TY - JOUR
T1 - From superhydrophilic to superhydrophobic surfaces by means of polymeric Layer-by-Layer films
AU - Lopez-Torres, Diego
AU - Elosua, Cesar
AU - Hernaez, Miguel
AU - Goicoechea, Javier
AU - Arregui, Francisco J.
PY - 2015/10/1
Y1 - 2015/10/1
N2 - In this paper a nanocoating that shows a superhydrophilic behavior (with a contact angle close to 0°) is transformed into a superhydrophobic nanofilm (whose contact angle is 165°) following a procedure that needs no nanoparticles to generate the nano-roughness required for superhydrophobicity. The superhydrophilic nanocoating was fabricated using poly (allylamine hydrochloride) (PAH) and poly (sodium phosphate) (PSP) combined by means of the Layer-by-Layer (LbL) technique. Seven different nanocoatings were constructed with different number of bilayers (4, 8, 12, 16, 20, 30 and 40) being the concentration of both polymers 10 −3 M. The analysis was conducted studying three different features: roughness, thickness and contact angle. The results show that initially, the contact angle of the nanofilms above 20 bilayers is close to 0°, that is, the minimum value for a superhydrophilic coating. These surfaces were functionalized using 1H,1H,2H,2H-Perfluorodecyltriethoxsilane to transform them into hydrophobic coatings by Chemical Vapor Disposition (CVD). Thereafter, the nanofilms showed a superhydrophobic behavior with a contact angle of 165° for the 40 bilayers films. The results of roughness and the images of AFM prove that the morphology of the nanocoating is preserved.
AB - In this paper a nanocoating that shows a superhydrophilic behavior (with a contact angle close to 0°) is transformed into a superhydrophobic nanofilm (whose contact angle is 165°) following a procedure that needs no nanoparticles to generate the nano-roughness required for superhydrophobicity. The superhydrophilic nanocoating was fabricated using poly (allylamine hydrochloride) (PAH) and poly (sodium phosphate) (PSP) combined by means of the Layer-by-Layer (LbL) technique. Seven different nanocoatings were constructed with different number of bilayers (4, 8, 12, 16, 20, 30 and 40) being the concentration of both polymers 10 −3 M. The analysis was conducted studying three different features: roughness, thickness and contact angle. The results show that initially, the contact angle of the nanofilms above 20 bilayers is close to 0°, that is, the minimum value for a superhydrophilic coating. These surfaces were functionalized using 1H,1H,2H,2H-Perfluorodecyltriethoxsilane to transform them into hydrophobic coatings by Chemical Vapor Disposition (CVD). Thereafter, the nanofilms showed a superhydrophobic behavior with a contact angle of 165° for the 40 bilayers films. The results of roughness and the images of AFM prove that the morphology of the nanocoating is preserved.
KW - CVD technique
KW - Functionalized surfaces
KW - Hydrophilic and hydrophobic films
KW - Layer-by-Layer
KW - PSP-PAH
UR - http://www.scopus.com/inward/record.url?scp=84983452507&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2015.06.004
DO - 10.1016/j.apsusc.2015.06.004
M3 - Article
AN - SCOPUS:84983452507
SN - 0169-4332
VL - 351
SP - 1081
EP - 1086
JO - Applied Surface Science
JF - Applied Surface Science
ER -