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Miura M, Sugiyama A, Oshikiri Y, Morimoto R, Mogi I, Miura M, Yamauchi Y, Aogaki R. Excess heat production of the pair annihilation of ionic vacancies in a copper redox reaction using a double bipolar MHD electrode. Sci Rep 2024; 14:1424. [PMID: 38228645 PMCID: PMC10792075 DOI: 10.1038/s41598-024-51834-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 01/10/2024] [Indexed: 01/18/2024] Open
Abstract
Through a copper double bipolar magnetohydrodynamic (MHD) electrode (MHDE) producing twice the amounts of ionic vacancies than a conventional single MHDE, the molar excess heat of the pair annihilation of ionic vacancies, 702 kJ mol-1 at 10 T on average was obtained in a copper redox reaction. It was about twice as large as that of a single MHDE, 387 kJ mol-1 at the same magnetic field. This result strongly suggests that a multi-channel bipolar MHDE will produce much greater excess heat. To conserve the linear momentum and electric charge during electron transfer in an electrode reaction, ionic vacancies are created, storing the solvation energy in the polarized core of the order of 0.1 nm, and the pair annihilation of the vacancies with opposite charges liberates the energy as excess heat. The promoted excess heat by the double bipolar MHDE with a diffuser at 10 T was 710 ± 144 kJ mol-1, whereas as mentioned above, 702 ± 426 kJ mol-1 was obtained by the same electrode without such a diffuser. From the theoretical excess heat of 1140 kJ mol-1, the collision efficiencies in pair annihilation were 0.623 ± 0.126 and 0.616 ± 0.374, respectively. From these results, the reproducibility of the thermal measurement was experimentally validated. At the same time, it was concluded that at magnetic fields beyond 10 T, the concentration of ionic vacancy and the collision efficiency take constant uppermost values.
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Affiliation(s)
- Makoto Miura
- Tohoku Polytechnic College, Kurihara, Miyagi, 987-2223, Japan.
| | | | - Yoshinobu Oshikiri
- Yamagata College of Industry and Technology, Matsuei, Yamagata, 990-2473, Japan
| | - Ryoichi Morimoto
- Saitama Industrial Technology Center, Kawaguchi, Saitama, 333-0844, Japan
| | - Iwao Mogi
- Institute for Materials Research, Tohoku University, Aoba-ku, Sendai, 980-8577, Japan
| | - Miki Miura
- Polytechnic Center Kimitsu, Kimitsu, Chiba, 299-1142, Japan
| | - Yusuke Yamauchi
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, 4072, Australia.
- Department of Materials Process Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan.
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea.
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Theory of Chiral Electrodeposition by Chiral Micro-Nano-Vortices under a Vertical Magnetic Field -1: 2D Nucleation by Micro-Vortices. MAGNETOCHEMISTRY 2022. [DOI: 10.3390/magnetochemistry8070071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Remarkable chiral activity is donated to a copper deposit surface by magneto-electrodeposition, whose exact mechanism has been clarified by the three-generation model. In copper deposition under a vertical magnetic field, a macroscopic tornado-like rotation called the vertical magnetohydrodynamic (MHD) flow (VMHDF) emerges on a disk electrode, inducing the precessional motions of various chiral microscopic MHD vortices: First, chiral two-dimensional (2D) nuclei develop on an electrode by micro-MHD vortices. Then, chiral three-dimensional (3D) nuclei grow on a chiral 2D nucleus by chiral nano-MHD vortices. Finally, chiral screw dislocations are created on a chiral 3D nucleus by chiral ultra-micro MHD vortices. These three processes constitute nesting boxes, leading to a limiting enantiomeric excess (ee) ratio of 0.125. This means that almost all chiral activity of copper electrodes made by this method cannot exceed 0.125. It also became obvious that chirality inversion by chloride additive arises from the change from unstable to stable nucleation by the specific adsorption of it.
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