Synthesis of Monodisperse Fluorinated Silica Nanoparticles and Their Superhydrophobic Thin Films

Abstract

:Monodispersive silica nanoparticles have been synthesized via the Stöber process and further functionalized by adding fluorinated groups using fluoroalkylsilane in an ethanolic solution. In this process, six different sizes of fluorinated silica nanoparticles of varying diameter from 40 to 300 nm are prepared and used to deposit thin films on aluminum alloy surfaces using spin coating processes. The functionalization of silica nanoparticles by fluorinated group has been confirmed by the presence C-F bonds along with Si-O-Si bonds in the thin films as analyzed by Fourier transform infrared spectroscopy (FTIR).The surface roughnesses as well as the water contact angles of the fluorinated silica nanoparticle containing thin films are found to be increased with the increase of the diameter of the synthesized fluorinated silica nanoparticles. The thin films prepared using the fluorinated silica nanoparticles having a critical size of 119 ± 12 nm provide a surface roughness of ∼0.697 µm rendering the surfaces superhydrophobic with a water contact angle of 151 ± 4°. The roughness as well as the water contact angle increases on the superhydrophobic thin films with further increase in the size of the fluorinated silica nanoparticles in the films.

Nano-micro structured superhydrophobic zinc coating on steel for prevention of corrosion and ice adhesion

“…The manufacturer of the RTV silicone specified that it contains mainly three different molecules: trimethoxymethylsilane, hexamethyldisilazane and octamethylcyclotetrasiloxane. The peaks at 800 and 1100 cm −1 correspond to the asymmetric stretching vibration of Si-O-Si group [38] and [42]. A peak approximately at −1 is due to the Si-O-C bond.…”

“…Two peaks at 1150 and 910 cm −1 are due to Si-N bondings [43]. The peaks at 1400, 2950 and 3000 cm −1 were assigned to -CH3 [38] and [42] as silicone contains plenty of methylated groups (-CH3). The presence of -CH3 as well as -CH2 together reduces the surface energy and enhances the water contact angle to a surface that leads to the superhydrophobic properties.…”

Surface Modification of Sol-Gel Silica Antireflective Coatings by F-PMHS: A Simple Method for Improvement of Amphiphobicity

“…The absorption band at 961 cm −1 is attributed to -Si-OH [22]. After F-PMHS surface modification, there are two new absorption bands at 900 cm −1 and 2167 cm −1 corresponding to -Si-C and -Si-H of F-PMHS, respectively [23]. In addition, the intensity of absorption band at 2964 cm −1 is strengthen while that of absorption band at 961 cm −1 is weakened gradually with the increasing F-PMHS concentration.…”

“…It is difficult to demonstrate the existence of amphiphobic-CF 3 groups by FTIR because its absorption bands are similar to those of -CH 3 [23]. So the characterization of XPS is carried out further.…”

Superhydrophobic organic-inorganic thin films on aluminum by a simple one-step electrochemical process

“…Due to the versatile applications of superhydrophobic surfaces researchers all around the world is are continuously working in this field of research [2][3][4][5][6]. Our group is actively working in the fabrication of superhydrophobic surfaces on aluminum and other metal surfaces using different techniques [7][8][9][10][11][12][13][14][15][16][17]. For example, we have previously shown that copper surfaces can be made superhydrophobic by a simple one-step electrochemical process.…”