Vipin Adavan Kiliyankil, Fugetsu Bunshi, Sakata Ichiro, Isogai Akira, Endo Morinobu, Li Mingda, Dresselhaus Mildred S
School of Engineering, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-8656, Japan.
Policy Alternatives Research Institute, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-0033, Japan.
Sci Rep. 2016 Nov 15;6:37009. doi: 10.1038/srep37009.
On 11 March 2011, the day of the unforgettable disaster of the 9 magnitude Tohoku earthquake and quickly followed by the devastating Tsunami, a damageable amount of radionuclides had dispersed from the Fukushima Daiichi's damaged nuclear reactors. Decontamination of the dispersed radionuclides from seawater and soil, due to the huge amounts of coexisting ions with competitive functionalities, has been the topmost difficulty. Ferric hexacyanoferrate, also known as Prussian blue (PB), has been the most powerful material for selectively trapping the radioactive cesium ions; its high tendency to form stable colloids in water, however, has made PB to be impossible for the open-field radioactive cesium decontamination applications. A nano/nano combinatorial approach, as is described in this study, has provided an ultimate solution to this intrinsic colloid formation difficulty of PB. Cellulose nanofibers (CNF) were used to immobilize PB via the creation of CNF-backboned PB. The CNF-backboned PB (CNF/PB) was found to be highly tolerant to water and moreover, it gave a 139 mg/g capability and a million (10) order of magnitude distribution coefficient (K) for absorbing of the radioactive cesium ion. Field studies on soil and seawater decontaminations in Fukushima gave satisfactory results, demonstrating high capabilities of CNF/PB for practical applications.
2011年3月11日，在发生令人难忘的9级东北地震并随后很快引发毁灭性海啸的当天，福岛第一核电站受损核反应堆中有大量放射性核素泄漏。由于海水中和土壤中存在大量具有竞争功能的共存离子，去除这些分散的放射性核素极具难度。六氰合铁酸铁，也就是普鲁士蓝（PB），是选择性捕获放射性铯离子的最有效材料；然而，它在水中极易形成稳定胶体，这使得PB无法用于野外放射性铯污染的净化。正如本研究中所描述的，一种纳米/纳米组合方法为解决PB这种内在的胶体形成难题提供了最终方案。通过创建以纤维素纳米纤维（CNF）为骨架的PB，利用纤维素纳米纤维来固定PB。结果发现，以CNF为骨架的PB（CNF/PB）具有很强的耐水性，此外，它对放射性铯离子的吸收能力为139 mg/g，分配系数（K）达到百万（10）数量级。在福岛进行的土壤和海水净化现场研究取得了令人满意的结果，证明了CNF/PB在实际应用中的卓越性能。
