Síntese sol-gel de novos materiais com alta capacidade de captura de água

Abstract

Techniques based on different forms of water-solid interaction, such as adsorption and deliquescence, present interesting chemical or physical interactions to solve or minimize problems in which moisture is undesirable. In fact, these properties can be used in the development of new materials with high water capture capacity. The mesoporous adsorbents and the deliquescent materials have significant abilities to capture water, in addition to present simple preparation methods. In this work, two methodologies were developed for the synthesis of new materials with high water uptake capacity. The materials produced were mesoporous silica adsorbents and deliquescent calcium phosphate (CaP) materials. The prepared materials were characterized using techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen sorption, thermogravimetry (TG), differential exploratory calorimetry (DSC) and scanning electron microscopy (MEV). The water capture capacity of the developed materials was evaluated using a climatic chamber with controlled temperature and humidity. The results proved different types of interaction and satisfactory performance about the water capture of the developed materials in relation to a commercial silica sample, material used as reference in the experiments. This study brings an alternative approach to those reported in several works, where complex and multi-step procedures are used to obtain materials for water capture applications or the removal of other contaminants. Furthermore, both adsorbent and deliquescent samples were prepared here without addition of acidic or basic catalysts. The absence of these reagents represents an important advantage in terms of safety and environmental sustainability.