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Cao M, Nishi R, Wang F. Automatic system for electron tomography data collection in the ultra-high voltage electron microscope. Micron 2017; 103:29-33. [PMID: 28946024 DOI: 10.1016/j.micron.2017.09.006] [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: 07/24/2017] [Revised: 09/07/2017] [Accepted: 09/11/2017] [Indexed: 10/18/2022]
Abstract
In this study, we report an automatic system for collection of tilt series for electron tomography based on the ultra-HVEM in Osaka University. By remotely controlling the microscope and reading the observation image, the system can track the field of view and do focus in each tilt angle. The automatic tracking is carried out with an image matching technique based on normalized correlation coefficient. Auto focus is realized by the optimization of image sharpness. A toolkit that can expand the field of view with technique of image stitching is also developed. The system can automatically collect the tilt series with much smaller time consumption.
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Affiliation(s)
- Meng Cao
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Research Centre for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
| | - Ryuji Nishi
- Research Centre for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Fang Wang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China
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Hamngren Blomqvist C, Gebäck T, Altskär A, Hermansson AM, Gustafsson S, Lorén N, Olsson E. Interconnectivity imaged in three dimensions: Nano-particulate silica-hydrogel structure revealed using electron tomography. Micron 2017; 100:91-105. [PMID: 28558343 DOI: 10.1016/j.micron.2017.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/27/2017] [Accepted: 04/27/2017] [Indexed: 11/29/2022]
Abstract
We have used Electron Tomography (ET) to reveal the detailed three-dimensional structure of particulate hydrogels, a material category common in e.g. controlled release, food science, battery and biomedical applications. A full understanding of the transport properties of these gels requires knowledge about the pore structure and in particular the interconnectivity in three dimensions, since the transport takes the path of lowest resistance. The image series for ET were recorded using High-Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM). We have studied three different particulate silica hydrogels based on primary particles with sizes ranging from 3.6nm to 22nm and with pore-size averages from 18nm to 310nm. Here, we highlight the nanostructure of the particle network and the interpenetrating pore network in two and three dimensions. The interconnectivity and distribution of width of the porous channels were obtained from the three-dimensional tomography studies while they cannot unambiguously be obtained from the two-dimensional data. Using ET, we compared the interconnectivity and accessible pore volume fraction as a function of pore size, based on direct images on the nanoscale of three different hydrogels. From this comparison, it was clear that the finest of the gels differentiated from the other two. Despite the almost identical flow properties of the two finer gels, they showed large differences concerning the accessible pore volume fraction for probes corresponding to their (two-dimensional) mean pore size. Using 2D pore size data, the finest gel provided an accessible pore volume fraction of over 90%, but for the other two gels the equivalent was only 10-20%. However, all the gels provided an accessible pore volume fraction of 30-40% when taking the third dimension into account.
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Affiliation(s)
- C Hamngren Blomqvist
- Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden; SuMo Biomaterials, VINN Excellence Centre, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - T Gebäck
- SuMo Biomaterials, VINN Excellence Centre, Chalmers University of Technology, S-412 96 Göteborg, Sweden; Mathematical Sciences, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - A Altskär
- SuMo Biomaterials, VINN Excellence Centre, Chalmers University of Technology, S-412 96 Göteborg, Sweden; Product Design and Perception, RISE Agrifood and Bioscience, Frans Perssons väg 6, S-402 29 Göteborg, Sweden
| | - A-M Hermansson
- SuMo Biomaterials, VINN Excellence Centre, Chalmers University of Technology, S-412 96 Göteborg, Sweden; Chemical and Biological Engineering, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - S Gustafsson
- Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - N Lorén
- Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden; SuMo Biomaterials, VINN Excellence Centre, Chalmers University of Technology, S-412 96 Göteborg, Sweden; Product Design and Perception, RISE Agrifood and Bioscience, Frans Perssons väg 6, S-402 29 Göteborg, Sweden
| | - E Olsson
- Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden; SuMo Biomaterials, VINN Excellence Centre, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
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Koshiya S, Yamashita S, Kimoto K. Microscopic observation of dye molecules for solar cells on a titania surface. Sci Rep 2016; 6:24616. [PMID: 27087005 PMCID: PMC4834531 DOI: 10.1038/srep24616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/21/2016] [Indexed: 01/16/2023] Open
Abstract
The lateral distribution and coverage of Ru-based dye molecules, which are used for dye-sensitized solar cells (DSCs), were directly examined on a titania surface using high-resolution scanning transmission electron microscopy (STEM). The clean surface of a free-standing titania nanosheet was first confirmed with atomic resolution, and then, the nanosheet was used as a substrate. A single dye molecule on the titania nanosheet was visualized for the first time. The quantitative STEM images revealed an inhomogeneous dye-molecule distribution at the early stage of its absorption, i.e., the aggregation of the dye molecules. The majority of the titania surface was not covered by dye molecules, suggesting that optimization of the dye molecule distribution could yield further improvement of the DSC conversion efficiencies.
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Affiliation(s)
- Shogo Koshiya
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Shunsuke Yamashita
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.,Department of Applied Chemistry, Kyushu University, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Koji Kimoto
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.,Department of Applied Chemistry, Kyushu University, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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