Novel Inorganic Membranes Based on Magnetite-Containing Silica Porous Glasses for Ultrafiltration: Structure and Sorption Properties

• Published in: Membranes (Basel) 2023-03, Vol.13 (3), p.341
• Main Authors: Konon, Marina, Brazovskaya, Elena Yu, Kreisberg, Valery, Semenova, Ekaterina, Polyakova, Irina G, Osipov, Armenak, Antropova, Tatiana
• Format: Article
• Language: English
• Subjects: Accuracy; Adsorbents; Adsorption; Analysis; Aqueous solutions; Borosilicate glass; Composite materials; Crystallization; Desalination; Energy conservation; Environmental impact; Ferric oxide; Heat; inorganic membranes; Iron; Kinetics; Leaching; Magnetic properties; Magnetite; Membrane separation; Membranes; Methylene blue; Netherlands; Particle diffusion; phase-separated glass; Pore size; porous glass; Purification; Radiation; Raman spectroscopy; Russia; Sewage; Silica; Silica glass; Silicon dioxide; Sorption; Specific surface; Surface area; Surface properties; Ultrafiltration; Water treatment
• ISSN: 2077-0375; 2077-0375
• DOI: 10.3390/membranes13030341

Porous glasses (PGs) obtained from sodium borosilicate (NBS) phase-separated glasses via leaching are promising inorganic membranes. Introducing Fe O into NBS glasses imparts ferrimagnetic properties due to magnetite crystallization. Leaching of such glasses leads to the formation of magnetic PGs with interesting electro-surface characteristics. This work aimed to investigate the process of obtaining magnetite-containing PGs from NBS glasses depending on silica content, using XRPD and Raman spectroscopy, studying the PG membranes' structural characteristics and their sorption properties with respect to methylene blue (MB). Obtained PGs were characterized by a polymodal distribution of mesopores and a small number of micropores with specific surface area values of 32-135 m /g and an average mesopore diameter of 5-41 nm. The kinetic data were analyzed using pseudo-first-order, pseudo-second-order, and intra-particle diffusion equations. The equilibrium isotherms were fitted with Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models. MB adsorption was found to be a complex process. The glass with the highest specific surface area demonstrated the maximum sorption capacity (10.5 mg/g). The pore size of PGs allowed them to be considered potential novel magnetic membranes for ultrafiltration.