Усиление гидрофобных свойств структур ZnO золотым покрытием

The effect of enhancement the hydrophobic properties of the ensemble of micro- and nanostructures ZnO as a result of coating with gold was discovered. For the first time, it has been shown that coating the ensemble with a micro- and nanoparticle ZnO layer of gold leads to a sharp increase in the wetting edge angle from 145 to 168 ° (water drop volume 5 mm3) and a decrease in the hydrophobicity/hydrophilicity transition time under ultraviolet irradiation. Keywords: ZnO, gold, superhydrophobic.

Amphipathic Engineering of Magnetic Composites Reinforced with Ion-Copolymers-Activated Protein-Bioconjugate Functionalized Surface

Structurally stable, multifunctional ion-copolymer composites with enhanced ionic, hydrophilic and hydrophobic properties are developed utilizing multimodal materials. These hyperbranched polymeric composites function as strong supports in multifunctional applications. The integration...

Hydrophobic Properties of CuO Thin Films Obtained by Sol-Gel Spin Coating Technique-Annealing Temperature Effect

The adhesive characteristics of sol-gel copper oxide (CuO) film surfaces at annealing temperatures ranging from 350 to 550°C were examined in this work. Hydrophobic properties of these oxide film surfaces were studied by contact angle measurements. The surface energy was calculated from contact angle data using harmonic mean method. The structural, morphological and chemical analysis of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). The increase in annealing temperature induces a reduction in the hydrophilic properties of the films (adhesive properties). The rise in the hydrophobicity of the CuO surface has been claimed to be explained by a change in interfacial tension. The FTIR spectroscopy analysis revealed that the increase in the annealing temperature eliminates activated neutral species (hydroxyl groups) reacting with the surface of the sample responsible for the wettability. SEM analysis showed that the morphology of the samples is nanostructured containing agglomerates of various forms, a few hundred nanometers in size, randomly dispersed across the surface. The enhanced roughness of the produced film is primarily responsible for the increased hydrophobicity of the films. The XRD data reveal that the films are highly textured and that increasing the annealing temperature induces better layer crystallization and confirms the development of copper oxide CuO.

Comparative Study of Lightweight Cementitious Composite Reinforced with Different Fibre Types and the Effect of Silane-Based Admixture

This study aims to develop a type of fine-grained lightweight concrete, also known as lightweight cementitious composite (LCC), containing perlite microsphere (PM) and fibres with enhanced impermeability. The effect of polypropylene (PP), polyvinyl alcohol (PVA), and basalt fibres on the fresh and hardened properties of LCC was investigated. Besides, silane-based water repellent admixture was incorporated to reduce the water absorption and enhance the hydrophobicity of LCC. The dry densities of LCC developed were in the range of 912–985 kg/m3. PP fibres have lesser influence on the strengths of LCC. However, PVA fibres enhanced the strength of LCC by up to 35.2% and 28% in the compressive strength and flexural strength, respectively, while the basalt fibres increased both strengths up to 30.1% and 43.5%, respectively. By considering the overall performance, LCC with 0.5% PVA fibres has achieved a good balance in workability and strength. Additionally, silane-based water repellent admixture had an excellent effect in reducing the water absorption and improving the hydrophobicity of LCC. By incorporating 1% of silane-based water repellent admixture, the LCC with 0.5% PVA fibres obtained water-resistant properties with the softening coefficient of 0.85 and water contact angle of 128.2°. In conclusion, a combination of PVA-LCC with 1% waterproofing admixture showed the best performance in terms of mechanical strength as well as hydrophobic properties and had the potential to be used in the fabrication of concrete façade.

Composition based on one-component polyurethane modified with tetrapropoxysilane

The questions of interaction of one-component polyurethane and organosilicon compound from the group of alkoxysilanes - tetrapropoxysilane are considered. The composition is intended to obtain a hydrophobic coating with improved performance properties to protect building structures from the effects of technogenic and natural factors. The mechanisms of interaction of one-component polyurethane with tetrapropoxysilane have been studied using spectroscopy. The product of the interaction of the polymer and tetrapropoxysilane is a three-dimensionally crosslinked polymer in which polyurethane macromolecules are crosslinked by organosilicon molecules. The chemical reaction is based on the mechanism of interaction of isocyanate groups with reactive groups of alkoxysilane. The effect of the modifier on the surface structure of the cured coating was studied using a microscope. The contact angle of wetting of the modified and unmodified composition is determined, and the concentration of tetrapropoxysilane at which the coating acquires hydrophobic properties is determined. The effect of tetrapropoxysilane on the adhesive characteristics of the polymer composition has been studied. The change in the hardness of the composition at various concentrations of alkoxysilane was studied. Chemical modification of polyurethane allows you to vary its properties in the desired direction without deteriorating its other characteristics.