Influência de adições de grafeno e nanocompósitos Cds-diatomita nas propriedades autolimpantes de argamassa para rejuntamento

• Autor(a) principal: Prudente, Isis Nayra Rolemberg
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: http://ri.ufs.br/jspui/handle/riufs/13133
• topic: Engenharia de materiais; Argamassa; Rejuntamento; Catálise; Algas; Nanocompósitos (Materiais); Fotocatálise; Chlorella vulgaris; Scenedesmus sp; Grafeno; Nanocompósito CdS-diatomita; Mortars; Joint; Photocatalysis; Algae; Graphene; CdS-diatomite nanocomposite; ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA

The evaluation of the functionality of graphene and CdS/diatomite nanocomposite as mortar additives for self-cleaning properties was carried out with the preparation of mixtures of a nanocomposite of cadmium sulphide (CdS) anchored in diatomite and graphene nanoplates in 1.5% and 2.5% of graphene by weight of nanocomposite. The self-cleaning mortars were prepared by adding graphene, the CdS nanocomposites and the CdS/graphene mixtures in a commercial cementitious joint mortar, with the main goal of promoting microalgae inhibition. Starting materials and mortars were characterized by X-ray diffraction, Raman, infrared and diffuse reflectance UV-vis spectroscopies. The photocatalytic activity was evaluated from methylene blue dye degradation assays in the presence and absence of UV-A radiation, as well as tests of chlorophyll degradation of a biofilm composed of Chlorella vulgaris and Scenedesmus sp., and its growth inhibition. The results indicate that the modified mortars with CdS/graphene mixtures obtained the best photocatalytic responses, degrading approximately 18% of the dye in six hours of testing, approximately 8% more than those mortars modified with the pure CdS nanocomposite. Regarding the biofilm degradation and its inhibition, the pure graphene modified mortar was the most efficient. In chlorophyll degradation tests on biofilms, this sample is presented the whitest gray level. The microalgae growth inhibition test showed that the sample modified only with graphene had, on average, 2.5% micoalgae coverage by the end of 8 weeks of testing, while the control sample presented an average 87% of algae coverage. This result was pointed out in the chlorophyll degradation test, in which RG sample presented the whitest gray level, therefore, it was the most efficient in the biofilm degradation.