10 research outputs found
Comparative study of layer-by-layer deposition techniques for poly(sodium phosphate) and poly (allylamine hydrochloride)
UPNa. Departamento de IngenierÃa Eléctrica y Electrónica. Laboratorio de Dispositivos Ópticos NanoestructuradosAn inorganic short chain polymer, poly(sodium phosphate), PSP, together with poly(allylamine hydrochloride), PAH,
is used to fabricate layer-by-layer (LbL) films. The thickness, roughness, contact angle, and optical transmittance of
these films are studied depending on three parameters: the precursor solution concentrations (10−3 and 10−4 M),
the number of bilayers deposited (20, 40, 60, 80, and 100 bilayers), and the specific technique used for the LbL
fabrication (dipping or spraying). In most cases of this experimental study, the roughness of the nanofilms increases
with the number of bilayers. This contradicts the basic observations made in standard LbL assemblies where the
roughness decreases for thicker coatings. In fact, a wide range of thickness and roughness was achieved by means
of adjusting the three parameters mentioned above. For instance, a roughness of 1.23 or 205 nm root mean square
was measured for 100 bilayer coatings. Contact angles close to 0 were observed. Moreover, high optical transmittance
is also reported, above 90%, for 80 bilayer films fabricated with the 10−4 M solutions. Therefore, these multilayer
structures can be used to obtain transparent superhydrophilic surfaces.This work was supported by the Spanish Economy and Competitiveness
Ministry-FEDER TEC2010-17805