The possibility to obtain hollow particles using silica sol as a precursor of a silica shell at different pH values of a D4 emulsion in water is studied. It is shown that the yield of particles, their structure and sizes strongly depend on the pH value.

This report is devoted to the investigation of the emulsion polymerization of methyl methacrylate in the presence of PEGylated hyperbranched polymethylethoxysiloxane as an emulsifier. It is shown that its use in the amount of 1–5 wt % affords stable 25–50% poly(methyl methacrylate) dispersions with the controlled particle sizes from 300 to 800 nm and a narrow particle size distribution.

A number of thioether-containing zirconium siloxanes, differing in their composition and metal atom shielding degree with a siloxy substituent, were synthesized and characterized. Synthesis of such compounds made it possible to evaluate the effect of sulfur atoms’ presence in the cured compositions on their dielectric properties, as well as to evaluate their curing ability and influence on mechanical characteristics compared to the sulfur-free analogs obtained earlier. Studying a wide range of compositions differing in their content and ratio of metallosiloxane and silica components revealed that such systems are still typical dielectrics. At the same time, the introduction of thioether groups can provide increased dielectric constant and conductivity in comparison with previously obtained sulfur-free similar compositions in the <102 Hz frequency range (dielectric constant up to ~10–30 at frequency range 1–10 Hz). As before, the dielectric parameters increase is directly determined by the silica component proportion in the cured material. It is also shown that varying sulfur-containing zirconium siloxanes structure and functionality and its combination with previously obtained sulfur–free analogs, along with varying the functionality and rubber chain length, can be an effective tool for changing the dielectric and mechanical material parameters in a wide range (tensile strength 0.5–7 Mpa, elastic deformation 2–300%), which determine the prospects for the use of such cured systems as dielectric elastomers for various purposes.

Aerogels are a class of materials that have gained increasing attention over the past several decades due to their exceptional physical and chemical properties. These materials are highly porous, with a low density and high surface area, allowing for applications such as insulation, catalysis, and energy storage. However, traditional aerogels, such as pure silica aerogels, suffer from brittleness and fragility, which limit their usefulness in many applications. Herein, we have addressed this problem by using organosilicon compounds, namely polymethylsilsesquioxane derivatives, for the synthesis of aerogel-like materials. Specifically, we have developed a novel approach involving surfactant-free synthesis of microcapsules from partially PEGylated hyperbranched polymethylethoxysiloxane. Due to the highly diphilic nature of these compounds, they readily concentrate at the oil/water interface in aqueous emulsions encapsulating oil droplets. During the subsequent condensation, the organosilicon precursor is consumed for hexane encapsulation (yielding hollow microcapsules) followed by the formation of a continuous condensed phase. Concurrently, methyl groups ensure the hydrophobicity of the resulting materials, which eliminates the need of using additional reagents for their hydrophobization.

Silica hollow spheres with a diameter of 100–300 nm and a shell thickness of 8±2 nm were synthesized using a self-templating amphiphilic polymeric precursor, i.e., poly(ethylene glycol)-substituted hyperbranched polyethoxysiloxane. Their elastic properties were addressed with a high-frequency AFM indentation method based on the PeakForce QNM (quantitative nanomechanical mapping) mode enabling simultaneous visualization of the surface morphology and high-resolution mapping of the mechanical properties. The factors affecting the accuracy of the mechanical measurements such as a local slope of the particle surface, deformation of the silica hollow particles by a solid substrate, shell thickness variation, and applied force range were analysed. The Young’s modulus of the shell material was evaluated as E=26±7 GPa independent of the applied force in the elastic regime of deformations. Beyond the elastic regime, the buckling instability was observed revealing a non-linear force–deformation response with a hysteresis between the loading and unloading force–distance curves and irreversible deformation of the shell at high applied forces. Thus, it was demonstrated that PeakForce QNM mode can be used for quantitative measurements of the elastic properties of submicon-sized silica hollow particles with nano-size shell thickness, as well as for estimation of the buckling behaviour beyond the elastic regime of shell deformations.

The dielectric and mechanical properties of a wide range of polydimethylsiloxane-based compositions filled with silica component and cured with various metallosiloxanes have been studied. It is shown that the resulting systems are typical dielectrics. Silica component introduction in combination with the metal-siloxane network formation in the material can significantly increase its dielectric permittivity and conductivity in the frequency range <10(2) Hz compared to commercial silicon compounds and pure PDMS. It is found that varying the metallosiloxane structure and composition and the degree of silica filling are effective tools for changing the dielectric parameters of the material - up to similar to 5-10 at 1-10 Hz. By varying the functionality and length of the rubber chain, as well as the curing rate, it is possible to vary the mechanical properties of the material within a wide range - 2-10 MPa strength and elongation up to 500% with the pure elastomeric properties up to 200%. This approach to the formation of material opens up prospects for using such cured systems as dielectric elastomers for special applications such as flexible capacitive sensors or actuators for medical and robotic applications.

The properties of quartz flour, glass balls, and basalt powder as fillers of an epoxy-anhydride compound are studied, and the values of thermal conductivity of filler powders obtained by the probe method on an MIT-1 device according to GOST 30256 are presented. The rheological properties of the components of compounds A and B along with the corresponding mixed compositions on an MCR-92 device are studied. The solidified compounds are characterized by the methods of thermogravimetry and differential scanning calorimetry using an STA 449F3 Jupiter (NETZSCH) device. Using a Fluke PM 6303A RLC meter, the data on the frequency dependence of electrical resistance and the physical and mechanical properties of compounds using a Shimadzu AGSH tension testing machine are obtained. It is shown that the type of the filler determines the properties and formation of the polymer–filler interface as one of the key components of the composite material. The data on the effect of the type of fillers on the operational properties of molding compounds are obtained.

MQ resins have been prepared in acetic acid as an active medium from dimethylphenyl- or methyldiphenylethoxy-silane as the M-components and tetraethoxysilane as the Q-component. All prepared samples with M/Q ratios of 1:1, 1:1.5, 1:2, 1:3, and 1:4 were well soluble in organic solvents like toluene and THF. Compared to MQ resins with trimethylsilyl group as the M-component, the new MQ resins with phenyl substituents may possess improved compatibility to thermoplastic polymers, rubbers and coating formulations.

Hollow silica microspheres have been obtained in a surfactantfree templating process at neutral pH from silica sol of 2–10nm globular organic–inorganic silica particles with exposed hydrophobic siloxane part as well as hydrophilic reactive silanol groups. Due to small diffusion coefficient and amphiphilic nature, the sol particles stabilize an oil–water interface quickly. Initially they assemble via noncovalent interaction into a stable shell and then condense covalently, with fast initial stabilization/dispersion of oil–water emulsion improving the control and simplifying the microsphere formation process.

The influence of composition of nanocomposites composed of a polymer matrix and a functional nanofiller—carbon nanotubes (CNTs)—on the conductive, hydrophobic, water-repellent, and adhesive properties of relevant coatings is studied in this work. Coatings based on organofluorine and organosilicon matrices were produced using native CNTs and CNTs functionalized by the alkyl groups. To elucidate the effect of composition of a coating on its functional properties, both the filler concentration at a constant matrix content and the matrix concentration at a constant amount of CNTs were varied. It is found that the surface resistance of coating with a CNT content of 10 to 20% when using the organofluorine matrix is much higher (from 272.5 to 16.07 Ω kV–1) than for coatings based on the organosilicon polymer (from 17.52 to 11.15 Ω kV–1). Probing the relief and structure of coatings reveals that self-organization of carbon nanotubes in a polymer allows one to achieve the surface roughness at both the macro- and nanoscales, increasing the edge angle of surface wetting by water from 92.5° to 135.8° for samples based on the organofluorine polymer and from 113.5° to 144° for samples with the organosilicon matrix. The water drop roll-off angles of these coatings cover a range from 60.2° to 1°.

A procedure was suggested for preparing highly hydrophobic conducting coatings based on fluoropolymers with carbon nanotubes of two types: Taunit-MD and carbon nanotubes functionalized with alkyl groups. The surface resistance, contact angle, sliding angle, and surface roughness were measured; structural features of the nanocomposites were studied. The properties of the coatings obtained depend on the concentration and type of the carbon nanotubes used. Introduction of functionalized carbon nanotubes into a fluoropolymer matrix allows preparation of coatings with higher values of the sliding angle and electrical resistance. The contact angle and sliding angle depend on the surface roughness and structure in different fashions.

Preparation of superhydrophobic conducting coatings based on silicone matrix and two types of carbon nanotubes, native and modified with alkyl groups, is described. The amount of carbon nanotubes per unit surface area was kept constant in all the samples, whereas the content of the polymer matrix was varied. The electrical conductivity, contact angle, and sliding angle were measured. The structure of the coatings was studied with an optical profilometer and a scanning electron microscope. The largest contact angle was 158.4° for the sample with 50 wt % content of native carbon nanotubes. For the samples with more than 20 wt % content of carbon nanotubes of both types, the sliding angle was less than 1°. Changes in the micro- and nanostructure of the coatings, observed with variation of the content of the polymer matrix in the samples, were studied. The relationship between the structural changes, on the one hand, and hydrophobic and water sliding properties of the conducting coatings, on the other hand, was demonstrated.

It has been shown that coatings based on polydimethylsiloxane and tris (methyldiethoxysiloxy) iron have the ability to thermoinitiate self-healing. The effect of MQ-resins on the healing properties of this coating