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Directed Colloidal Structure at the Meso-Scale

Deliverables

Quantifying and controlling dynamics through rod characteristics

We will study the effects of particle characteristics (length, aspect ratio, flexibility) on single particle, Brownian dynamics: (i) Single rod dynamics in highly ordered phases; (ii) Effect of nearby phase transitions on the collective dynamics. Novel theoretical models will be applied using a grand canonical description mimicking the experiments. Experiments on cellulose and thermo-responsive rods to approach phase transitions will provide validation of the modelling, using high-speed cameras to capture so far inaccessible relevant times scales.

Directing the meso-phase structure by shear flow

Large oscillatory strains and steady shear flow will be applied to study shear-induced alignment of isotropic states and the distortion and melting of ordered LC phases.

Directing structure via chirality

We will study the competition between chirality-induced twist and long-range positional order on the cholesteric phase and the structure of higher-order liquid crystalline states by tuning the molecular chirality using mixtures of two mutants with opposite chiral handedness in combination with X-ray scattering and fluorescence microscopy.

Understanding the molecular origin of dynamically percolated states

We investigate: (i) The kinetic pathways that dominate temporal network formation in dispersions of rod-like particles; (ii) If translational and/or rotational motion provide the main route towards build-up and breakdown of cluster networks; (iii) The structure of the clusters for various types of interaction and external fields including flow; (iv) Whether the proximity to LC phases impacts upon the cluster size and structure, and if this affects the percolation threshold. We will use simulations, dynamical connectedness percolation theory, and in experiment a combination of dielectric spectroscopy, optical microscopy, rheology and radiation scattering.

Final report on WP1.2 and 1.3

Final report on sub-WPs 1.2 and 1.3; This is a follow-up on deliverables D1.3-1.5

Control of structure via confinement and quantification of the dynamics

We will study the competition between Frank elasticity, surface anchoring and interfacial tensions via confinement and study the underlying dynamics.

Properties of the IN interface of entropy-dominated systems

Create isotropic and nematic droplets to control the interplay between surface tension and Frank elasticity beyond the predetermined IN structures using microfluidics; Probe the structural behaviour of LC interfaces to understand interface behaviour of entropy-dominated systems

State diagram of the arrested states

We will measure a state diagram for glass and gel formation as a function of rod characteristics and interactions. The experimental systems provide tuneable repulsive and attractive interactions.

Quantifying and controlling dynamics through interactions and concentration

We will study effect of system characteristics (interactions, concentration) on structure and single particle, Brownian dynamics: (i) Single rod dynamics in highly ordered phases; (ii) Effect of nearby phase transitions on the collective dynamics. Novel theoretical models will be applied using a grand canonical description mimicking the experiments in WP 1.1 and 2.1. Experiments on cellulose and thermo-responsive rods to approach phase transitions will provide validation of the modelling, using high-speed cameras to capture so far inaccessible relevant times scales.

Directing the flow response by tuning particle characteristic

We will study the effect of polydispersity, flexibility, chirality and frozen in kinks on bulk flow behaviour in different LC phases, comparing results between industrial and model systems.

Supervisory board of the network

Completion of supervisory board of the network.

Production of thermo-responsive virus-based systems with varying length and flexibility

We will focus on the development of the following model system: Modification of rod-like virus particles such that the thickness can be tuned in situ. To this end, temperature responsive polymer shells will be grown onto the particle’s surface. The thickness and cross-link density of the polymer layer offers control over the volume fraction and the hardness of the rod particles. This deliverable will be a physical suspension of colloidal particles in a solvent.

Production of thermo-responsive silica rods

Fluorescently labelled silica particles will be synthesised, offering a complimentary, non-chiral, alternative system to the virus system, facilitating the real-space study of self-assembly and phase behaviour, also in the presence of other colloidal particles and solvents. This deliverable will be a physical suspension of colloidal particles in a solvent.

Project identity set and launch of DiStruc web portal

Project identity set in order to facilitate communication and create a visual identity to the project, DiStruc logo, brochure and a slide template will be created. The non-confidential general public area in the DiStruc web portal piloted by FOR will provide general background information which is not currently available in an accessible form to the general public. This information will enable interested educators, such as high school teachers, to integrate recently acquired knowledge into the curriculum early. Interested undergraduate students will find information complementing their classes. The program therefore will impact on the general public, and raise the interest in scientific research, from theory to advanced materials, thus taking an active role in advertising a career in research to young people. A restricted domain will be constructed in the web portal to which only the consortium will have access. Given the mix of PU and CO I have selected the more confidential dissemination level.

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Publications

The Connection between Biaxial Orientation and Shear Thinning for Quasi-Ideal Rods

Author(s): Christian Lang, Joachim Kohlbrecher, Lionel Porcar, Minne Lettinga
Published in: Polymers, Issue 8/8, 2016, Page(s) 291, ISSN 2073-4360
DOI: 10.3390/polym8080291

Self-organisation of semi-flexible rod-like particles

Author(s): Bart de Braaf, Mariana Oshima Menegon, Stefan Paquay, Paul van der Schoot
Published in: The Journal of Chemical Physics, Issue 147/24, 2017, Page(s) 244901, ISSN 0021-9606
DOI: 10.1063/1.5000228

Hierarchical bounding structures for efficient virial computations: Towards a realistic molecular description of cholesterics

Author(s): Maxime M. C. Tortora, Jonathan P. K. Doye
Published in: The Journal of Chemical Physics, Issue 147/22, 2017, Page(s) 224504, ISSN 0021-9606
DOI: 10.1063/1.5002666

Continuum percolation of polydisperse rods in quadrupole fields: Theory and simulations

Author(s): Shari P. Finner, Mihail I. Kotsev, Mark A. Miller, Paul van der Schoot
Published in: The Journal of Chemical Physics, Issue 148/3, 2018, Page(s) 034903, ISSN 0021-9606
DOI: 10.1063/1.5010979

Elementary Edge and Screw Dislocations Visualized at the Lattice Periodicity Level in the Smectic Phase of Colloidal Rods

Author(s): Andrii Repula, Eric Grelet
Published in: Physical Review Letters, Issue 121/9, 2018, ISSN 0031-9007
DOI: 10.1103/PhysRevLett.121.097801

Two-dimensional, blue phase tactoids


Published in: ISSN 0026-8976
DOI: 10.1080/00268976.2018.1496292

Colloidal liquid crystals in square confinement: isotropic, nematic and smectic phases

Author(s): Louis B G Cortes, Yongxiang Gao, Roel P A Dullens, Dirk G A L Aarts
Published in: Journal of Physics: Condensed Matter, Issue 29/6, 2017, Page(s) 064003, ISSN 0953-8984
DOI: 10.1088/1361-648X/29/6/064003

A quest for shear banding in ideal and non ideal colloidal rods

Author(s): C Lang, L Porcar, H Kriegs, M P Lettinga
Published in: Journal of Physics D: Applied Physics, Issue 52/7, 2019, Page(s) 074003, ISSN 0022-3727
DOI: 10.1088/1361-6463/aaf40c

Effects of particle stiffness on the extensional rheology of model rod-like nanoparticle suspensions

Author(s): Christian Lang, Jan Hendricks, Zhenkun Zhang, Naveen K. Reddy, Jonathan P. Rothstein, M. Paul Lettinga, Jan Vermant, Christian Clasen
Published in: Soft Matter, Issue 15/5, 2019, Page(s) 833-841, ISSN 1744-683X
DOI: 10.1039/c8sm01925h

Tumbling of Quantum Dots: Rheo-Optics

Author(s): Run Li, Marisol Ripoll, Naveen Reddy, Jan K.G. Dhont, Ruben Dierick, Zeger Hens, Christian Clasen
Published in: Langmuir, Issue 34/48, 2018, Page(s) 14633-14642, ISSN 0743-7463
DOI: 10.1021/acs.langmuir.8b02498

Rod-Like Virus-Based Multiarm Colloidal Molecules

Author(s): Alexis de la Cotte, Cheng Wu, Marie Trévisan, Andrii Repula, Eric Grelet
Published in: ACS Nano, Issue 11/10, 2017, Page(s) 10616-10622, ISSN 1936-0851
DOI: 10.1021/acsnano.7b06405

Perturbative density functional methods for cholesteric liquid crystals

Author(s): Maxime M. C. Tortora, Jonathan P. K. Doye
Published in: The Journal of Chemical Physics, Issue 146/18, 2017, Page(s) 184504, ISSN 0021-9606
DOI: 10.1063/1.4982934

Electric-field-induced shape transition of nematic tactoids

Author(s): Luuk Metselaar, Ivan Dozov, Krassimira Antonova, Emmanuel Belamie, Patrick Davidson, Julia M. Yeomans, Amin Doostmohammadi
Published in: Physical Review E, Issue 96/2, 2017, Page(s) 022706, ISSN 2470-0045
DOI: 10.1103/PhysRevE.96.022706