Superhydrophobic surfaces are gaining considerable interest in a lot of different applications, and nonetheless, precise control over the wettability properties of such surfaces is still a challenge due to difficulties when controlling the effects independently induced on superhydrophobicity by the chemical and topological surface characteristics. We have fabricated engineered superhydrophobic surfaces onto poly(dimethylsiloxane) (PDMS) substrates by means of suitable CF4-plasma treatments. These treatments allowed the modification of both the morphological properties of the PDMS surface, due to a preferential etching of certain components of its macromolecules, and the chemical ones, by the deposition of a fluorinated layer. Chemical effects were separated from topological ones by performing a double replica molding process of the CF4-plasma-treated surfaces. This allowed us to obtain positive copies of the structured surfaces without the overlaying fluorinated coating affecting the surface chemistry. Such replicated surfaces showed a decrease of the contact angle if compared to the treated ones and therefore evidenced chemistry's weight in superhydrophobicity effects. In particular, we found that, for highly dense columnar-like PDMS microstructures, the effect of the plasma-deposited fluorinated layer covering surfaces produces an enhancement of the contact angle of about 20 degrees.

Influence of chemistry and topology effects on superhydrophobic CF4-plasma-treated poly(dimethylsiloxane) (PDMS)

MANCA, MICHELE;CORTESE, BARBARA;CINGOLANI, Roberto;GIGLI, Giuseppe
2008

Abstract

Superhydrophobic surfaces are gaining considerable interest in a lot of different applications, and nonetheless, precise control over the wettability properties of such surfaces is still a challenge due to difficulties when controlling the effects independently induced on superhydrophobicity by the chemical and topological surface characteristics. We have fabricated engineered superhydrophobic surfaces onto poly(dimethylsiloxane) (PDMS) substrates by means of suitable CF4-plasma treatments. These treatments allowed the modification of both the morphological properties of the PDMS surface, due to a preferential etching of certain components of its macromolecules, and the chemical ones, by the deposition of a fluorinated layer. Chemical effects were separated from topological ones by performing a double replica molding process of the CF4-plasma-treated surfaces. This allowed us to obtain positive copies of the structured surfaces without the overlaying fluorinated coating affecting the surface chemistry. Such replicated surfaces showed a decrease of the contact angle if compared to the treated ones and therefore evidenced chemistry's weight in superhydrophobicity effects. In particular, we found that, for highly dense columnar-like PDMS microstructures, the effect of the plasma-deposited fluorinated layer covering surfaces produces an enhancement of the contact angle of about 20 degrees.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11587/106028
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact