Cationic hydrogels from a positively charged monomer, (3-Acrylamidopropyl)-trimethylammonium chloride (APTMACl), were synthesized as bulk, and micro- and nano-sizes. These hydrogels were utilized to remove contaminants such as food dyes and an environmentally toxic metal, arsenic. The micro- and nanohydrogels were dispersed in another hydrogel network to design a semi-interpenetrating network (semi-IPN) which was shown to visualize the particles that can be used for absorption purposes. The micron-sized cationic hydrogel particles were very effective in the removal of arsenic from an aqueous environment- 96% of the arsenic was removed in less than 10 min from a 55-ppm aqueous stock solution. Cationic hydrogels ca. 5 nm were also prepared and demonstrated for fluorescein dye absorption in the nanohydrogel-hydrogel semi-IPN. Hydrogel particle sizes were investigated with microscopic methods, such as optical, fluorescence, scanning electron and transmission electron microcopes.
SAHINER, NURETTIN (2008) "Hydrogels of Versatile Size and Architecture for Effective Environmental Applications," Turkish Journal of Chemistry: Vol. 32: No. 1, Article 11. Available at: https://journals.tubitak.gov.tr/chem/vol32/iss1/11