Desarrollar un modelo CFD de una centrifugadora para obtención de grafeno por exfoliación mecánica

Abstract

It is presented as an alternative to improve the separation of the graphite layers incorporating zeolite and aims to simulate the fluid in the ANSYS software in such a way that it maximizes the speed of the particle for a certain model of blades in order to obtain graphene of acceptable quality. The execution of the investigation has as a starting point which is to apply the liquid phase graphite exfoliation method. Using the agitation equipment of the laboratory that has an impeller with flat blades inclined at 45° produces a shear at 700 RPM to achieve inelastic collisions between the graphite flakes and the zeolite nanoparticles. An experimental design of the Factorial type is followed that shows that extract 2 samples for each experimental test. Samples are taken from the centric part top and bottom of the container since turbulence is greater in this area with 0.82 𝐽⁄𝐾𝑔. To characterize the samples, the scanning electron microscope technique is used, it identifies graphene in few layers and other micrographs that indicate agglomerated flakes. It was proceeded with the simulation of fluid dynamics which was handled by the ANSYS software specifically the fluent tool states that by changing the impeller, a gentle peel and effective throughout the flow field. Finally, four inclined blades type models were studied, type disc, curved blades and the anchor blade type that generates more turbulence at 17.3 𝐽⁄𝐾𝑔. The results that were found were favorable since it was indeed verified that the addition zeolite produces a considerable improvement in exfoliation. Experimentation and simulation should work together to separate as many layers of graphite as possible and it is recommended to tilt the axis at a certain angle to observe the changes produced in the morphology.