Used as an ion-exchange material in water treatment and nuclear reactors due to its high thermal and radiation stability. Effective in removing heavy metal ions and radioactive isotopes from aqueous solutions. Also applied in catalysis, particularly in acid-catalyzed reactions, owing to its strong Bronsted acidity. Serves as a flame retardant additive in polymers and coatings. Utilized in the development of proton-conducting membranes for fuel cells because of its ability to conduct protons under humid conditions. Shows promise in drug delivery systems and biomedical applications due to its biocompatibility and controlled release properties.