. These properties position this unusual zeolite as the lead candidate for combating PFAS pollution.

Jaar van publicatie:2021

Toegankelijkheid:Open