Colloids in complex fluids

When particles, droplets or bubbles are dispersed in complex nematic fluids, they are not affected only by more commonly known colloidal interactions, such as steric, Coulomb and van der Waals but also by elastic interactions that originate from the distortions of the orientation order of the nematic fluids -- typically the nematic elasticity. Charged colloids in contact with liquids containing ions are in equilibrium accompanied by double layers, consisting of surface charge and diffuse ion cloud in the fluid, which again determine intraparticle interactions. We study the effects of surface properties, shape, size and topology of particles, as well as external confinment, geometry and external fields with the aim to develop tunable, controllable, and possibly self-assembled, materials for use in metamaterials, photonics and as energy storage devices.

Selected papers

  • A. Matavž, U. Uršič, J. Močivnik, D. Richter, M. Humar, S. Čopar B. Malič and V. Bobnar From coffee stains to uniform deposits: Significance of the contact-line mobility, Journal of Colloid and Interface Science 2, 608 (2021). [Link] [PDF].

  • J.C. Everts, B. Senyuk, H. Mundoor, M. Ravnik and I.I. Smalyukh, Anisotropic electrostatic screening of charged colloids in nematic solvents, Sci. Adv 7, eabd0662 (2021). [Link] [PDF].

  • A. P. Almeida, J. Canejo, U. Mur, S. Copar, P. L. Almeida, S. Žumer and M. H. Godinho Spotting plants’ microfilament morphologies and nanostructures, Proc. Natl. Acad. Sci., 10.1073/pnas.1901118116 (2019). [Link] [PDF].

  • B. Senyuk, J. Aplinc, M. Ravnik and I. I. Smalyukh, High-order elastic multipoles as colloidal atoms, Nature Comm. 10, 1825 (2019). [Abstract] [PDF].

  • C. C. Tartan, J. J. Sandford O Neill, P. S. Salter, J. Aplinc, M. J. Booth, M. Ravnik, S. M. Morris, and S. J. Elston, Read on Demand Images in Laser-Written Polymerizable Liquid Crystal Devices, Adv. Optical Mater. (2018), [Abstract] [PDF]. Highlighted as News & Views in Nature Photonics [LINK].

  • T. Potisk, D. Svenšek, H. R. Brand, H. Pleiner, D. Lisjak, N. Osterman and A. Mertelj, Dynamic magneto-optic coupling in a ferromagnetic nematic liquid crystal, Phys. Rev. Lett. 119, 097802 (2017). [Abstract] [PDF].

  • P. M. Rupnik, D. Lisjak, M. Čopič, S. Čopar and A. Mertelj, Field-controlled structures in ferromagnetic cholesteric liquid crystals, Science Advances 3, e1701336 (2017). [Abstract] [Open Access: PDF].

  • S. M. Hashemi, U. Jagodič, M. R. Mozaffari, M. R. Ejtehadi, I. Muševič and M. Ravnik Fractal nematic colloids, Nature Comm., 8, 14026 (2017). [Link] [PDF].

  • U. Tkalec, M. Ravnik, S. Čopar, S. Žumer and I. Muševič Reconfigurable knots and links in chiral nematic colloids, Science 333, 6038 (2011). [Link] [PDF].

  • M. Ravnik and S. Žumer Landau–de Gennes modelling of nematic liquid crystal colloids, Liq. Cryst. 36 , 1201-1214 (2009). [Link] [PDF].

  • M. Ravnik, M. Škarabot, S. Žumer, U. Tkalec, I. Poberaj, D. Babič, N. Osterman and I. Muševič Entangled nematic colloidal dimers and wires., Phys. Rev. Lett. 99, 247801 (2007). [Link] [PDF].