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Thèse de Doctorat
DOI
https://doi.org/10.11606/T.3.2011.tde-12122011-141829
Document
Auteur
Nom complet
Marcio Roberto da Silva Oliveira
Adresse Mail
Unité de l'USP
Domain de Connaissance
Date de Soutenance
Editeur
São Paulo, 2011
Directeur
Jury
Salvadori, Maria Cecília Barbosa da Silveira (Président)
Added, Nemitala
Gubitoso, Marco Dimas
Santos Filho, Sebastião Gomes dos
Temperini, Marcia Laudelina Arruda
Titre en portugais
Superfícies super-hidrofóbicas obtidas através de microestruturas litografadas.
Mots-clés en portugais
Efeito Lótus
Microcavidades
Super-hidrofobia
Resumé en portugais
Aqui apresentamos um modelo teórico para superfícies super-hidrofóbicas que são formadas por superfícies contendo padrões periódicos na forma de microcavidades. Com este modelo obtivemos a relação ideal entre profundidade e diâmetro das cavidades para que a superfície manifeste seu caráter super-hidrofóbico. Assim, fabricamos superfícies em PDMS (popular silicone) capazes de produzir ângulos de contato elevados. Produzimos amostras contendo microcavidades específicas (paralelepípedas, hexagonais e cilíndricas) as quais foram microfabricadas por litografia de feixes de elétrons e caracterizadas por Microscopia Eletrônica de Varredura (MEV), Microscopia de Força Atômica (AFM), e medidas de ângulo de contato. Os padrões das microcavidades das superfícies produzidas seguiram as considerações da teoria e as medidas dos ângulos de contato de avanço e recesso mostram boa concordância com as previsões do modelo. Portanto, podemos afirmar que a teoria aqui descrita permite projetar superfícies altamente hidrofóbicas.
Titre en anglais
Superhydrophobic surfaces obtained by microstructures lithographed.
Mots-clés en anglais
Lotus Effect
Microcavities
Superhydrophobia
Resumé en anglais
Here we present a theoretical model for super-hydrophobic surfaces formed by surfaces containing periodic patterns in the form of microcavities. With this model we obtained the ideal relationship between depth and diameter of the cavities so that the surface expresses a super-hydrophobic character. Thus manufacture of PDMS surfaces (with known silicone) is capable of producing high contact angles. We produced samples containing specific microcavities (parallelepipeds, hexagonal and cylindrical) which have been microfabricated by electron beam lithography and characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements. The patterns of the surfaces of the cavities produced following the considerations of theory and measurements of advancing and recending contact angles show good agreement with the model predictions. Therefore, we can attest that the theory described here allows the design of highly hydrophobic surfaces.
 
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Date de Publication
2011-12-15
 
AVERTISSEMENT: Le matériau se réfère à des documents provenant de cette thèse ou mémoire. Le contenu de ces documents est la responsabilité de l'auteur de la thèse ou mémoire.
  • Salvadori, M. C., et al. Design and fabrication of microcavity-array superhydrophobic surfaces [doi:10.1063/1.3466979]. Journal of Applied Physics [online], 2010, vol. 108, p. 024908-024908-6.
  • Salvadori, M. C., et al. Design and fabrication of superhydrophobic surfaces formed of microcavities [doi:10.1063/1.3327836]. Applied Physics Letters [online], 2010, vol. 96, p. 074101.
  • Salvadori, M.C., et al. Microcavity-array superhydrophobic surfaces: Limits of the model. Journal of Applied Physics, 2013, vol. 114, p. 174911.
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