Desenvolvimento metrológico de caracterização de grafenos obtidos por esfoliação de fase líquida

Abstract

Graphene is a carbon nanomaterial that has exceptional properties such as high mechanical strength, high thermal and electrical conductivity, among others. These properties enable a variety of applications to provide improvement in products and market sectors. In recent years, graphene has started to make its way out of the lab into “real world” products such as cars, accessories, cell phones and sneakers. However, there is still a barrier that affects the ascendancy of its commercialization. Such a barrier is the lack of standardization, as there is a diversity of materials sold as graphene, with different characteristics and properties. Therefore, it is necessary to understand the properties of this nanomaterial and develop standards for its characterization. This work falls within the scope of the nanometrology process aimed at the quality control of graphene obtained through exfoliation in the liquid phase. To this end, an interlaboratory study was carried out through the nucleation of a Laboratory Associated with Inmetro for Innovation in Graphene Characterization, at the Nanospectroscopy Laboratory (LabNS) of the Department of Physics at UFMG. The activities involved graphene measurements by Raman spectroscopy and atomic force microscopy. The procedures developed in this interlaboratory study allowed obtaining important information about the qualification of graphene from structural properties such as number of layers, defect density and lateral size. The results indicate the possibility of applying the procedures in other laboratories to corroborate the development of nanometrology in graphene. In parallel with interlaboratory activities, joined the ABNT study committee, where activities were carried out together with the two-dimensional materials working group, which led to the publication of the first Brazilian standard on graphene in early 2023 (ABNT ISO/TS 21356-1:2023). In addition, two other documents are in the process of being adopted. Another activity performed was participation in an international interlaboratory study promoted by VAMAS.