Compósitos à base de polímeros e zeólitas para adsorção e fotodegradação de compostos orgânicos voláteis

Abstract

Volatile Organic Compounds (VOCs) are among the principal air pollutants, giving the environment and human health several problems due to its high toxicity. Adsorption and photodegradation are widely used in the removal of VOCs from the air since they are high efficiency and low-cost processes. The use of polymer films incorporated with zeolite-TiO2 composites associated with UV radiation is an alternative in the removal of these pollutants through adsorption and photodegradation processes. The present study aims to produce PLA (Poly(lactic acid)) films incorporated with zeolite 13X, TiO2 and zeolite 13X-TiO2 composite (ZT) by the solvent casting technique, to remove n-butanol (VOC model molecule) from the air. Therefore, films were prepared using zeolite (8%), TiO2 (2%) and composite ZT in different percentages (0, 5, 10, and 25%) added to the PLA matrix. The results showed that Zeolite 13X and TiO2 added individually or in a composite form in PLA give the polymer matrix an increase in the removal capacity of n-butanol, with a better performance of the ZT composite than the individual fillers, suggesting a synergistic effect. The photodegradation tests of n-butanol resulted in the formation of CO, CO2, and several oxygenated organic byproducts, with butanal as the most significant intermediate formed. The presence of the zeolite 13X seems to inhibit the formation of undesirable by-products and contribute to the removal of n-butanol, indicating its application in the removal of VOCs in the indoor air environments, with a lower risk of photodegradation of the polymer matrix observed in the films containing TiO2.