Banca de DEFESA: ALINE ALENCAR EMERENCIANO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ALINE ALENCAR EMERENCIANO
DATE: 27/06/2023
TIME: 08:30
LOCAL: meet.google.com/wqf-tyaa-egk
TITLE:

Novel 2D materials for high-performance gas separation membranes and for epoxy-based composites 

KEY WORDS:

MXene membranes, H2/CO2 separation, MXene foam, purification, freeze-drying, epoxy-Ti3C2Tx composite.

PAGES: 142
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUMMARY:

Gas separation membranes for capturing CO2 from the environment are urgently required to minimize the greenhouse effect. One of the biggest challenges in this field is to produce an efficient gas separation membrane that is mechanically and chemically stable, as well as capable of separating gases through molecular size selection, known as molecular sieving. Currently, among different materials that have been used to produce membranes, graphene and graphene oxide are a potential competitor used for their fabrication trough etching. Due to their strong similarity to graphene, MXenes have become a great candidate to be processed as a membrane due to their ability to form nanochannels. However, some issues regarding purity, quality, waste, and storage of the nanosheets need to be improved. Additionally, due to the hydrophilic and attractive nature of their functional groups, there is a facility for the formation of agglomerates in their anhydrous form during storage, which hinder the reuse of this material to be used as reinforcement in epoxy-based matrices, for example. In this work, investigations were carried out regarding: (I) the production of a MXene membrane able to separate H2 and CO2 by controlling the distance between Ti3C2Tx nanosheets, (II) improvement of the synthesis efficiency of MXenes by creating a drying protocol to improve the purity of the nanosheets, and avoid agglomeration, and (III) improving the dispersion of Ti3C2Tx nanofillers in epoxy resin matrix by studying the influence of reinforcement morphology on dispersion and mechanical properties of epoxy-based composites. The results suggest that Ti3C2Tx was efficiently synthesized. Next, heat treatment under an oxygen-free atmosphere is an alternative for controlling the interlamellar distance by increasing the H2/CO2 separation factor. Additionally, a new protocol for drying and storing MXenes in its foam form was able to produce nanosheets by separating synthesized MXenes and non-etched MAX Phase, while maintaining their quality as well as the nature of their functional groups, which led to the production of well-deposited MXenes films. Finally, the good dispersion of Ti3C2Tx foam in the epoxy-based matrix led to an increase in the mechanical properties of the composite unlike the MXenes powder dried via the conventional method.

COMMITTEE MEMBERS:
Presidente - 2042234 - ANA PAULA CYSNE BARBOSA
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Interno - 345842 - UILAME UMBELINO GOMES
Externo à Instituição - DACHAMIR HOTZA - UFSC
Externa à Instituição - DANIELA BECKER - UDESC
Externo à Instituição - FORSCHUNGSZENTRUM JUELICH