Functionalization of Silicon Carbide (SiC) for Abrasive Filament Production

Beatriz Inês Castanheira Mendes

Key information

Authors:

Beatriz Inês Castanheira Mendes (Beatriz Inês Castanheira Mendes)

Supervisors:

Sofia Maurícia Marteleira Teles; José Augusto Dâmaso Condeço (José Augusto Dâmaso Condeço)

Published in

07/28/2020

Abstract

This thesis addresses the advantages of performing a surface treatment using silane coupling agents to enhance the adhesive bonding performance of silicon carbide, SiC. The surface treatment involves a pre-treatment, followed by the functionalization. Various coupling agent/substrate ratios were studied to find the optimal conditions. Several functionalization tests were carried out with an ethanol/water ratio of 75/25, for alkylsilanes OCTEO, SIVO850 and 9896, and ethanol as the solvent for the silane AMMO. Regarding DAMO-T and 1401, toluene was used as the solvent and 0.5 % (V/V) of n-butylamine was used as a catalyst. Concerning the surface characterization of the functionalized particles, Fourier-transform infrared spectroscopy (FTIR) analysis, contact angle measurements and X-ray photoelectron spectroscopy (XPS) analysis, were performed. The FTIR analysis showed that all the organosilanes were present on the surface and unveiled the bond Si-O-Si proving that the organosilane was chemically bonded to the SiC substrate. The sample treated with the volume of 10.0 mL of AMMO presented the best performance in the contact angle measurement with the value of 134.4±0.2 º. Considering the achievement of good performance when using a small amount of organosilane, the OCTEO and DAMO-T silanes presented significantly high contact angles of 126.0±0.2 º and 114.4±0.4 º, with the application of 3.0 mL and 2.5 mL respectively. XPS analysis was only executed for the samples with the best contact angle results, concluding that the ones that presented greater coverage were the samples treated with the Dynasylan DAMO-T and AMMO.