Adsorption of perfluoroalkyl substances on bridged functionalized organosilica materials
Abstract
Per- and polyfluoroalkyl substances (PFAS) are man-made molecules with extremely stable carbon-fluorine bonds. They persist in the environment, causing significant health problems in humans and animals through contamination of water, soil, and food. Existing adsorption methods for removing PFAS from water sources have limitations, including high production and regeneration costs, low removal efficiencies, and long processing times. The objective of this study was to address these limitations by creating a cost-effective bridged organosilica material for the removal of PFAS from contaminated water. The material was prepared by a sol-gel process from bis[3 (trimethoxysilyl)propyl]amine without the addition of surfactants, bases, or acids. The organosilica surface was subsequently modified by protonating the amine groups to create positively charged adsorption sites. These sites can electrostatically interact with the negatively charged anions of PFAS molecules, enhancing the material's ability to adsorb them. The adsorption capacity of the materials was evaluated using ammonium and potassium salts of perfluorooctanesulfonic, perfluorobutanesulfonic and perfluorooctanoic acids. Chemical and instrumental analysis demonstrated the exceptional ability of the materials to remove PFAS. Thermal analysis confirmed the stability of the modified organosilica against degradation at temperatures up to 150°C. Column experiments with the modified material revealed two distinct types of adsorption sites on its surface. An aqueous sodium hydroxide solution proved to be a suitable medium for regenerating spent modified organosilica. The study results demonstrate that the modified bridged organosilica represents a cost-effective and promising solution for combating PFAS contamination of water sources.
Start Time
15-4-2026 10:00 AM
End Time
15-4-2026 11:00 AM
Room Number
303
Presentation Type
Oral Presentation
Presentation Subtype
Grad/Comp Orals
Presentation Category
Science, Technology, and Engineering
Student Type
Graduate
Faculty Mentor
Aleksey Vasiliev
Adsorption of perfluoroalkyl substances on bridged functionalized organosilica materials
303
Per- and polyfluoroalkyl substances (PFAS) are man-made molecules with extremely stable carbon-fluorine bonds. They persist in the environment, causing significant health problems in humans and animals through contamination of water, soil, and food. Existing adsorption methods for removing PFAS from water sources have limitations, including high production and regeneration costs, low removal efficiencies, and long processing times. The objective of this study was to address these limitations by creating a cost-effective bridged organosilica material for the removal of PFAS from contaminated water. The material was prepared by a sol-gel process from bis[3 (trimethoxysilyl)propyl]amine without the addition of surfactants, bases, or acids. The organosilica surface was subsequently modified by protonating the amine groups to create positively charged adsorption sites. These sites can electrostatically interact with the negatively charged anions of PFAS molecules, enhancing the material's ability to adsorb them. The adsorption capacity of the materials was evaluated using ammonium and potassium salts of perfluorooctanesulfonic, perfluorobutanesulfonic and perfluorooctanoic acids. Chemical and instrumental analysis demonstrated the exceptional ability of the materials to remove PFAS. Thermal analysis confirmed the stability of the modified organosilica against degradation at temperatures up to 150°C. Column experiments with the modified material revealed two distinct types of adsorption sites on its surface. An aqueous sodium hydroxide solution proved to be a suitable medium for regenerating spent modified organosilica. The study results demonstrate that the modified bridged organosilica represents a cost-effective and promising solution for combating PFAS contamination of water sources.
