КОЛЛОИДНО-ХИМИЧЕСКИЕ СВОЙСТВА КРЕМНИЙОРГАНИЧЕСКИХ ПАВ, ПРИМЕНЯЕМЫХ В СИНТЕЗЕ ПОЛИСТИРОЛЬНЫХ ЛАТЕКСОВ

The synthesis of polymeric suspensions with a narrow particle size distribution is an urgent problem in modern science. The resulting polymeric microspheres are applicable in various fields of chemistry, pharmaceuticals, biology and medicine. In particular, they can be used as carriers of bioligands to create diagnostic test systems. This article presents the results of a study on the colloid-chemical characteristics of water-insoluble fluorinated silicone surfactants and kinetics of the polymerization process in their presence. The results were compared with data from studies on the properties of surfactants of similar structure not containing fluorine atoms in their structure. Studying these substances’ rheology enabled to determine the most suitable surfactants for adsorption forming a strong interfacial layer during the formation of polymermonomer particles during the polymerisation. The ability of fluorinated silicone surfactants to form a stable polymeric slurry was proved during heterophase polymerization of vinyl monomers. The resulting polymeric suspensions were characterized by a narrow particle size distribution and high aggregative stability during the synthesis and in storage.Синтез полимерных суспензий с узким распределением частиц по размерам является актуальной проблемой в современной науке. Полимерные микросферы применимы в различных отраслях химии, фармацевтики, биологии и медицины, в качестве носителей биолигандов при создании диагностических тест-систем. В работе приведены данные по изучению коллоидно-химических характеристик нерастворимых в воде фторированных кремнийорганических поверхностно-активных веществ (ПАВ) и кинетики процесса полимеризации в их присутствии. Изучение реологии данных веществ позволило определить наиболее подходящее ПАВ для формирования прочного межфазного адсорбционного слоя при образовании полимерно-мономерных частиц в процессе полимеризации. Способность фторированных кремнийорганических ПАВ образовывать стабильные полимерные суспензии была доказана при проведении гетерофазной полимеризации виниловых мономеров. Полученные полимерные суспензии характеризовались узким распределением частиц по размерам, а также высокой агрегативной устойчивостью в процессе синтеза и при хранении

Hypogene Speleogenesis in the Piedmont Crimea Range

Intense development of the theory and criteria for identification of hypogenic speleogenesis during the past few years has stimulated re-interpretation of karst phenomena in many regions of the world. Recent research strongly suggests that solution features in the Piedmont Range of the Crimean Mountains, previously believed to be the result of hypergene (epigene) karstification, were in fact formed in a hypogenic environment due to ascending transverse flow in a stratified artesian system. Tectonically, the Piedmont Range of Crimea is an edge of the Scythian Plate, uplifted and partially eroded along the regional fault separating the plate from the folded region of the Crimea Mountains. The Cretaceous and Paleogene sequence dips 5 to 20o to north and north-west, where it plunges beneath a Neogene cover. It is exposed within the Piedmont Range as a series of distinct cuestas generally facing south-east. Karst features are represented by 26 caves and abundant, diverse solution forms at the cuesta escarps. Most of the karst develops in two distinct limestone units of Paleocene (Danian) and Eocene (Lutetian) but some are present in the underlying Maastrichtian unit of Cretaceous. There are strong and systematic evidences that the caves have a hypogenic origin and that most of the solution features along the scarps are remnants of morphologies of hypogenically karstified fractures, the walls of which are now exposed due to block-fall retreat of the scarp faces. The features in various beds demonstrate strong lithostratigraphic control in their distribution and are vertically stacked into transverse complexes. Caves are fracture-controlled, linear, or crude maze clusters, demonstrating the complete suite of morphologies indicative of hypogenic origin. Isolated cavities, expressed in the contemporary scarps as grottoes, niches and as zones of spongework porosity, developed where laterally conductive beds of higher initial porosity were crossed by vertical fractures that once conducted rising fluids from an underlying r

Hypogene Speleogenesis in the Piedmont Crimea Range

Intense development of the theory and criteria for identification of hypogenic speleogenesis during the past few years has stimulated re-interpretation of karst phenomena in many regions of the world. Recent research strongly suggests that solution features in the Piedmont Range of the Crimean Mountains, previously believed to be the result of hypergene (epigene) karstification, were in fact formed in a hypogenic environment due to ascending transverse flow in a stratified artesian system. Tectonically, the Piedmont Range of Crimea is an edge of the Scythian Plate, uplifted and partially eroded along the regional fault separating the plate from the folded region of the Crimea Mountains. The Cretaceous and Paleogene sequence dips 5 to 20o to north and north-west, where it plunges beneath a Neogene cover. It is exposed within the Piedmont Range as a series of distinct cuestas generally facing south-east. Karst features are represented by 26 caves and abundant, diverse solution forms at the cuesta escarps. Most of the karst develops in two distinct limestone units of Paleocene (Danian) and Eocene (Lutetian) but some are present in the underlying Maastrichtian unit of Cretaceous. There are strong and systematic evidences that the caves have a hypogenic origin and that most of the solution features along the scarps are remnants of morphologies of hypogenically karstified fractures, the walls of which are now exposed due to block-fall retreat of the scarp faces. The features in various beds demonstrate strong lithostratigraphic control in their distribution and are vertically stacked into transverse complexes. Caves are fracture-controlled, linear, or crude maze clusters, demonstrating the complete suite of morphologies indicative of hypogenic origin. Isolated cavities, expressed in the contemporary scarps as grottoes, niches and as zones of spongework porosity, developed where laterally conductive beds of higher initial porosity were crossed by vertical fractures that once conducted rising fluids from an underlying r

Hydrothermal epitaxy growth of self-organized vanadium dioxide 3D structures with metal–insulator transition and THz transmission switch properties

The hydrothermal method is the most effective approach for the synthesis of VO2 metastable polymorphs with unique powder crystallite morphology. In this work, we expanded the capabilities of this method, directing it to the growth of oriented crystallites in self-organized systems on single crystal substrates. According to our investigations, a large variety of 3D structures of vanadium dioxide can be obtained using one single crystal substrate r-sapphire by fine tuning of synthesis parameters. The orientation growth of six-pointed vanadium dioxide crystallites fits into an epitaxial growth model describing unit cell relations between the VO2(M1) film and r-sapphire substrate. We describe the process of VO2(M1) phase stabilization in the films and the changes of resistivity and terahertz transparency of the films based on the metal–insulator transition (MIT)

COLLOID-CHEMICAL PROPERTIES OF SILICONE SURFACTANTS USED IN THE SYNTHESIS OF POLYSTYRENE LATEXES

The synthesis of polymeric suspensions with a narrow particle size distribution is an urgent problem in modern science. The resulting polymeric microspheres are applicable in various fields of chemistry, pharmaceuticals, biology and medicine. In particular, they can be used as carriers of bioligands to create diagnostic test systems. This article presents the results of a study on the colloid-chemical characteristics of water-insoluble fluorinated silicone surfactants and kinetics of the polymerization process in their presence. The results were compared with data from studies on the properties of surfactants of similar structure not containing fluorine atoms in their structure. Studying these substances’ rheology enabled to determine the most suitable surfactants for adsorption forming a strong interfacial layer during the formation of polymermonomer particles during the polymerisation. The ability of fluorinated silicone surfactants to form a stable polymeric slurry was proved during heterophase polymerization of vinyl monomers. The resulting polymeric suspensions were characterized by a narrow particle size distribution and high aggregative stability during the synthesis and in storage

Novel fused tetrathiocines as antivirals that target the nucleocapsid zinc finger containing protein of the feline immunodeficiency virus (FIV) as a model of HIV infection

A novel series of fused tetrathiocines were prepared for evaluation of activity against the nucleocapsid protein of the feline immunodeficiency virus (FIV) in an in vitro cell culture approach. The results demonstrated that the compounds display potent nanomolar activity and low toxicity against this key model of HIV infection