Película multifísica retificadora à base de cristal líquido nemático para aplicação sobre vidros

• Autor(a) principal: SILVA, Vinícius Fernando da
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/9372
• topic: Cristal líquido; Materiais nanoestruturados; Diodos; Filmes finos; Retificação térmica; Retificação óptica; Simulação computacional; CIENCIAS EXATAS E DA TERRA::FISICA

Nowadays, phononics, which aims to develop thermal analogues of usual electronic components (replacing the transport of electrical charge with heat), has become an important issue given the need for a better use of energy resources, since the planet’s demand only increases. The detection and treatment of thermal and optical signals are crucial for various applications. However, some of the materials used (graphene structures and carbon nanotubes, for example) are expensive and depend on supercomputers to use complex techniques. Other materials with a lower cost show similar results. In this work, we show a device, a film, that simultaneously rectifies heat and light. The multiphysical rectifier film consists of several diodes confined in a borosilicate container, the diodes in turn are shaped like a conical frustum tubes with an alternative material, the 5CB nematic liquid crystal, with a radial escape desclination (defect with asymmetry by translational inversion along the axis that spontaneously appears in cylindrical cavities). With the director vector we obtain the conductivity tensor thermal and tensor dielectric permittivity for each 5CB diode. Once the direction of the heat flow is defined, we solve the Fourier and Laplace equations to obtain the spatial temperature field and the electromagnetic wave equations using finite element analysis software. Thus, we obtain numerically thermal and optical rectifications, respectively, 31 % and 1057 %, similar to carbon nanotube thermal diodes and optical diodes based on photonic crystals. We believe that the proposed film can contribute to the economy of rectifying material, in the miniaturization of complex systems, to develop new structured devices, in addition to being an alternative use of liquid crystals in non-display devices, with application in controlling the flow of heat and light through surfaces.