A one-pot synthesis of superparamagnetic nanocomposites via polycondensation of phenylenediamine isomers and 1,1 '-diacetylferrocene in the melt is described. Obtained nanocomposites were characterized by IR spectroscopy, XPS, XRD, EPR, SEM, TGA/DTA, and magnetization curves. The formation of oligomeric azomethines in the melt was accompanied by side hydrothermolysis of 1,1 '-diacetylferrocene, even at 140 degrees C under an argon atmosphere. According to XRD and IR spectroscopy, hydrothermolysis of 1,1 '-diacetylferrocene led to the formation of magnetite nanoparticles with an average size of around 10 nm, and a mixture of diacetyldicyclopentadiene isomers, presumably acting as crosslinking agents via reaction with terminal groups of oligomeric azomethines. XPS and IR spectroscopy demonstrated the formation of C=N bonds with retention of a fraction of unreacted keto and amino groups. The possibility of C=N bond formation was established in experiments on low-molecular-weight model compounds, and the synthesized monoimines and diimines of 1,1 '-diacetylferrocene and aniline were characterized by NMR, IR spectroscopy, and X-ray diffraction. XPS revealed the presence of Fe3+ on the surface of the nanocomposites, which, according to EPR spectroscopy and magnetization curves, exhibit superparamagnetism. The obtained nanocomposites are promising materials for cores of high-frequency inductors, as well as other devices requiring magnetization without energy dissipation due to hysteresis.

Seven new and one previously described pyrazolylimine complex NiBr2 with aryl substituents exhibiting different electronic effects on the imine carbon atom were synthesized and characterized. It was shown that the obtained compounds are effective catalysts for ethylene polymerization in the presence of diethylaluminum chloride (DEAC).The influence of the electronic properties of the R substituents on the catalytic performance of the complexes was systematically investigated. A clear correlation between ligand electron-donating or -withdrawing character and both polymer molecular weight and catalytic activity was observed, providing insight into the electronic factors governing the efficiency of these nickel-based systems.

Hybrid heterostructure (HHS) with alternating monolayer sheets of molybdenum disulfide (MoS2) and amino acid L-arginine (Arg) hydrate with Mo: Arg molar ration 1:0.1 was synthesized by exfoliation-restacking of LiMoS2 precursor. The phase composition, atomic structure and bonding interactions within HHS were investigated by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and density functional theory (DFT) calculations. The obtained results showed that a wide network of hydrogen bonds, with particularly strong NH∙∙∙S and HO∙∙∙S ones, combines the sulfide and organic sheets into a layered hybrid system with intersheet periodicity of 10.04 Å. The sulfide sheets of HHS were shown to be highly enriched (up to 70

The paper reports a facile way for noncovalent functionalization of 1T-MoS2 with L-lysine (Lys) monolayers. The structure of the resultant hybrid compound was revealed by the powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, absorption spectroscopy and density functional theory (DFT) calculations study. A significant strength of the in-layer organic and organic-inorganic hydrogen bonding amounting to 24.6 and 29.9 kcal per mole of Lys, respectively, was found to hold the hydrated Lys molecules arranged in 2D chains and keep these chains tightly bound to the MoS2 sheets. The MoS2 hybridization with Lys significantly rises the upper temperature stability limit of 1T-MoS2 polymorph, which possesses the remarkable photothermal properties in near infra-red (NIR) region. The hybrid structure demonstrates excellent photothermal light-to-heat conversion efficiency reaching 49.5% upon 808 nm laser irradiation and higher thermal durability than unmodified 1T-MoS2.

A representative series of functional branched metallosiloxane oligomers was used to obtain polydimethylsiloxane-based composites highly filled with a metallosiloxane component. Physical and mechanical characteristics of compositions obtained strongly depends on metallosiloxane structure and composition. It is shown that it is possible to regulate the strength and elastic properties of the systems under consideration within wide limits, as well as to influence the morphology of the material. The resulting materials are rather thermo-oxidatively stable and can also maintain high mobility of polydimethylsiloxane chains.

A simple method of obtaining composites based on fullerene and silver nanoparticles (AgNPs) has been proposed. Non-covalent water-dispersible composites were prepared by mixing a water solution of polymer-stabilized AgNPs and a solution of pristine fullerene C60 in N-methylpyrrolidone (NMP), followed by exhaustive dialysis against water. Alternating copolymers of dicarboxylic acid were used as stabilizing copolymers in the complexes of AgNPs: poly(styrene-alt-maleic acid) - SM, poly(N-vinyl-2-pyrrolidone-alt-maleic acid) - VM or poly(ethylene-alt-maleic acid) - EM. A 5-6-fold molar excess of copolymer/AgNP complexes SM/Ag0 or VM/Ag0 and approximately 10-fold excess of EM/Ag0 were used relative to C60 (moles of copolymers corresponded to AgNPs containing dimer units of copolymers). The volume of the aqueous phase when preparing composites was correlated with the organic phase as 1 to 1-1.3. The physical and optical properties of the preparations were characterized by UV-vis and FTIR spectroscopy, DLS, TGA, TEM and XPS. It has been shown that fullerene is included in the composites in solvated form. The AgNP content in the composites was 22-34, and that of C60 is 20-28 wt%. The dry composites were found to be dispersible in water, but were practically insoluble and did not dissociate in nonpolar solvents and NMP. It has been shown that C60 significantly inhibits the oxidative degradation of AgNPs in the composites and increases the antifungal activity of the preparations against Candida albicans.

The development of well-designed anisotropically ordered photoactive liquid-crystalline polymers has potential in the development of a number of areas related to high-tech light-responsive materials and devices, including photonics, optical switching, image storage, soft actuators, etc. The synthesis and characterization of a new type of photoactive linear main chain liquid-crystalline hybrid copolymers with regularly alternating molecular architectures is achieved for the first time through the use of azide-alkyne cycloaddition chemical reactions between a series of alkyne-terminated azobenzene molecules and azide-functional oligo(dimethylsiloxane) telechelics. The present investigation encompasses an array of chemical structures and molecular morphologies, thermodynamic properties, thermotropic liquid-crystalline and photoisomerization behaviors, and the influence of the azo-copolymer molecular composition on the polymers' microstructure, morphologies, and propensity towards thermotropic self-assembly into lamellar spherulitic structures. The kinetics of non-degradative reversible E-Z photoisomerization transitions and the relationship between the molecular composition of the polymers and their photoinduced isomerization behavior were investigated. The morphology and degree of anisotropy of physically cross-linked LCPs fibers prepared by the simple melt spinning method were studied. The results obtained provide important insights into the structure-property relationship of photoactive main chain hybrid azobenzene-siloxane LCPs, which are useful for the design of novel advanced photoactive polymers.

It was shown by EPR spectroscopy that Ti(IV) was gradually reduced to Ti(III) when a titanium(IV) dichloride complex with a saligenin ligand was used as a model pre-catalyst in the presence of (EtnAlCl3–n + Bu2Mg) as an activator. Pre-activation of this complex (by stirring in an inert atmosphere with a half-load of the Al/Mg activator before being introduced into the reactor) significantly (about twofold) enhanced its catalytic activity, up to 4100 kgPE molTi–1 h–1 atm–1. All the synthesized polyethylene samples were linear ultrahigh-molecular-weight polymers (UHMWPEs) with Mv = 1.0–3.5×106 g/mol. This pre-activation technique was further employed to test a series of Al/Mg activators that differed in the nature of their organometallic compounds and in their Al/Mg molar ratio. The test data suggest that the catalytic system under study had active sites with titanium being present mainly in the oxidation state of +3. Most samples of UHMWPE produced with the pre-activated complex proved suitable for solvent-free processing into high-strength oriented films.

New ionic complexes with various metals (Mg2+, titanium in various oxidation states, and iron triad metals) in the 15-crown-5 cavity as a cation and a titaniumcontaining anion have been synthesized. The structure of some synthesized complexes was determined by X-ray diffraction analysis. These compounds, in the presence of the Al/Mg activator {Et2AlCl + Bu2Mg}, catalyze the polymerization of ethylene with the formation of ultrahigh molecular weight polyethylene (UHMWPE) with molecular weights up to 2.56 & sdot;106 Da. Only complexes with a titanium-containing anion showed catalytic activity; its maximum value -4651 kg of PE/mol & sdot;h & sdot;atm was exhibited by the complex [15C5 superset of FeoCl & sdot;2CH3CN]2+[Ti2Cl10]2-. The resulting ultra -high molecular weight polyethylene (Mv to 2.56 center dot 106 Da) can be processed by a solventless method into high-strength (up to 2.45 GPa) and high-modulus (up to 144 GPa) oriented tapes. Most polyethylene samples have a linear structure, with the exception of polymers obtained on Ni/Ti complexes, which have 2-3 branches per 1000 carbon atoms.

A series of poly[dimethyl(methylbenzyl)siloxanes] with different content of the methylbenzylsiloxane fragments have been synthesized. Structure of the polymers has been confirmed by means of 1Н and 29Si NMR spectroscopy. Thermal properties of the polymers have been investigated by means of differential scanning calorimetry and thermogravimetric analysis. It has been found that the copolymer crystallization is suppressed at the content of the methylbenzylsiloxane fragments on the copolymer of 3 mol

A ferrocene-containing oligoorganosiloxane with a number-average degree of polymerization of 8.8 and a number-average molecular weight of 3200 is synthesized by hydrolytic condensation of 3-aminopropyltriethoxysilane followed by chemical modification of the resulting oligomer with acetylferrocene. Its structure is characterized by MALDI-TOF, NMR and IR spectroscopy. 1H NMR spectroscopy shows the predominance of more thermodynamically stable units containing anti-configuration Schiff bases. Using IR spectroscopy as well as experimental determination of surface energy and its polar (acid-base) and dispersion components, the covalent immobilization of ferrocene-containing oligoorganosiloxane on a glass surface after heating at 110 degrees C is shown. The formed coating provides hydrophobization, acid-base indifference of the glass surface and serves as a precursor for the formation of magnetically soft materials after pyrolysis in argon already at 350 degrees C. The main stages of ferrocene-containing oligoorganosiloxane thermal destruction in an inert atmosphere and the formation of a mixture of iron and silicon oxides during its thermal oxidative destruction are established by combination of TGA/DTA, IR spectroscopy and elemental analysis. The proposed approach opens up new possibilities for functionalizing silicates surfaces, creating magnetic glasses, as well as regulating surface energy and its components.

New titanium(+4) and vanadium(+5) 8-oxyquinolinate complexes were synthesized. Their structures were determined by X-ray diffraction. The synthesized compounds catalyze the polymerization of ethylene in the presence of Al/Mg activators, Et2AlCl/Bu2Mg and Et3Al2Cl3/Bu2Mg (up to 3400 kg of PE (mol of [M] h atm)−1), to form ultrahigh-molecular-weight polyethylene with a molecular weight up to 5.3•106 Da. The synthesized compounds are shown to be efficient precatalysts for the synthesis of ethylene-octene copolymers. A high insertion of 1-octene into the copolymer composition, up to 9.5

A series of new homo- and copolymers P1-P6 with the main chains comprised exclusively of benzo [1,2-b:4,5-b'] dithiophene units were synthesized using Stille polycondensation reaction. The optical and electrochemical properties of P1-P6 polymers were studied to estimate the frontier orbitals energies and the Eg values. The obtained data demonstrate the possibility of controlling the electronic properties of polybenzo [1,2-b:4,5-b'] dithiophenes by varying only the structure and combinations of solubilizing alkyl side chains. The polymers P1-P6 were evaluated as hole transport materials in n-i-p perovskite solar cells. The highest efficiency of 18.6 % was delivered by the cells with one of the designed polymers with an optimal combination of alternating monoand dialkylthiophene substituents. The high photovoltaic performance and decent operational stability were achieved using polymer films without any doping, which paves a way to design of inexpensive and scalable dopant-free materials for perovskite solar cells.

A series of new homo- and copolymers P1–P6 with the main chains comprised exclusively of benzo[1,2-b:4,5-b']dithiophene units were synthesized using Stille polycondensation reaction. The optical and electrochemical properties of P1–P6 polymers were studied to estimate the frontier orbitals energies and the Eg values. The obtained data demonstrate the possibility of controlling the electronic properties of polybenzo[1,2-b:4,5-b']dithiophenes by varying only the structure and combinations of solubilizing alkyl side chains. The polymers P1–P6 were evaluated as hole transport materials in n-i-p perovskite solar cells. The highest efficiency of 18.6% was delivered by the cells with one of the designed polymers with an optimal combination of alternating mono- and dialkylthiophene substituents. The high photovoltaic performance and decent operational stability were achieved using polymer films without any doping, which paves a way to design of inexpensive and scalable dopant-free materials for perovskite solar cells.

The synthesis of novel stereoregular carborane-containing phenylcyclosiloxanes (4, 5, 6, 8, and 12 –SiO– units in the ring) has been developed.

This work shows for the first time the influence of the method of introducing Mg compounds into a post-metallocene-type catalytic system on its catalytical performance and the properties of the resulting polymer, and it is concluded that the real catalytic center is heterometallic Ti/Mg complexes. Compares three different approaches to introducing Mg compounds into catalytic systems containing a titanium(IV) dichloride complex with an (O^O)2- type ligand and an organoaluminium compound - the use of Al/Mg co-catalysts, the immobilization of a Ti complex on the surface of anhydrous MgCl2 and in situ preparation of heterometallic Ti/Mg complexes. All three approaches lead to the production of ultra-high molecular weight polyethylene, but systems with externally introduced magnesium chloride showed the lowest productivity. UHMWPE samples synthesized on Ti/Mg precatalysts and conventional OAC are suitable for solvent-free solid-phase processing into high-strength, high-modulus film threads.

Sustained interest in the use of renewable resources for the production of medical materials has stimulated research on bacterial cellulose (BC) and nanocomposites based on it. New Ag-containing nanocomposites were obtained by modifying various forms of BC with Ag nanoparticles prepared by metal–vapor synthesis (MVS). Bacterial cellulose was obtained in the form of films (BCF) and spherical BC beads (SBCB) by the Gluconacetobacter hansenii GH-1/2008 strain under static and dynamic conditions. The Ag nanoparticles synthesized in 2-propanol were incorporated into the polymer matrix using metal-containing organosol. MVS is based on the interaction of extremely reactive atomic metals formed by evaporation in vacuum at a pressure of 10−2 Pa with organic substances during their co-condensation on the cooled walls of a reaction vessel. The composition, structure, and electronic state of the metal in the materials were characterized by transmission and scanning electron microscopy (TEM, SEM), powder X-ray diffraction (XRD), small-angle X-ray scattering (SAXS) and X-ray photoelectron spectroscopy (XPS). Since antimicrobial activity is largely determined by the surface composition, much attention was paid to studying its properties by XPS, a surface-sensitive method, at a sampling depth about 10 nm. C 1s and O 1s spectra were analyzed self-consistently. XPS C 1s spectra of the original and Ag-containing celluloses showed an increase in the intensity of the C-C/C-H groups in the latter, which are associated with carbon shell surrounding metal in Ag nanoparticles (Ag NPs). The size effect observed in Ag 3d spectra evidenced on a large proportion of silver nanoparticles with a size of less than 3 nm in the near-surface region. Ag NPs in the BC films and spherical beads were mainly in the zerovalent state. BC-based nanocomposites with Ag nanoparticles exhibited antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli bacteria and Candida albicans and Aspergillus niger fungi. It was found that AgNPs/SBCB nanocomposites are more active than Ag NPs/BCF samples, especially against Candida albicans and Aspergillus niger fungi. These results increase the possibility of their medical application.

Polynaphthoylenebenzimidazoles containing functional sulfo groups were synthesized by a one-step method in a sulfuric acid medium with oleum. A polymer-analogous transformation of these polymers with aqueous solutions of metal salts (K, Ca, and Cr) was carried out. Their chemical structure was characterized by FTIR, NMR, and elemental analysis. Polymer salt coatings were deposited on QCM sensor surfaces by electron beam-induced vacuum deposition. The morphology of the coatings was characterized by AFM. It was shown that the coatings formed from a series of polymer salts have different adsorption activity in acetaminophen–water solution compared to distilled water. The QCM results indicate that sensor signal correlates with polymer coating thickness, morphology, and its chemical composition.

Five low-dispersity star-shaped polydimethylsiloxanes were synthesized. The macromolecules of the poly-mers contain the same branching-out center, a cis-tetraphenylcyclotetrasilsesquioxane moiety, and the same number of arms, but with different lengths (n = 15, 21, 48, 75, and 123 Si(Me)2O units). Their properties were studied by a set of physicochemical analytical methods. Viscometric studies showed that the macromolecules of the Ph4-15, Ph4-21, Ph4-48, and Ph4-75 polymers are small-sized dense balls both in solution and in melt. DSC studies identified an unusual effect of the cyclic core on the thermal behav-ior of the Ph4-15, Ph4-21, and Ph4-48 polymers. Its incorporation suppresses the crystallization of PDMS-arms (up to n = 48 Si(Me)2O units) at concentrations four times lower than those of known modifiers and does not affect the glass transition temperature (ca.-124 degrees C).(c) 2023 Elsevier B.V. All rights reserved.