CHARGEDANISOTROPY · Interplay of anisotropy and interactions in charged colloidal systems
7РП — „Хора“ (Действия „Мария Кюри“)
- Период
- 2011-09-01 → 2012-08-31
- Финансиране от ЕС
- 90 024 €
- Участници
- 1
- Схема
- MC-IEF
Линиите свързват координатора с партньорите.
Накратко на български
Заредените нанодискове и частици, подобни на тези в глината, се анализират чрез компютърни симулации, за да се види как се подреждат в различни структури. Това помага да се разбере как взаимодействието между частиците влияе върху свойствата на материалите.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Interplay of anisotropy and interactions in charged colloidal systems
Motivated by the observed intriguing phase behaviour of charged colloidal platelets and nanosheets, we investigate the phase behaviour of ultrathin charged disks by means of Monte-Carlo simulations. The electrostatic interactions are taken into account through an effective two-body interaction potential with the form of anisotropic Yukawa potential that is obtained within formalism of linearised Poisson - Boltzmann. We find that the peculiar angular dependence of this potential leads to a very rich phase behaviour for charged disks. Upon varying density and ionic strength, we recognise eight distinct microstructures, four of which are orientationally disordered. They consist of isotropic fluid, plastic crystal, random stacks and a novel structure of intergrowth texture. Investigating the dynamics in the orientationally disordered structures, we find that random stacks and intergrowth texture exhibit a very slow orientational dynamics, while their translational dynamics is diffusive. This behaviour resembles that of an orientational glass. The orientationally ordered phases appear at higher densities include two liquid-crystalline phases, i.e. nematic stacks and columnar hexagonal phase and two crystalline phases with fcc-like and hexagonal symmetry. We compare our obtained phase behaviour with that of Gibbsite and clay particles. We find that our model system agrees with the observed experimental phase behaviour in some regions of explored parameters.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
In this proposal we present a program of research and training in the area of soft condensed matter and statistical physics, focusing on understanding the role of long ranged interactions on phase behavior of anisotropic colloids. The Interesting interplay between anisotropic shape, long range interactions and its consequences on the phase behavior ofnanoparticles is a challenging problem which is far from well-understood. As an important step towards realizing this goal, we aim for a systematic study of both equilibrium and non-equilibrium phases of charged anisotropic colloids with axial symmetry. This can be envisaged in the general framework of charged spheroidal particles. The research project will explore the phase behavior of charged spheroids as a function of various control parameters (charge, size, aspect ratio and ionic strength). This model system has direct implications for the system of clays, which are a particular group of anisotropic colloids (platelet shapes), with widespread applications. An important issue in this respect to be resolved is to understand why the isotropic-nematic transition is preempted by a gel-like phase in some clays, while the reverse behavior (nematic order observed before gel phase upon increasing clay density) has been reported in seemingly very closely related compounds. We plan a direct collaboration with the experimental groups working on clays in University of Paris Sud (Patrick Davidson) and Ecole Polytechnique de Paris (Pierre Levitz) and as a result comparison of our results with experimental data is an essential part of project.""
Оригинален текст от CORDIS (на английски).
Участници
- CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS · ParisКоординаторФранция
Връзки
Данни: CORDIS, © Европейски съюз