Mechanisms responsible for adsorption of molybdate ions on alumina for the production of medical radioisotopes

Fujita, Yoshitaka; Niizeki, Tomotake*; Fukumitsu, Nobuyoshi*; Ariga, Katsuhiko*; Yamauchi, Yusuke*; Malgras, V.*; Kaneti, Y. V.*; Liu, C.-H.*; Hatano, Kentaro*; Suematsu, Hisayuki*; et al.

Bulletin of the Chemical Society of Japan, 95(1), p.129 - 137, 2022/01

https://doi.org/10.1246/bcsj.20210249

In this work, the mechanisms responsible for the adsorption of molybdate ions on alumina are investigated using in-depth surface analyses carried out on alumina specimens immersed in solutions containing different molybdate ions at different pH values. The obtained results reveal that when alumina is immersed in an acidic solution containing molybdate ions, the hydroxyl groups present on the surface are removed to generate positively charged sites, and molybdate ions (MoO or AlMoOH) are adsorbed by electrostatic interaction. Alumina dissolves slightly in an acidic solution to form AlMoOH, which is more easily desorbed than MoO. Furthermore, the enhancement in the Mo adsorption or desorption property may be achieved by enriching the surface of the alumina adsorbent with many -OH groups and optimizing Mo solution to adsorb molybdate ions on alumina as MoO ions. These findings will assist researchers in engineering more efficient and stable alumina-based adsorbents for molybdenum adsorption used in medical radioisotope (Mo/Tc) generators.

Biomolecule-assisted synthesis of hierarchical multilayered boehmite and alumina nanosheets for enhanced molybdenum adsorption

Saptiama, I.*; Kaneti, Y. V.*; Yuliarto, B.*; Kumada, Hiroaki*; Tsuchiya, Kunihiko; Fujita, Yoshitaka; Malgras, V.*; Fukumitsu, Nobuyoshi*; Sakae, Takeji*; Hatano, Kentaro*; et al.

Chemistry; A European Journal, 25(18), p.4843 - 4855, 2019/03

https://doi.org/10.1002/chem.201900177

The effective utilization of various biomolecules for creating a series of mesoporous boehmite (-AlOOH) and gamma-alumina (-AlO) nanosheets with unique hierarchical multilayered structures is demonstrated. The nature and concentration of the biomolecules strongly influence the degree of the crystallinity, the morphology, and the textural properties of the resulting -AlOOH and -AlO nanosheets, allowing for easy tuning. The hierarchical -AlOOH and -AlO multilayered nanosheets synthesized by using biomolecules exhibit enhanced crystallinity, improved particle separation, and well-defined multilayered structures compared to those obtained without biomolecules. More impressively, these -AlOOH and -AlO nanosheets possess high surface areas up to 425 and 371 m/g, respectively, due to their mesoporous nature and hierarchical multilayered structure. When employed for molybdenum adsorption toward medical radioisotope production, the hierarchical -AlO multilayered nanosheets exhibit Mo adsorption capacities of 33.140.8mg-Mo/g.

Template-free fabrication of mesoporous alumina nanospheres using post-synthesis water-ethanol treatment of monodispersed aluminium glycerate nanospheres for molybdenum adsorption

Saptiama, I.*; Kaneti, Y. V.*; Suzuki, Yoshitaka; Tsuchiya, Kunihiko; Fukumitsu, Nobuyoshi*; Sakae, Takeji*; Kim, J.*; Kang, Y.-M.*; Ariga, Katsuhiko*; Yamauchi, Yusuke*

Small, 14(21), p.1800474_1 - 1800474_14, 2018/05

https://doi.org/10.1002/smll.201800474

no abstracts in English

Mesoporous alumina as an effective adsorbent for molybdenum (Mo) toward Instant production of radioisotope for medical use

Saptiama, I.*; Kaneti, Y. V.*; Suzuki, Yumi*; Suzuki, Yoshitaka; Tsuchiya, Kunihiko; Sakae, Takeji*; Takai, Kimiko*; Fukumitsu, Nobuyoshi*; Alothman, Z. A.*; Hossain, M. S. A.*; et al.

Bulletin of the Chemical Society of Japan, 90(10), p.1174 - 1179, 2017/10

https://doi.org/10.1246/bcsj.20170184

no abstracts in English

Mesoporous silica particles as topologically crosslinking fillers for poly(-isopropylacrylamide) hydrogels

Miyamoto, Nobuyoshi*; Shimasaki, Kotaro*; Yamamoto, Kosuke*; Shintate, Morio*; Kamachi, Yuichiro*; Bastakoti, B. P.*; Suzuki, Norihiro*; Motokawa, Ryuhei; Yamauchi, Yusuke*

Chemistry; A European Journal, 20(46), p.14955 - 14958, 2014/11

https://doi.org/10.1002/chem.201403762

Calculated positions of point nodes in the gap structure of the borocarbide superconductor YNiBC

Nagai, Yuki*; Kato, Yusuke*; Hayashi, Nobuhiko; Yamauchi, Kunihiko*; Harima, Hisatomo*

Physical Review B, 76(21), p.214514_1 - 214514_8, 2007/12

https://doi.org/10.1103/PhysRevB.76.214514

To determine the superconducting gap function of YNiBC, we calculate the local density of states around a single vortex core with the use of Eilenberger theory and the band structure calculated by local density approximation, assuming various gap structures with point nodes at different positions. We also calculate the angular-dependent heat capacity in the vortex state on the basis of the Doppler-shift method. Comparing our results with the scanning tunneling microscopy and spectroscopy experiment, the angular-dependent heat capacity and thermal conductivity, we propose the gap structure of YNiBC, which has the point nodes and gap minima along . Our gap structure is consistent with all results of angular-resolved experiments.

Consideration of molybdenum adsorption behavior of alumina by surface analysis

Suzuki, Yoshitaka; Niizeki, Tomotake*; Kitagawa, Tomoya*; Nishikata, Kaori; Matsukura, Minoru*; Hasegawa, Yoshio*; Tanase, Masakazu*; Fukumitsu, Nobuyoshi*; Yamauchi, Yusuke*; Ariga, Katsuhiko*; et al.

no journal, , 

no abstracts in English

Development of mesoporous alumina for domestic production of Mo/Tc

Fukumitsu, Nobuyoshi*; Yamauchi, Yusuke*; Kaneti, Y. V.*; Benu, D. P.*; Saptiama, I.*; Ariga, Katsuhiko*; Hatano, Kentaro*; Kumada, Hiroaki*; Fujita, Yoshitaka; Tsuchiya, Kunihiko

no journal, , 

no abstracts in English

Development of mesoporous alumina for domestic production of Mo/Tc

Fukumitsu, Nobuyoshi*; Yamauchi, Yusuke*; Kaneti, Y. V.*; Benu, D. P.*; Saptiama, I.*; Ariga, Katsuhiko*; Hatano, Kentaro*; Kumada, Hiroaki*; Fujita, Yoshitaka; Tsuchiya, Kunihiko

no journal, , 

no abstracts in English