논문 해외 국제전문학술지(SCI급) Nanocrystalline Low-Silica X Zeolite as an Efficient Ion-exchanger Enabling Fast Radioactive Strontium Capture
- 학술지 구분 국제전문학술지(SCI급)
- 게재년월 2024-07
- 저자명 Jeon, H., Lee, S., Kim, J.-C., and Choi, M*
- 학술지명 Frontiers of Chemical Science and Engineering
- 발행처명 Springer
- 발행국가 해외
- 논문언어 외국어
- 전체저자수 4
- 원문 링크 https://link.springer.com/article/10.1007/s11705-024-2449-6
홈페이지논문 초록 (Abstract)
NaA zeolite (Si/Al = 1.00) has been commercially applied for capturing radioactive 90Sr2+ because of its high surface charge density, effectively stabilizing the multivalent cation. However, owing to its narrow micropore opening (4.0 Å), large micron-sized crystallites, and bulkiness of hydrated Sr2+, the Sr2+ exchange over NaA has been limited by very slow kinetics. In this study, we synthesized nanocrystalline low-silica X by minimizing a water content in a synthesis gel and utilizing a methyl cellulose hydrogel as a crystal growth inhibitor. The resulting zeolite exhibited high crystallinity and Al-rich framework (Si/Al of approximately 1.00) with the sole presence of tetrahedral Al sites, which are capable of high Sr2+ uptake and ion selectivity. Meanwhile, the zeolite with a FAU topology has a much larger micropore opening size (7.4 Å) and a much smaller crystallite size (∼340 nm) than NaA, which enable significantly enhanced ionexchange kinetics. Compared to conventional NaA, the nanocrystalline low-silica X exhibited remarkably increased Sr2+-exchange kinetics (> 18-fold larger rate constant) in batch experiments. Although both the nanocrystalline low-silica X and NaA exhibited comparable Sr2+ capacities under equilibrated conditions, the former demonstrated a 5.5-fold larger breakthrough volume than NaA under dynamic conditions, attributed to its significantly faster Sr2+-exchange kinetics.