Nano Rods for Coloured Glasses Obtained by Hybrid Sol–Gel Coating

Abstract

Many new materials are now allowing new properties thanks to nanotechnology because this domain of physics gives possibilities to optimize targeted properties even if these materials react in very various influential parameters. Architectural, automotive, bone pathologies, environment, display applications are some concerned domains. The sol-gel process is a method allowing the realisation of coats at ambiant temperature, thus it is possible to realize Liquid Crystal Display (LCD), water-repellent coatings on privacy glass, antireflective coatings, hydrophobic or hydrophilic surfaces, bone tissue regeneration. In this study, the purpose is to show the thermal influence on a covered glass with a complex hybrid sol-gel solution. This coated glass is going to change color from red to orange under the heat influence. This color change effect comes from the evolution of various compounds organizations then/or from their loss during the degassing sequence. We show in spite of the complexity of the process that the responsible is mainly the organic dye. Thus the structure of the heated glass at 250 degrees C looks radically different than the heated one at 350 degrees C. SEM measurement allows to identify the surface compositions and to determine the elementary composition along the sample's cross section. TGA is used to justify a mass loss when samples are annealed. UV/Visible measurement is realized by two methods: in-line transmission to evaluate luminous flux and thus give colorimetric dot in the normalized CIE diagram and diffuse transmission to observe the size influence of the pigments. Infrared Reflectivity allows to evaluate the influence of species on the structure and to better target the nature of the lost compounds during annealing. TEM measurement proves that the obtained iron particles are nano rods for both samples.