Influence of hydrophobic characteristic of organo-modified precursor on wettability of silica film

Abstract

The objective of this study is to design new hybrid silica materials as templates with hydrophobic properties, prepared at room temperature by a base catalyzed sol-gel process. As silica sources, organoalkoxysilanes functionalized with short hydrophobic chains were used: tetraethylorthosilicate (TEOS), methyltriethoxysilane (MTES), vinyltriethoxysilane (VTES), octyltriethoxysilane (OTES) and isobutyltriethoxysilane (iTES). It was shown that hydrophobicity of the functionalized silica nanoparticles increased as a function of length of the aliphatic chains (MTES < iTES < OTES) or when, instead of a hydrophobic alkyl chains (substituting group of silica precursors), a monounsaturated group was used (VTES). It was observed that the samples responded in a specific way to each type (hydrophilic or hydrophobic) of the dropped liquid. Even though the experiments were limited to short hydrocarbon chains, they showed that there is a threshold to reach high hydrophobicity of the hybrid surface.

The Influence of New Hydrophobic Silica Nanoparticles on the Surface Properties of the Films Obtained from Bilayer Hybrids

“…From analysis of the published data, two approaches for obtaining hydrophobic surfaces from particles and binder were notable: mixing the two phases [ 8 , 9 , 10 , 11 ], or deposition of particles over films obtained from different film-forming procedures [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. In this way, the possibility of obtaining superhydrophobic surfaces (contact angle > 160°) by mixing silica nanoparticles (SiO 2 NPs) with a binder obtained from tetraethoxysilane (TEOS) and a fluorosilane (FAS) through acid-catalyzed sol–gel process were reported [ 8 , 9 ].…”

“…The final process of hydrophobization was accomplished in dodecafluoroheptyl-methyldimethoxysilane vapors, showing excellent superhydrophobic property of silica film. Additionally, a covalent bond between the two phases can represent a special way of ensuring the deposition of silica particles over a polymer matrix [ 17 , 18 , 19 , 20 ]. “Layer-by-layer” (LBL) gradual deposition of dual-sized silica particles on glass functionalized with NH 3 + groups and modified with dodecyltrichlorosilane was shown in [ 21 ].…”

A nanolayer coating on polydimethylsiloxane surfaces enables a mechanistic study of bacterial adhesion influenced by material surface physicochemistry

“…Based on previous theoretical research about the length of polymer chain ends 47 and hydrophobicity affected by the length of polymer chain 49 , the PDMS containing lower crosslinker content is expected to display longer chain ends. In addition, more free, uncrosslinked PDMS chains were derived both from uncoated and coated PDMS samples having lower crosslinker content ( Figure 4C).…”

Development of ceramic membranes for resource recovery from brine through percrystallization

“…The methylated silica particles were prepared as colloidal silica sols via modified Stöber method (Yang et al, 2010;Li et al, 2020;Purcar et al, 2014). The molar ratios of the reactants used for synthesis are provided in Table 1.…”