scholarly journals Wetting properties of the sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and polyoxyethylene (23) lauryl ether (Brij 35) binary mixtures in the poly(tetrafluoroethylene)-solution-air system

2015 ◽  
Vol 70 (1) ◽  
Author(s):  
Joanna Krawczyk
Keyword(s):  
Surface Tension ◽  
Aqueous Solutions ◽  
Binary Mixtures ◽  
Critical Surface ◽  
Surface Wetting ◽  
Critical Surface Tension ◽  
Wetting Properties ◽  
Ptfe Surface ◽  
Brij 35 ◽  
Lauryl Ether

AbstractWettability of poly(tetrafluoroethylene) (PTFE) by aqueous solutions of binary mixtures composed of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) with polyoxyethylene (23) lauryl ether (Brij 35) was considered on the basis of the measured values of contact angle and surface tension. It was shown that the value of the critical surface tension of PTFE surface wetting at the studied system (23.5 mN/m), does not depend on the concentration and composition of the binary mixtures of studied surfactants in water, and it was higer than the surface tension of PTFE (20.2 mN/m). The best wettability of polytetrafluoroethylene (PTFE) by studied aqueous solutions of binary surfactants mixtures occurs at the mixtures concentration corresponding to the critical micelle concentration of their solutions.

Durability of Coatings Based on Sol Silicate Paint

2019 ◽  
Vol 394 ◽  
pp. 1-4
Author(s):  
Valentina Ivanovna Loganina ◽  
Yerkebulan Bisengalievich Mazhitov ◽  
Yuri Petrovich Skachkov
Keyword(s):  
Surface Tension ◽  
Surface Energy ◽  
Intermolecular Interaction ◽  
Frost Resistance ◽  
Hamaker Constant ◽  
Critical Surface ◽  
Freezing And Thawing ◽  
Critical Surface Tension

The results of the study provide information on the resistance of coatings based on the solof silicate paint in the process of freezing and thawing. It was found, that coatings based on sol silicatepaints are characterized by a higher resistance compared of silicate coatings. It is shown, that thecoatings withstood 50 cycles of alternate freezing and thawing. The surface energy of the coatingswas calculated using the critical surface tension of the fluid at the interface with the solid. Thedispersion contribution in the intermolecular interaction between the particles of the coatings wasestimated. The values of the surface tension of the coatings and the values of the dispersioncomponent of the surface energy of the coatings — the complex Hamaker constant — are calculated.It was revealed, that after testing a decrease in the values of the Hamaker constant is observed. It wasestablished, that after testing for frost resistance, the values of the Hamaker constant for coatingsbased on sol of silicate paint are higher compared to coatings based on silicate paint.

scholarly journals Preparation of Silica Aerogel and Its Adsorption Performance to Organic Molecule

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hong-xin Shi ◽  
Jing-tao Cui ◽  
Hai-min Shen ◽  
Hong-ke Wu
Keyword(s):  
Waste Water ◽  
Surface Tension ◽  
Silica Aerogel ◽  
Critical Surface ◽  
Critical Surface Tension ◽  
Adsorption Performance ◽  
Aqueous Solvent ◽  
Ft Ir ◽  
Gelling Time ◽  
Adsorption Desorption

Hydrophobic and lipophilic silica aerogel was prepared from water-glass by gelling, aging, silylation, and drying under atmospheric pressure and characterized by FT-IR and SEM. The effect of preparation process on aerogel density and the aerogel density on contact angle of water on it were investigated in detail. pH 6 is most beneficial to shorten gelling time and to obtain the lowest density of silica aerogel. Increasing TEOS concentration of aging solution to 25 v% could decrease aerogel density to 0.093 g/cm3. The silica aerogel exhibits good hydrophobicity even though its density is 0.30 g/cm3. There are few changes in their adsorption capacities after 3 cycles of adsorption-desorption. The adsorption performance of the silica aerogel to organic solvent in water is different from in pure solvents. The critical surface tension (γC) of the silica aerogel prepared here is about 30.8 mN/m. If the surface tension of aqueous solvent solution (γ) is greater thanγC, it will wet the aerogel surface partially. Ifγ  ≤  γC, the solution will wet all aerogel surface and be adsorbed well. This work delivers us a method to adsorb solvents from their waste water by adjusting the surface tension of the waste water to lower thanγCof the adsorbent.

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