Effect of the Synthesis Methods on Hydrophobic Properties of Modified Silicas

Goncharuk, Olena; Sulym, Iryna; Terpiłowski, Konrad; Pakhlov, E.M.

doi:10.1260/0263-6174.33.6-8.709

Cited by 3 publications

(2 citation statements)

References 5 publications

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“…The thermodynamic disadvantage of the water molecules' contact with non-polar surfaces causes a strong attraction of the molecules to each other. The injection of hydrophobized limestone-based particles into water disrupts the spatial structure of the strong hydrogen bonds formed by water molecules, for which energy is expended and heat is absorbed [59][60][61].…”

Section: Thermal Effects Of Powder Wetting With Different Polarity Li...mentioning

confidence: 99%

Hydrophilic–Hydrophobic Properties of the Surface of Modified Carbonate Fillers for Asphalt

Lebedev,

Yadykina,

Akimov

et al. 2023

J. Compos. Sci.

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The physicochemical modification of the filler allows changing the hydrophilic–hydrophobic properties and effectively influencing the processes occurring at the filler–binder interface, on which the physicomechanical characteristics of composites largely depend. The paper presents studies related to the modification of limestone-based filler effect on the degree of its hydrophobicity and wetting with liquids of different polarity, establishing the relationship between the characteristics of hydrophobized mineral powders and the adsorption capacity in relation to water. Using mechanochemical processing with hydrophobic components GF-1 and GF-2, it was possible to obtain fillers with a sufficiently high content of hydrophobic particles (58.2% and 85.9%, respectively). It was found that the results of the contact angle (123.6° and 114.5°, respectively) and the degree of hydrophobicity do not quite correlate with each other. It was noticed that the contact angle on the powder modified with GF-1 decreases with time. Studies of the powders’ thermal effects wetting of different polarity liquids via microcalorimetry allows us to establish that with an increase in the filler hydrophobicity degree, the integral heat of immersion decreases due to a significant decrease in the probability of chemical interactions between water and powder due to the adsorption of applied surfactants molecules on the limestone active centers. The revealed endothermic effects indicate the occurrence of physical interactions due to non-polar dispersion forces. Differences in the nature of heat release and heat absorption in modified fillers indicate significant differences in the composition and mechanism of action of the used surfactants, which affected the efficiency of hydrophobization. At the same time, a linear dependence of the moisture absorption and moisture indicators, determined by independent experiments, on the degree of hydrophobicity was established.

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Section: Thermal Effects Of Powder Wetting With Different Polarity Li...mentioning

confidence: 99%

Hydrophilic–Hydrophobic Properties of the Surface of Modified Carbonate Fillers for Asphalt

Lebedev,

Yadykina,

Akimov

et al. 2023

J. Compos. Sci.

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“…The use of complex MO cannot only improve the performance characteristics of the NC (such as thermal stability, durability [ 20 , 21 ]) but also significantly affect their structural characteristics [ 20 , 34 ]. The structure of the polymer adsorption layer defines such NC surface properties as hydrophilicity–hydrophobicity [ 34 – 36 ], compatibility with organics, adsorption capability, and reactivity [ 37 – 39 ]. The helix shape of PDMS with six Si–O bonds in a cycle [ 40 ] restricts the number of segments which can directly interact with a solid surface to form the hydrogen bonds SiO–H···O(Si(CH 3 ) 2 –) 2 .…”

Section: Introductionmentioning

confidence: 99%

Nanooxide/Polymer Composites with Silica@PDMS and Ceria–Zirconia–Silica@PDMS: Textural, Morphological, and Hydrophilic/Hydrophobic Features

et al. 2017

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SiO2@PDMS and CeO2–ZrO2–SiO2@PDMS nanocomposites were prepared and studied using nitrogen adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), measurements of advancing and receding contact angles with water, and microcalorimetry. The pore size distributions indicate that the textural characteristics change after oxide modification by poly(dimethylsiloxane) (PDMS). Composites are characterized by mainly mesoporosity and macroporosity of aggregates of oxide nanoparticles or oxide@PDMS nanoparticles and their agglomerates. The FT-IR spectra show that PDMS molecules cover well the oxide surface, since the intensity of the band of free silanols at 3748 cm−1 decreases with increasing PDMS concentration and it is absent in the IR spectrum at C PDMS ≥ 20 wt% that occurs due to the hydrogen bonding of the PDMS molecules to the surface hydroxyls. SEM images reveal that the inter-particle voids are gradually filled and aggregates are re-arranged and increase from 20 to 200 nm in size with the increasing polymer concentration. The highest hydrophobicity (contact angle θ = 140° at C PDMS = 20–40 wt%) is obtained for the CeO2–ZrO2–SiO2@PDMS nanocomposites. The heat of composite immersion in water shows a tendency to decrease with increasing PDMS concentration.

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Mitigating the impact of the static and cyclic loading on loose coastal saturated sands utilizing a waterproof and super-fast curing polymer

Dehkordi

Rowshanzamir

Hejazi

et al. 2021

Soil Dynamics and Earthquake Engineering

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Effect of the Synthesis Methods on Hydrophobic Properties of Modified Silicas

Cited by 3 publications

References 5 publications

Hydrophilic–Hydrophobic Properties of the Surface of Modified Carbonate Fillers for Asphalt

Hydrophilic–Hydrophobic Properties of the Surface of Modified Carbonate Fillers for Asphalt

Nanooxide/Polymer Composites with Silica@PDMS and Ceria–Zirconia–Silica@PDMS: Textural, Morphological, and Hydrophilic/Hydrophobic Features

Mitigating the impact of the static and cyclic loading on loose coastal saturated sands utilizing a waterproof and super-fast curing polymer

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