2021 Fiscal Year Research-status Report
Effect of patchy particle designs on the bulk properties of the self-assembled structures
| Project/Area Number |
20K14437
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| Research Institution | Tohoku University |
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Principal Investigator |
Lieu Uyen 東北大学, 材料科学高等研究所, 助手 (00807042)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | self-assemble / inverse design / optimisation / patchy particle / kagome lattice / dodecagonal quasicrystal |
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| Outline of Annual Research Achievements |
A challenging goal to materials chemistry and physics is to construct superstructures from a building block. The superstructures of complex periodic lattices (e.g. diamond structure) or aperiodic structures (e.g. quasicrystals) are basics for the generation of novel materials with special optical, mechanical and thermal properties. The structure of these novel materials can be self-assembled from colloidal patchy particles. The degrees of freedom of the patchy particle have direct impact on the possible outcome structures. If one tries the self-assembly of any possible particle design, it consumes exhausting time and cost due to uncountable design of the patchy particle.
This can be solved by applying inverse design, i.e., from a desired target structure, we seek for a type of patchy particle that can self-assemble into the target structures. From the target structure, a class of computational iteration techniques is used to tune the design of particle until it can self-assemble into given target. We have developed and applied our inversed design optimisation scheme to find what is the best design of patchy particles so that they can assemble into given target structures. In particular, among many candidate patchy particles, we are capable of determining the suitable patchy particle creating a square lattice, kagome lattice, dodecagonal quasicrystal.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Due to COVID-19, in-person workshop and conferences were not possible, and it was hard to discuss with researchers. The procedures for submitting paper to journal were also slow. Despite the difficulties, we got one paper published and many virtual presentations.
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| Strategy for Future Research Activity |
Patchy particles are the particles with anisotropic surface patterns or patches on specific positions on the surface. The interaction of such particles is not only dependent on the distance, but also on their mutual orientations. Therefore, the patchy particles are capable of organising themselves into complex structures, which are important for the generation of novel materials.
One of the complex structures is quasicrystal. Quasicrystal are ordered structures lacking periodic translational symmetry. Quasicrystals may have 5-, 10-, 12-fold rotational symmetry while crystals possess 2-, 3-, 4-, and 6-fold rotational symmetry. The quasicrystal is interesting in both theoretical and application aspects. The quasicrystal can be applied in various application such as advanced coatings, reinforced composites, magnetism. The quasicrystal is formed by nucleation and growth. However understanding on the mechanism, the growth of quasicrystal is still incomplete.
We assemble a two-dimensional dodecagonal quasicrystal from the patchy particle of fivefold symmetry by Brownian dynamics simulation. We will investigate the growth of the dodecagonal quasicrystal using patchy particles and compare with the quasicrystal formed by isotropic particles.
On the other hand we expect that phasons and phason-like behaviour appear in the quasicrystal. Those will be studied under thermal fluctuation and/or shear deformation.
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| Causes of Carryover |
Due to Covid-19, it is hard to buy computer and join international conferences on-site. Such amount will be used for the conferences and cloud computing in the next year.
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