H2020Индивидуална стипендия2016–2018

MagNem · Hydrodynamics of Ferromagnetic Nematic Liquid Crystals

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2016-10-01 → 2018-09-30
Финансиране от ЕС: 145 288 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Феромагнитните нематични течни кристали, създадени чрез смесване на магнитни наночастици с течни кристали, изследват връзката между структурата и свойствата на материята. Това помага за разбирането на взаимодействието между магнетизма и еластичността на течностите при стайна температура.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Hydrodynamics of Ferromagnetic Nematic Liquid Crystals

MagNem was designed as an interdisciplinary project, where the development of new materials, the characterization of the static and dynamic properties together with theoretical modelling gathered to reach the proposal’s goals. The experimental realization of true ferromagnetic nematics (FNLC) by the Host group constitutes an outstanding step opening a new field in soft matter physics which was explored by MagNem. The main goal of MagNem was to provide a deep knowledge of the structure-properties relationship, understanding the variety of exploitable static and dynamic properties (e.g. converse magneto-electric and magneto-optic effects, electro- and magneto- rheological properties) arising from the coupling of the mesomorphic elasticity and the magnetization. Although initially proposed in the 70's, it was not till 2013 that the Scientist in Charge experimentally achieved a stable dispersion of magnetic nanoparticles in a nematic liquid crystal which lead to a true fluid ferromagnetic phase at room temperature. Such a breakthrough was accomplished in suspensions of Sc-substituted barium hexaferrite (BaHF) magnetic nanoplatelets suspended in 5CB. The particle's platelet shape together with perpendicular anchoring (dodecylbenzenesulphonic acid surfactant - DBSA) induce a quadrupolar nematic director field around the platelets, preventing their aggregation in the director direction. In addition, magnetic interactions between the platelets seem to be such that parallel, that is ferromagnetic, ordering of the dipoles is promoted resulting in the macroscopic magnetization M. The magnetization M and the director n are thus coupled through the nanoplatelets surface anchoring of the nematic liquid crystal (NLC) molecules. Such coupling is responsible for a variety of distinct behaviours under the application of external magnetic fields resulting into field-control of the material properties, which constitutes an encouraging basis for applications in magneto-optic devices.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Experimental realization of ferromagnetic ferrofluids has been a long standing challenge which was recently overcome by the ground-breaking research of A. Mertelj et al. at the Host group. They have successfully combined soft-matter and magnetic-particle physics to achieve ferromagnetic order in suspensions of magnetic platelets in nematic liquid crystals. These ferromagnetic liquid crystals present the first experimental realization of polar nematic liquids and have opened up the possibility of studying an exciting new set of fundamental, previously inaccessible physical phenomena. MagNem aims to shed light on the understanding of complex hydrodynamics of these smart materials, in which flow, magnetic and nematic orderings are coupled. For this purpose, we will develop a range of new materials by changing surfactant/solvent combination. These advanced functional composites will exhibit different elastic, magnetic and steric interparticle interactions, giving us a perfect opportunity to focus on how the parameters governing the hydrodynamics of the system depend on the microscopic picture. The conjunction of nematic and magnetic ordering makes these colloidal systems responsive to both electric and magnetic fields and thus perfect candidates for applications in electro-/magneto-optic devices and magneto-optical flow sensing microfluidics. We will develop methods for the determination of dynamic parameters by combining magnetic, electric and mechanical strain fields and will work in collaboration with expert theoretical physicists which will model the experimentally observed phenomena. Our work will generate a fundamental understanding of the complex dynamics of ferromagnetic nematic liquid crystals, providing the necessary knowledge for material-property tailored design based on solvent/particle/surfactant combination and will lead to new insights for applications in the field of magneto-optics and lab-on-a-chip microfluidics with improved magneto flow control.

Оригинален текст от CORDIS (на английски).

Участници

INSTITUT JOZEF STEFAN · LjubljanaКоординаторСловения