A new approach to the formation of omniphobic coatings with a reduced content of fluorocarbon radicals has been proposed. The synthesis of vinyl pivalate–perfluorohexylethyl methacrylate copolymers has been first performed via radical polymerization with the use of supercritical CO2 as a solvent. The solubility of copolymers and also the hydrophobic and oleophobic properties of related coatings deposited from solutions in supercritical CO2 on fabrics have been studied. The coatings are characterized by a uniform morphology and an improved adhesion to fibers, which is of great practical interest.

It has been shown that the pretreatment of Celgard polyolefin membranes in the presence of peroxycarbonic acid, which is formed upon saturation of a hydrogen peroxide solution with carbon dioxide under high pressure, improves the characteristics of composites that are obtained on their basis by depositing a polydopamine layer via oxidative polymerization. As compared with the initial matrices that have not been subjected to the pretreatment, the pretreated matrices with the deposited polydopamine layer advantageously combine better wettability with polar media and an increased ion transport selectivity imparted to them in combination with the preserved high ionic conductivity. This effect is achieved due to a decrease in the effective pore diameter. The revealed positive effect of the pretreatment may be related to the oxidative activity of peroxycarbonic acid, which gives rise to the formation of anchor functional groups on the matrix surface. Apparently, these groups facilitate subsequent uniform deposition of polydopamine in all matrix regions, including deep and fine pores due to the high pressure applied.

Радикальной полимеризацией в среде сверхкритического диоксида углерода синтезированы гребнеобразные сополимеры перфторгексилэтилметакрилата и метакрилоксипропил-терминированного полидиметилсилоксана, исследована растворимость сополимеров в сверхкритическом диоксиде углерода, изучены гидрофобные свойства тонких пленок, получаемых осаждением сополимеров на подложки из растворов в трифтортрихлорэтане и сверхкритическом диоксиде углерода. По результатам измерения краевых углов смачивания водой и диметилсульфоксидом рассчитана удельная свободная поверхностная энергия формируемых пленок. Показано, что тонкие пленки сополимеров имеют более низкую поверхностную энергию и характеризуются меньшим гистерезисом краевого угла смачивания водой, чем пленки гомополимера поли(перфторгексилэтилметакрилата). Проведено сравнительное тестирование покрытий на основе гомополимера и сополимера, наносимых из растворов в сверхкритическом диоксиде углерода на поверхность нейлоновых тканей. Установлено, что ткани с покрытием на основе сополимера имеют в среднем более высокие краевые углы смачивания водой.

A method for synthesizing platinum nanoparticles on a dispersed substrate using supercritical carbon dioxide was applied on substrates of various chemical natures: silicon carbide, titanium nitride, and tin dioxide. On all the substrates, materials with narrow uniform platinum nanoparticle size distributions were obtained. The platinum nanoparticle size distribution on each of the substrates was studied. It was shown that the platinum particle sizes are within a narrow range with an average particle size of about 3 nm and scarcely dependent on the chemical nature of the substrate.