Banca de DEFESA: GUTEMBERGY FERREIRA DINIZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : GUTEMBERGY FERREIRA DINIZ
DATA : 23/07/2019
HORA: 15:00
LOCAL: Sala 414 do CTEC - UFRN
TÍTULO:

INVESTIGATION OF THE DRAG REDUCTION PHENOMENON IN PLASMA MODIFIED SYLGARD® 184 FLEXIBLE PIPES.

PALAVRAS-CHAVES:

rag Reduction, Superhydrophobic Surfaces, Plasma

PÁGINAS: 75
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Mecânica
RESUMO:

Drag is one of the main energy dissipation agents in engineering applications. Reducing dragging mechanisms have been studied in order to reduce this cost. The superhydrophobic surfaces have high water repellency and have been studied as an alternative mechanism to reduce drag. The high level of repellency is due to the hierarchical structures in the existing micro and nano scales, causing these surfaces to trap air layers and, consequently, impose a slipping condition. This type of surface has a high biomedical potential with several applications and that, acting as a drag reducer in internal flows, can solve the existing gap in the production of hydrophobic and flexible tubes. Based on this, the present work aims to investigate the phenomenon of drag reduction in flexible pipes manufactured in Sylgard® 184 elastomer and modified internally by low pressure plasma treatments. Treatments were performed in flat samples of the elastomer in use, aiming to find the best configuration of the plasma regime that would raise the hydrophobicity level of these. Atmospheres with 40% and 60%, and 20% and 80% of argon and acetylene respectively were used, varying in treatment times of 10, 15 and 20 minutes of acetylene exposure. The surface morphological and chemical modifications were analyzed and proved by XPS and AFM techniques, showing the impression of a rough structure on the nanometric scale with deposition of chemical elements by the polymerizing solution. The wettability of the treated surfaces was measured by the static contact angle with the water, proving the superhydrophobicity state.

MEMBROS DA BANCA:
Presidente - 2614274 - MICHELLE CEQUEIRA FEITOR
Interno - 2550377 - THERCIO HENRIQUE DE CARVALHO COSTA
Externo ao Programa - 2654020 - KLEIBER LIMA DE BESSA
Externo à Instituição - JAYME PINTO ORTIZ - USP