Influência de nanopartículas de óxido de grafeno em compósitos cimentícios com fibras poliméricas de máscaras faciais

Abstract

The volume produced and incorrect disposal of N-95 masks generates nonbiodegradable waste and becomes a problem of global proportions. Therefore, it requires ecologically correct solutions, thus enabling its study as synthetic fibers in the production of materials for civil construction. In this sense, in a previous analysis on the addition of N-95 mask fibers in a predefined mix of mortar produced with the addition of marble powder and silica fume, a 50% decrease in compressive strength and a 30% decrease in compressive strength were observed. traction, in addition to increasing the absorption rate by around 50%, which impairs durability and limits the application of the product obtained. Therefore, this research aimed to investigate the properties of the predefined trace when adding graphene oxide nanoparticles (NOG) to the mixture. For the experimental program, 4 new samples were made, containing 0%; 0.7%; 1.4% and 2.0% N-95 mask fibers and 0.02% NOG (both in relation to the amount of binder), which were evaluated for their physical, mechanical and chemical properties. The results found indicate a possibility for reusing N-95 masks as synthetic fibers for reinforcement in mortars. Based on the reference sample and considering compressive strength, in samples containing dry fibers and NOG, the loss of resistance reached 33% and, in samples with the addition of moistened fibers and NOG, the reduction was 36.8%. As for tensile strength, there was an increase of 4.5% in samples with the addition of dry fibers and NOG and an increase of 1.1% in samples containing moistened fibers and NOG. Absorption rates were also influenced by the addition of graphene oxide, with reductions of up to 58% in samples containing NOG and dry fibers and up to 73% in samples containing NOG and moist fibers. Thus, it can be concluded that graphene oxide benefits mortars with the addition of polymeric fibers, improving their physical and mechanical properties and enabling the reuse of materials. It is also noteworthy, based on the analyzes carried out to date, that additions of up to 0.7% of reused polymeric fibers and 0.02% of NOG are ideal for, considering resistance and permeability, promoting the reuse of N-masks. 95 to produce polymer fibers. This study also opens possibilities for new analyzes to be developed, improving the results found so far. Finally, this research contributes to the Brazilian national agenda in the context of sustainable progress, as it analyzes the addition of polymer fibers from waste into cement mixtures, produced with different waste, to obtain gains in the mechanical properties and durability of the composite, favoring environmental, social, economic indicators and technological innovation.