Synthesis of monomers for obtaining liquid-crystalline elastomers with smectic mesophases

Abstract

Liquid crystal elastomers with smectic mesophases are materials that exhibit both solid and liquid properties, due to the nature of the molecules that make up their structure, known as mesogens. This type of materials has been the subject of intense research due to their diverse properties and applications. The compatibility of the mesogens that make up the elastomer with other compounds that have, among others, optical or magnetic properties, makes it possible to obtain intelligent materials capable of providing multiple types of responses when exposed to stimulus. In this project, we will focus on the study of elastomers in which a fluorogenic group, carbazole, a molecule capable of emitting fluorescence, has been incorporated. The deformation of the obtained material allows the modification of its fluorescent response, due to enhanced interactions between the mesogenic units and the fluorophores present in the matrix, thus creating a mechanoluminescent sensor. The described phenomenon will be the main object of study of the project. This will commence with the synthesis and characterization, using spectroscopic techniques such as IR and NMR, of the mesogens that will constitute the desired liquid crystal elastomers with smectic mesophases, followed by the preparation and characterization of the elastomers themselves through techniques such as differential scanning calorimetry and X-ray diffraction. Different elastomers will be prepared, differing in the length of the alkyl chain that connects the fluorescent group to the polymer chain. Finally, once obtained, their mechanofluorescent capacity will be assessed by means of fluorescence spectroscopy, with the aim of testing their effectiveness and potential as optical force sensors, as well as the influence of certain features of the fluorophores used.