Soft Matter Physics research seminar: Colloids get creative - key to open crystals

Dr Dwaipayan Chakrabarti (University of Birmingham) will be presenting a seminar on his research in soft matter physics.

Abstract: Open crystals are sparsely populated periodic structures [1], which, when composed of colloidal particles, are appealing for their variety of applications, for example, as photonic materials, phononic and mechanical metamaterials, as well as porous media [1-5]. Although colloidal particles are promising building blocks for bottom-up routes to crystals, programming self-assembly of colloidal particles into open crystals has proved to be elusive. Building on our recent work [6-8], I will here talk about a hierarchical self-assembly scheme for triblock patchy particles to address the challenges met with programming self-assembly into colloidal open crystals [9-12]. The presentation will demonstrate in silico the hierarchical self-assembly of colloidal open crystals via what we call closed clusters, which stop to grow beyond a certain size in the first stage and are thus self-limiting. By employing a variety of computer simulation techniques, I will show that the design space supports different closed clusters (e.g. tetrahedra or octahedra with variable valences) en route to distinct open crystals. Our design rules thus open up the prospects of realising a number of colloidal open crystals from designer triblock patchy particles, including certain colloidal open crystals much sough-after for their attractive photonic applications. The relevant photonic band structures will be presented.

[1] M. Cates, Nature Mater., 2013, 12, 179-180.
[2] J. D. Joannopoulos, P. R. Villeneuve and S. Fan, Nature, 1997, 386, 143.
[3] K. Aryana and M. B. Zanjani, J. Appl. Phys., 2018, 123, 185103.
[4] X. Mao and T. C. Lubensky, Annu. Rev. Condens. Matter Phys., 2018, 9, 413.
[5] X. Mao, Q. Chen and S. Granick, Nature Mater. 2013, 12, 217.
[6] D. Morphew and D. Chakrabarti, Nanoscale, 2015, 7, 8343.
[7] D. Morphew and D. Chakrabarti, Soft Matter, 2016, 12, 9633.
[8] D. Morphew and D. Chakrabarti, Nanoscale, 2018, 10, 13875.
[9] D. Morphew, J. Shaw, C. Avins and D. Chakrabarti, ACS Nano, 2018, 12, 2355.
[10] A. B. Rao et al., Manuscript in communication, 2019.
[11] A. Neophytou et al., Manuscript in preparation, 2019.
[12] J. Shaw et al., Manuscript in preparation, 2019.

Host: Professor Helen Gleeson