Cyclodextrin-Polymethylsilsesquioxane Combined System as a Perspective Iron Delivery System for Oral Administration.

Anemia is a global health problem that affects both adults and children, but treatment is hampered by serious side effects, primarily associated with the gastrointestinal tract with oral administration of drugs. In this study, we aimed to develop an oral form of iron compounds using polymethylsilsesquioxane hydrogels. To boost loading efficiency and prolong release, the iron compounds (FeCl and ferrous D-Gluconate) are incorporated into a guest-host complex with 2-hydroxypropyl-beta-cyclodextrin.

Synthesis of Vinyl-Containing Polydimethylsiloxane in An Active Medium.

This research deals with the synthesis of copoly(methylvinyl)(dimethyl)siloxanes by the copolycondensation of dimethyldiethoxy- and methylvinyldimethoxysilane in an active medium, followed by thermal condensation in a vacuum. We achieved a range of copolymers exhibiting finely tuned molecular weights spanning between 1500 and 20,000 with regulated functional methylvinylsiloxane units. Analysis of the microstructure showed that the copolymerization predominantly formed products demonstrating a random distribution of units (R~1).

Aerogel-Like Material Based on PEGylated Hyperbranched Polymethylethoxysiloxane.

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.

Thioether-Containing Zirconium(Alkoxy)Siloxanes: Synthesis and Study of Dielectric and Mechanical Properties of Silica-Filled Polydimethylsiloxane Compositions Cured by Them.

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.

Pervaporation and Gas Separation Properties of High-Molecular Ladder-like Polyphenylsilsesquioxanes.

This paper presents the results of studies on the pervaporation properties (for benzene/hexane mixtures) and gas permeability (for He, H, N, O, CO, CH, CH, and CH) of ladder-like polyphenylsesquioxanes (L-PPSQ) with improved physical and chemical properties. These polymers were obtained by condensation of -tetraphenylcyclotetrasiloxanetetraol in ammonia medium. The structure of L-PPSQ was fully confirmed by a combination of physicochemical analysis methods: H, Si NMR, IR spectroscopy, HPLC, powder XRD, and viscometry in solution.

Quantitative Elasticity Mapping of Submicron Silica Hollow Particles by PeakForce QNM AFM Mode.

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.

Tetrachromophoric Derivatives of Dibenzoylmethanatoboron Difluoride Based on Stereoregular Cyclotetrasiloxanes: Synthesis and Properties.

A series of new tetrachromophoric systems based on stereoregular tetracyclosiloxanes and dibenzoylmethanatoboron difluoride derivatives have been synthesized and characterized by a complex of physicochemical methods. The photophysical properties of the synthesized compounds are studied by electronic absorption, steady-state, and time-resolved fluorescence spectroscopy. In the synthesized compounds, four dibenzoylmethanatoboron difluoride (DBMBF)-based fluorophores are in an all-cis arrangement with respect to a cyclotetrasiloxane scaffold.

Synthesis of Siloxane Derivatives of Phenylboronic Acids of Different Structures.

The synthesis of a storage-stable organosilicon modifier with a dioxaborolane-protecting group is described. Its high reactivity and selective anti-Markovnikov addition in hydrosilylation reactions to afford siloxanes of various structures are shown. The possibility of deprotection of both the initial modifier and its siloxane derivatives under mild conditions using water in yields up to 96% is demonstrated.

Hybrid Materials with Antimicrobial Properties Based on Hyperbranched Polyaminopropylalkoxysiloxanes Embedded with Ag Nanoparticles.

New hybrid materials based on Ag nanoparticles stabilized by a polyaminopropylalkoxysiloxane hyperbranched polymer matrix were prepared. The Ag nanoparticles were synthesized in 2-propanol by metal vapor synthesis (MVS) and incorporated into the polymer matrix using metal-containing organosol. MVS is based on the interaction of extremely reactive atomic metals formed by evaporation in high vacuum (10-10 Torr) with organic substances during their co-condensation on the cooled walls of a reaction vessel.

Synthesis of Multifunctional Oligomethylsilsesquioxanes by Catalyst-Free Hydrolytic Polycondensation of Methyltrimethoxysilane under Microwave Radiation.

The catalyst-free hydrolytic polycondensation of methyltrimethoxysilane under microwave radiation has been studied. The effect of molar ratios of the reagents (MTMS/HO = 1/0.5-1/9), radiation power (20-300 W), temperature (30-50 °C) and duration of exposure (2.

True Molecular Composites: Unusual Structure and Properties of PDMS-MQ Resin Blends.

Poly(dimethyl siloxane)-MQ rubber molecular composites are easy to prepare, as it does not require a heterophase mixing of ingredients. They are characterized by perfect homogeneity, so they are very promising as rubber materials with controllable functional characteristics. The manuscript reveals that MQ resin particles can significantly, more than by two orders of magnitude, enhance the mechanical properties of poly(dimethyl siloxane), and, as fillers, they are not inferior to aerosils.

Ratiometric Singlet Oxygen Sensor Based on BODIPY-DPA Dyad.

Compounds sensitive to reactive oxygen species are widely used in the study of processes in living cells and in the development of therapeutic agents for photodynamic therapy. In the present work, we have synthesized a dyad in which the BODIPY dye is chemically bound to 9,10-diphenylanthracene (DPA). Here, DPA acts as a specific sensor of singlet oxygen and BODIPY as a reference dye.

Controllable Synthesis of Hybrid Dendrimers Composed of a Carbosilane Core and an Aromatic Shell: Does Size Matter?

The controllable synthesis of novel hybrid dendrimers composed of flexible and rigid components was accomplished via effective Cu-catalyzed azide-alkyne cycloaddition ("click") reaction between azide-functionalized carbosilane cores of two generations and monoethynyl-substituted hexaphenylbenzene dendron. A comprehensive analysis of the thermal and phase behavior of dendrimers allows us to detect a similar performance of dendrimers of both generations which, in our opinion, can be due to the similar ratio of rigid and flexible blocks in the dendrimers regardless the generation of carbosilane cores. The propensity to crystallization and ordering after the annealing procedure was confirmed by DSC and SWAXS.

Chemical Recycling of High-Molecular-Weight Organosilicon Compounds in Supercritical Fluids.

The main known patterns of thermal and/or catalytic destruction of high-molecular-weight organosilicon compounds are considered from the viewpoint of the prospects for processing their wastes. The advantages of using supercritical fluids in plastic recycling are outlined. They are related to a high diffusion rate, efficient extraction of degradation products, the dependence of solvent properties on pressure and temperature, etc.

Polydimethylsiloxanes with Grafted Dibenzoylmethanatoboron Difluoride: Synthesis and Properties.

A method for the preparation of polydimethylsiloxanes with grafted methoxy-substituted dibenzoylmethanatoboron difluoride has been described. The structures of prepared polymers were confirmed using NMR, IR spectroscopy and gel permeation chromatography methods. Their thermal properties were investigated using thermal gravimetric analysis, differential scanning calorimetry and thermomechanical analysis.

Polyborosiloxanes (PBS): Evolution of Approaches to the Synthesis and the Prospects of Their Application.

The mini-review deals with borosiloxanes as a class of organoelement compounds that comprise Si-O-B bonds, including individual compounds and polymeric structures. The borosiloxanes first synthesized in the 1950s using simple methods demonstrated very unusual properties but were hydrolytically unstable. However, in recent times, synthetic methods have changed significantly, which made it possible to synthesize borosiloxanes that are resistant to external factors, including atmospheric moisture.

Synthesis of Carbosilane and Carbosilane-Siloxane Dendrons Based on Limonene.

In this work, carbosilane dendrons of the first, second, and third generations were obtained on the basis of a natural terpenoid, limonene. Previously, we have shown the possibility of selective hydrosilylation and hydrothiolation of limonene. It is proved that during hydrosilylation, only the isoprenyl double bond reacts, while the cyclohexene double bond does not undergo into the hydrosilylation reaction.

The Use of the Thiol-Ene Addition Click Reaction in the Chemistry of Organosilicon Compounds: An Alternative or a Supplement to the Classical Hydrosilylation?

This review presents the main achievements in the use of the thiol-ene reaction in the chemistry of silicones. Works are considered, starting from monomers and ending with materials.The main advantages and disadvantages of this reaction are demonstrated using various examples.

Chemical Structural Coherence Principle on Polymers for Better Adhesion.

Composite materials are the most variative type of materials employed in almost every task imaginable. In the present study, a synthesis of a novel perfluoroalkyltriethoxysilane is reported to be used in creating composites with polyhexafluoropropylene-one of the most indifferent and adhesion-lacking polymers existing. The mechanism of adhesion of hexafluoropropylene is proved to be due to chemical structural coherence of perfluoroalkyltriethoxysilane to a link of polyhexafluoropropylene chain.

Cross-Linked Luminescent Polymers Based on -Diketone-Modified Polysiloxanes and Organoeuropiumsiloxanes.

Nowadays, luminescent materials attract wide attention due to their valuable characteristics and broad area of potential application. Luminescent silicone-based polymers possess unique properties, such as flexibility, hydrophobicity, thermal and chemical stabilities, etc., which allow them to be utilized in various fields, such as optoelectronics, solid-state lasers, luminescent solar concentrators, sensors, and others.

Ring-Opening Polymerization (ROP) and Catalytic Rearrangement as a Way to Obtain Siloxane Mono- and Telechelics, as Well as Well-Organized Branching Centers: History and Prospects.

PDMS telechelics are important both in industry and in academic research. They are used both in the free state and as part of copolymers and cross-linked materials. At present, the most important, practically used, and well-studied method for the preparation of such PDMS is diorganosiloxane ring-opening polymerization (ROP) in the presence of nucleophilic or electrophilic initiators.

Organosilicone Compounds in Supercritical Carbon Dioxide.

This review considers the key advantages of using supercritical carbon dioxide as a solvent for systems with organosilicon compounds. Organosilicon polymeric materials synthesis as well as the creation and modification of composites based on them are discussed. Polydimethylsiloxane and analogues used as polymerization stabilizers and nucleation promoters in pore formation processes are analyzed as well.

New types of hyperbranched 1,2,3-triazole-alkoxysiloxane functional polymers for metal embedded nanocomposite surface coatings.

In this study, using the "click-chemistry" azide-alkyne cycloaddition reaction, two new types of polymers, namely, water-soluble amine-functional and water-insoluble pyridine-functional hyperbranched 1,2,3-triazoleorganoethoxysiloxane polymers, capable of stabilizing ultra-small silver nanoparticles and efficient for chemical surface modification were synthesized and characterized by H-NMR, C-NMR, Si-NMR and FT-IR spectroscopy, MALDI and GPC. Coordinatively active hetero-organic polymers with a flexible branched polyethoxysiloxane backbone bearing chelating 1,2,3-triazolyl-dimethylamine and -pyridine conjugated functional groups were exploited towards coordination with Ag+ metal ions, and formation and stabilization of narrowly dispersed silver nanoparticles (Ag-NPs) obtained in the process of radiation induced metal ion reduction. The influence of the chemically assisted radiation process on the Ag-NP size and size distribution was investigated.

Star-Shaped Polydimethylsiloxanes with Organocyclotetrasilsesquioxane Branching-Out Centers: Synthesis and Properties.

New non-crystallizable low-dispersity star-shaped polydimethylsiloxanes (PDMS) containing stereoregular -tetra(organo)(dimethylsiloxy)cyclotetrasiloxanes containing methyl-, tolyl- and phenyl-substituents at silicon atoms and the mixture of four stereoisomers of tetra[phenyl(dimethylsiloxy)]cyclotetrasiloxane as the cores were synthesized. Their thermal and viscous properties were studied. All synthesized compounds were characterized by a complex of physicochemical analysis methods: nuclear magnetic resonance (NMR), FT-IR spectroscopy, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), viscometry in solution, rheometry, and Langmuir trough study.

Synthesis of 1,1,3,3,5,5-Hexamethyl-7,7-diorganocyclotetrasiloxanes and Its Copolymers.

This paper reports a method for the synthesis of 1,1,3,3,5,5-hexamethyl-7,7-diorganocyclotetrasiloxanes by the interaction of 1,5-disodiumoxyhexamethylsiloxane with dichlorodiorganosilanes such as methyl-, methylvinyl-, methylphenyl-, diphenyl- and diethyl dichlorosilanes. Depending on the reaction conditions, the preparative yield of the target cyclotetrasiloxanes is 55-75%. Along with mixed cyclotetrasiloxanes, the proposed method leads to the formation of polymers with regular alternation of diorganosylil and dimethylsylil units.