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Superhydrophobic-superoleophilic fabrics were prepared and evaluated for oil–water mixture separation efficiencies. The nano-TiO2 and nano-SiO2 based coatings were done on the surface of the cotton fabric to create nanoscale roughness over the surface which was further modified by low energy material 1, 1, 3, 3-Hexamethyldisilazane (HMDS) and, poly...
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Context 1
... change in contact angle after separation in case SP and TP coating can be attributed to tha fact that PDMS being a polymer is more adhesive to the surface while HMDS is not polymer so it is less adhesive to the surface. Scheme of modification of silica coating by HMDS and PDMs are shown in Figure 9. This scheme is also applied for modification of titania coating. ...
Citations
Introduction
Superhydrophobic materials are considered an ideal method for oil-water separation. However, existing oil-water separation methods have the problem of manufacturing complex and toxic chemical reagents. To address the limitation, we proposed a novel approach to sustainable and efficient oil-water separation using a superhydrophobic membrane based on the Bio Tin oxide nanoparticles (Bio-SnO 2 NPs).
Methods
The study involves synthesizing Bio-SnO 2 NPs from the sunflower leaf extract which was natural and non-toxic and modifying textile fabric with a superhydrophobic coating (S.T.F.). Characterization techniques including SEM, FTIR, and BET analysis are employed to assess the structural and textural properties of the modified membrane.
Results and Discussion
The textile fabric was modified with a superhydrophobic coating (S.T.F.), demonstrating enhanced wettability, oil absorption capacity, and oil-water separation performance. The Bio-SnO 2 NPs exhibited crystalline structures with a length of 90 nm and a diameter of 20 nm, as confirmed by SEM analysis. FTIR results revealed characteristic peaks at 3410 cm ⁻¹ and 642 cm ⁻¹ , indicating the presence of hydroxyl group and Sn-O bonds confirming the successful synthesis of Bio-SnO 2 NPs. BET analysis showed a substantial specific surface area of 413 m ² /g and a pore volume of 0.19 cm ³ /g, emphasizing the textural properties. The FTIR and SEM techniques were used to study the characteristics of the textile fabric before and after modification with the superhydrophobic coat. The S.T.F. exhibited remarkable superhydrophobicity with a water contact angle of 152° and a water sliding angle of 4°. Absorption capacities for coconut oil, diesel, and hexane were found to be 70.4 g/g, 63.5 g/g, and 49.6 g/g, respectively, with excellent cyclic stability. Separation efficiency for hexane, diesel, and coconut oil was found to be 99.5, 97.1%, and 96.3%, respectively, with excellent cyclic stability. Mechanical stability test revealed superhydrophobicity retention even after an abrasion length of 200 mm. The chemical stability test indicated that the superhydrophobicity was maintained in the pH range of 3-11. Moreover, the flux for hexane, diesel, and coconut oil was 9400 L m ⁻² h ⁻¹ , 8800 L m ⁻² h ⁻¹ , and 8100 L m ⁻² h ⁻¹ , respectively, highlighting the membrane’s efficient oil-water separation capabilities. These results collectively position the developed S.T.F. as a promising and sustainable solution for diverse oil-water separation applications.
The operation of easily erected structures made of flammable textiles encourages the use of fire protection, as the operation may ignite tarpaulin fabric, which is a flammable material. Therefore, studies aimed at determining the patterns of formation of an elastic layer of fire-retardant coating on fabrics with a composition based on mixtures of organic and inorganic substances, characterized by the necessary technological properties, are relevant. The paper presents the results of studies of free surface energy, as well as its components (polar and dispersed) for tarpaulin fabric and methods of its change when using a fire-retardant coating. A drop of coating was applied to the sample with a pipette during the test. After reaching the equilibrium drops, its height and diameter were determined with a microscope. The sequences of polarity change and their relationship with the main component of the fabric after the formation of the flame retardant coating, which are consistent with the structural and functional features of the tarpaulin fabric. The resulting fabric is characterized by a reduced property of water absorption, as the free surface energy changes 2.3 times and the polarity 2 times, which is associated with a decrease in the surface tension of the coating. Given the above, it was found that the polarity of the canvas fabric is close to the polarity of the flame retardant coating, which is difficult to wet the material. Instead, the addition of a foaming agent reduces the polarity of the coating and increases the wettability, which allows you to effectively process the canvas fabric. Thus, when applying a comprehensive approach to the study of wettability, polarity, interfacial tension, you can choose stable technologies for new products from fire-retardant fabric and expand their scope.
