The influence of the hydrophobic agent, catalyst, solvent and water content on the wetting properties of the silica films prepared by one-step sol–gel method

Ramezani, Maedeh; Vaezi, Mohammad; Kazemzadeh, Asghar

doi:10.1016/j.apsusc.2014.11.013

Cited by 18 publications

(6 citation statements)

References 32 publications

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“…This approach may offer a simple and efficient option for the preparation of transparent materials with controlled structure and porosity that can also have different morphologies (membranes, monoliths, and fibers, among others) [ 24 ]. The structure and texture of materials produced by the sol–gel method are known to be influenced by the molar percentage of R x Si(OR’) 4-x [ 25 , 26 ], the pH [ 27 ], the proportions of H 2 O/TEOS and EtOH/TEOS [ 18 , 26 , 27 ], and the curing and drying methods [ 28 , 29 ]. Changes in these factors can produce significant variations in the density and porosity of the resulting xerogel.…”

Section: Introductionmentioning

confidence: 99%

Novel Organochlorinated Xerogels: From Microporous Materials to Ordered Domains

et al. 2021

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Hybrid silica xerogels combine the properties of organic and inorganic components in the same material, making them highly promising and versatile candidates for multiple applications. They can be tailored for specific purposes through chemical modifications, and the consequent changes in their structures warrant in-depth investigation. We describe the synthesis of three new series of organochlorinated xerogels prepared by co-condensation of tetraethyl orthosilicate (TEOS) and chloroalkyltriethoxysilane (ClRTEOS; R = methyl [M], ethyl [E], or propyl [P]) at different molar ratios. The influence of the precursors on the morphological and textural properties of the xerogels was studied using 29Si NMR (Nuclear Magnetic Resonance), FTIR (Fourier-Transform Infrared Spectroscopy), N2, and CO2 adsorption, XRD (X-ray Diffraction), and FE-SEM (Field-Emission Scanning Electron Microscopy). The structure and morphology of these materials are closely related to the nature and amount of the precursor, and their microporosity increases proportionally to the molar percentage of ClRTEOS. In addition, the influence of the chlorine atom was investigated through comparison with their non-chlorinated analogues (RTEOS, R = M, E, or P) prepared in previous studies. The results showed that a smaller amount of precursor was needed to detect ordered domains (ladders and T8 cages) in the local structure. The possibility of coupling self-organization with tailored porosity opens the way to novel applications for this type of organically modified silicates.

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Section: Introductionmentioning

confidence: 99%

Novel Organochlorinated Xerogels: From Microporous Materials to Ordered Domains

et al. 2021

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“…Figure 2 b displays the bands of isolated (or non-interacting) surface silanols and silanols interacting by hydrogen bonds at 3660 cm −1 and 3450 cm −1 , respectively. These bands, which are also characteristic of silicon xerogels, indicate the hydrophobic or hydrophilic nature of the material [ 49 ]. In addition to the aforementioned bands, a shoulder is observed at 550 cm −1 in all spectra, associated with the presence of 4-membered siloxane rings, (SiO) 4 [ 50 , 51 ], which is consistent with the aforementioned assumption of the predominance of cyclic species.…”

Section: Resultsmentioning

confidence: 99%

Hybrid Xerogels: Study of the Sol-Gel Process and Local Structure by Vibrational Spectroscopy

et al. 2021

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The properties of hybrid silica xerogels obtained by the sol-gel method are highly dependent on the precursor and the synthesis conditions. This study examines the influence of organic substituents of the precursor on the sol-gel process and determines the structure of the final materials in xerogels containing tetraethyl orthosilicate (TEOS) and alkyltriethoxysilane or chloroalkyltriethoxysilane at different molar percentages (RTEOS and ClRTEOS, R = methyl [M], ethyl [E], or propyl [P]). The intermolecular forces exerted by the organic moiety and the chlorine atom of the precursors were elucidated by comparing the sol-gel process between alkyl and chloroalkyl series. The microstructure of the resulting xerogels was explored in a structural theoretical study using Fourier transformed infrared spectroscopy and deconvolution methods, revealing the distribution of (SiO)4 and (SiO)6 rings in the silicon matrix of the hybrid xerogels. The results demonstrate that the alkyl chain and the chlorine atom of the precursor in these materials determines their inductive and steric effects on the sol-gel process and, therefore, their gelation times. Furthermore, the distribution of (SiO)4 and (SiO)6 rings was found to be consistent with the data from the X-Ray diffraction spectra, which confirm that the local periodicity associated with four-fold rings increases with higher percentage of precursor. Both the sol-gel process and the ordered domains formed determine the final structure of these hybrid materials and, therefore, their properties and potential applications.

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“…J. Chem. 2023, 15(1), [31][32][33][34][35][36][37] for sample preparation in further experiments were an anodized substrate, the application of a single coating layer, and drying at 220 °C ± 10 °C with a heating rate of 1 °C min -1 .…”

Section: Substrate Treatment Drying and Deposition Of The Coatingmentioning

confidence: 99%

“…To produce hydrophobic coatings by the Pechini method, most authors have analyzed single parameters in isolation, for example, the molar ratio of the reagents [33,34] and the time intervals for the addition of the reactants to the mixture [35]. However, such simple optimization methodologies do not consider the combined effects of different parameters.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Hydrophobic Coating Production by Pechini Method on Modified Aluminum Surface

Lima

Bittencourt

Alves

et al. 2023

Orbital: Electron. J. Chem.

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To fabricate a hydrophobic coating using the sol-gel method (Pechini), an experimental design using the drying time and chemicals ratio as variables was developed. The coating was deposited on an aluminum substrate (AA6061-T6) treated by acid solution or anodization method. The surface wettability was measured using a goniometric instrument. Coatings were fabricated using different numbers of layers, heating rates, and drying temperatures, and their morphologies were observed using visual analysis and scanning electron microscopy. The use of anodization treatment with a furnace ramp of 1 °C min-1, a drying temperature of 220 °C ± 10 °C, and single-layer application, produced a coating free of visible flaws and apparent damage. The coating was obtained with a 15:1 glycerin:citric acid ratio and sample pre-polymerization in the drying oven for 1 hour at 100 °C resulted in the highest contact angle, 62° ± 2°, which meets the ASTM D-7334-08 standard for a hydrophobic surface.

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The influence of the hydrophobic agent, catalyst, solvent and water content on the wetting properties of the silica films prepared by one-step sol–gel method

Cited by 18 publications

References 32 publications

Novel Organochlorinated Xerogels: From Microporous Materials to Ordered Domains

Novel Organochlorinated Xerogels: From Microporous Materials to Ordered Domains

Hybrid Xerogels: Study of the Sol-Gel Process and Local Structure by Vibrational Spectroscopy

Optimization of Hydrophobic Coating Production by Pechini Method on Modified Aluminum Surface

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