Broken symmetry and the variation of critical properties in the phase behaviour of molecular rhombus tilings

The tiling of surfaces has long attracted the attention of scientists, not only because it is intriguing intrinsically, but also as a way to control the properties of surfaces. However, although random tiling networks are studied increasingly, their degree of randomness (or partial order) has remain...

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Detalles Bibliográficos
Autores: Stannard, Andrew, Russell, James C., Blunt, Matthew O., Salesiotis, Christos, Giménez López, María del Carmen, Taleb, Nassiba, Champness, Neil, Garrahan, Juan, Beton, Peter, Schröder, Martin
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Universidad de Santiago de Compostela (USC)
Repositorio:Minerva. Repositorio Institucional de la Universidad de Santiago de Compostela
Idioma:inglés
OAI Identifier:oai:minerva.usc.gal:10347/32185
Acceso en línea:http://hdl.handle.net/10347/32185
Access Level:acceso abierto
Palabra clave:230326 Estructura de los compuestos inorgánicos
2304 Química macromolecular
Descripción
Sumario:The tiling of surfaces has long attracted the attention of scientists, not only because it is intriguing intrinsically, but also as a way to control the properties of surfaces. However, although random tiling networks are studied increasingly, their degree of randomness (or partial order) has remained notoriously difficult to control, in common with other supramolecular systems. Here we show that the random organization of a two-dimensional supramolecular array of isophthalate tetracarboxylic acids varies with subtle chemical changes in the system. We quantify this variation using an order parameter and reveal a phase behaviour that is consistent with long-standing theoretical studies on random tiling. The balance between order and randomness is driven by small differences in intermolecular interaction energies, which can be related by numerical simulations to the experimentally measured order parameter. Significant variations occur with very small energy differences, which highlights the delicate balance between entropic and energetic effects in complex self-assembly processes.