Hybrid Organic-inorganic Composites Research Articles

Preparation of Photocurable Organic-Inorganic Hybrid Composites for Continuous Manufacturing of 3D-Patterned Abrasive.

Photocurable hybrid organic-inorganic composites were prepared via surface modification and 3D-patterned structures were fabricated by utilizing a continuous roll-to-roll manufacturing strategy. The surfaces of nanocrystals were engineered with a bifunctional ligand that is a 2-carboxyethyl acrylate, which possesses a carboxylic acid moiety at one end and an acrylate functionality moiety at the other end, yielding acrylate-functionalized nanocrystals. Micro-scale 3D patterns (protruding pyramidal shapes with each side measuring 147 μm) were continuously manufactured at a speed of 2.5 m/min via UV curing with a soft engraved mold. The surface properties of the functionalized nanocrystals and their UV curing condition were explored with Fourier transform infrared spectroscopy. The morphology of the 3D film was measured using scanning electron microscopy. A pin-on-disk tribometer measurement revealed an improved interaction between the functionalized particles and resins.

High responsivity self-powered flexible broadband photodetector based on hybrid Selenium-PEDOT:PSS junction

Hybrid organic-inorganic composites offer solution processability and ease to construct opto-electronic devices with diverse functionalities, which are desirable for applications like flexible and printed electronics. Trigonal Selenium (t-Se) has been recently investigated for photodetector application, owing to its inherent superior optical properties such as high absorption coefficient and photoconductivity. However, most of the reported Selenium photodetectors use vapor transport based device fabrication techniques which require controlled environments and face scalability issues. In this work, high-performance photodetector based on Selenium-PEDOT:PSS hybrid junction is demonstrated using a facile sonication assisted mechanical mixing and drop-casting technique. XRD and Raman analysis reveals the existence of Selenium in trigonal crystal structure and FE-SEM images show clustered nanoparticles. Selenium is mixed with PEDOT:PSS to form bulk heterojunction, which enhances the electron-hole pair separation efficiency and results in improved device responsivity. Also, due to the favorable band offset between Selenium and PEDOT:PSS which results in built-in field, the photodetector operates in self-biased mode. The device exhibits broad spectral response in UV–Vis–NIR range with responsivities of 0.56 A/W, 66 mA/W and 1.363 A/W at 315 nm, 620 nm and 820 nm, respectively. Response times of 7.7 s, 9.4 s and 6.4 s and external quantum efficiencies (EQE) of 192.58%, 13.25% and 206.55% are obtained for UV, Vis and NIR spectra respectively. Further to validate the robustness, the device is subjected to multiple bending cycles (∼2500) and minimal degradation in performance is observed. Given the simple device architecture and facile device fabrication scheme, this work would enable promising approach for high performance flexible photodetectors. • Selenium, possesses high absorption co-efficient and high photoconductivity with optical bandgap of 1.2–1.5 eV. • However, t-Se has been less explored for photodetector applications. • This work reports a solution-processed hybrid-heterojunction based on Se-PEDOT:PSS for photodetection. • The detector exhibits spectral response from UV–Vis to NIR and significant performance at zero bias condition.

Performance of Composite Glass-Diarylethene Crystal Photomechanical Actuator Membranes.

Hybrid organic-inorganic composites based on organic photochromic crystals embedded in inorganic templates provide a new approach to photomechanical materials. Diarylethene (DAE) nanowire crystals grown in Al2O3 membranes have exhibited reversible photoinduced bending and lifting [Dong, X., Chem. Mater. 2019, 31, 1016-1022]. In this paper, the hybrid approach is extended to porous SiO2 membranes. Despite the different template material (SiO2 instead of Al2O3) and much larger channels (5 μm diameter instead of 0.2 μm diameter), similar photomechanical behavior is observed for this new class of organic-inorganic hybrid actuators. The ability to reuse individual glass templates across different DAE filling cycles allows us to show that the DAE filling step is crucial for determining the mechanical work done by the bending template. The bending curvature also depends quadratically on the template thickness, in good agreement with theory. The light-induced bending can be repeated for up to 150 cycles without loss of performance, suggesting good fatigue resistance. The results in this paper demonstrate that the hybrid organic-inorganic approach can be extended to other host materials and template geometries. They also suggest that optimizing the organic filling and template thickness could improve the work output by an order of magnitude.

Introduction: biopolymers and biocomposites

Abstract Biopolymers and biocomposites are an exciting class of ubiquitous materials. Interest in these materials has been driven in part by their biocompatibility/biodegradability, sustainability, potentially low-cost, renewability, being environmental benign, among other properties. These fascinating materials come in a range of forms from the DNA and RNA that is essential to life to the cellulose and collagen that mechanically reinforce tissues and as hybrid organic–inorganic composites like teeth. Herein, we summarize some aspects of the two classes of materials biopolymer and biocomposites, exploring specific examples while pointing to potential monomer sources, neoteric post-extraction modification and processing conditions. This lays the foundation to the following more specific chapters while illustrating the breadth of these material classes.

Dispersion of nanoparticles in optically transparent polymer matrices

Search and analysis of results of theoretical and experimental studies, materials of dissertations, literature sources and patents in the field of optical and optoelectronic instrumentation were carried out. Obtained data and recommendations on the development of methods for dispersing nanoparticles into polymer matrices for the creation of optically transparent nan composites for use in many fields of science and technology are generalized. Analysis of considered results makes it possible to conclude that for creating hybrid organic-inorganic composites with high level of dispersion of inorganic component, it is necessary to solve problems relating to compatibility of components and stabilization of filler nanoparticles in polymer matrix. Due to the limited range of hydrophilic polymers capable of forming composites with nanoparticles without stabilizers, the main approaches to the preparation of hybrid composites are using modifying additives of surfactants, as well as complex chemical reactions on the surface of inorganic filler nanoparticles. Such methods of obtaining nanocomposites with nanoparticles are laborious and involve formation of by-products and additional purification. It is shown that titanium dioxide (TiO2) and zinc oxide (ZnO) are of great interest among a large number of nanodispersed fillers of polymer matrices in preparing composite materials. There are many methods for synthesis of ZnO and TiO2 nanoparticles with various shapes and sizes, including laser ablation method, which is convenient and universal method for preparing nanosuspensions of solid-phase materials in liquid. Advantages over other methods for nanoparticle synthesis, such as the simplicity of method, environmental friendliness, low cost, and the ability to obtain cleaner colloidal solutions without using surfactants and other impurities, have made laser ablation in a liquid medium very popular among researchers.

Effect of Polymer Removal on the Morphology and Phase of the Nanoparticles in All-Inorganic Heterostructures Synthesized via Two-Step Polymer Infiltration.

Polymer templates play an essential role in the robust infiltration-based synthesis of functional multicomponent heterostructures with controlled structure, porosity, and composition. Such heterostructures are be used as hybrid organic–inorganic composites or as all-inorganic systems once the polymer templates are removed. Using iron oxide/alumina heterostructures formed by two-step infiltration of polystyrene-block-polyvinyl pyridine block copolymer with iron and aluminum precursors from the solution and vapor-phases, respectively, we show that the phase and morphology of iron oxide nanoparticles dramatically depend on the approach used to remove the polymer. We demonstrate that thermal and plasma oxidative treatments result in iron oxide nanoparticles with either solid or hollow morphologies, respectively, that lead to different magnetic properties of the resulting materials. Our study extends the boundaries of structure manipulations in multicomponent heterostructures synthesized using polymer infiltration synthesis, and hence their properties.

Hybrid composites with low reflection of IR radiation

The conditions of formation and properties of hybrid organic-inorganic composites based on epoxy polymer matrix and a mixture of magnetic and polymeric fillers are studied. Based on the study of physicochemical properties of fillers and composites, it was found that the introduction of a dispersion of magnetite modified with polymer shells and polyaniline doped with toluene sulfonic acid in the thermosetting epoxy composition in the amount of 2-6 wt.% provides the ability of composites to significant absorption and low reflection of IR and microwave range. It was found that the optimal content of the composition corresponds to the best mechanical properties of the obtained coatings, in particular, high microhardness. This makes it possible to use the proposed composition to obtain on its basis composite films and coatings for anti-radar purposes, which reduce the intensity of microwave radiation acting on the object and at the same time act as protective coatings on the surface of metals.

Information Technology in Development of Solid Polymer Electrolyte Fuel Cells

The proton-conducting hybrid organic-inorganic composites based on tetraethoxysilane and sulfonated styrene (St) and allyl glycidyl ether (AGE) copolymers, which are characterized by high exchange capacity and specific conductivity, are formed by sol-gel synthesis. The results of a quantum-chemical calculations of the geometry of the structure of an organic-inorganic composite (for a model consisting of 78 atoms) allow us to associate an increase in the proton conductivity of hybrid membranes, compared with the initial copolymer, with the generation of crystallization water and free sulfuric acid during the formation of the composite.

Hydrolytically stable luminescent Sn(II)-BTEC hybrid material: Selective sensing of chromate ions in aqueous medium

Highly efficient detection and sequestration of heavily toxic Chromate (CrO42¯) anion from the aqueous medium remains a challenging issue for the protection of public health and the ecosystem. Herein, we report a new thermally and hydrolytically stable Sn(II)-based hybrid organic-inorganic porous composite, and investigated its potential as a luminescent probe for instant and selective detection of chromate (CrO42¯) ions from the aqueous medium. The presence of chromate ions (CrO42¯) caused significant quenching (∼95 %) of the luminescence intensity of Sn(II)-BTEC. The material displayed remarkable selectivity towards CrO42¯ions in the presence of interfering metal cations and anions. The detection limit for CrO42¯ ions is calculated as low as 1.92 μM, which is significant in terms of trace amount detection from the aqueous medium. Further, the application of Sn(II)-BTEC as a chromate sensing probe in real water samples viz. tap water and lake water were examined. The synthesized Sn(II)-BTEC chemosensor displayed excellent chromate sensing capability and effectively reduced the Cr(VI) concentration within the U.S Environmental Protection Agency permissible limit of 100 μg L−1 for drinking water. Our work highlights the utility of Sn(II)-BTEC as a novel material for efficient sorption and selective luminescent sensing of chromate ions in environmentally relevant conditions.

Fabrication and evaluation of structural, thermal, mechanical and optical behavior of epoxy–TEOS/MWCNTs composites for solar cell covering

In the present study, hybrid organic–inorganic composites were fabricated from epoxy–TEOS (tetraethyl orthosilicate, Si(OC2H5)4) with various ratios (0–10 wt%) of multiwall carbon nanotubes (MWCNTs) as reinforcing nanofillers by the sol–gel method. The effect of the MWCNTs ratios on the structural, optical and mechanical characteristics and the thermal conductivity of the epoxy–TEOS/MWCNTs composites is investigated. The X-ray diffraction (XRD) analysis reveals that the pure epoxy-TEOS is amorphous, while epoxy–TEOS/MWCNTs composites are crystalline with an orthorhombic crystal structure that has an average crystallite size of 3.9 ± 0.15 nm. In addition, thermal stability and thermal conductivity were improved by adding TEOS and MWCNTs, whereas the exothermic peak temperature decreases compared with pure epoxy-TEOS. Similarly, the hardness Shore-D and tensile strength reach the optimum value at 4 wt% MWCNTs content. The significant improvement in the mechanical and thermal properties of the prepared composites could be attributed to the synergistic effect of MWCNTs and epoxy–TEOS which was emphasized by Fourier transform infrared (FTIR) spectroscopy. Moreover, epoxy-TEOS sample has high optical transmittance (T) within the visible region, but the composites samples are transparent at λ < 800 nm and have a lower value of T. The indirect optical band gap decreases from 3.59 to 2.91 eV with an increase in MWCNTs fractions from 0 to 10 wt%, respectively. However, the glass transition reflects the onset of decomposition temperatures was also considerably increased. The acquired outcomes such as a large increase in thermal conductivity and tensile stress coupled with reduced T make the composites readily applicable for a variety of applications.

Hybrid conjugated polymer/magnetic nanoparticle composite nanofibers through cooperative non-covalent interactions.

Hybrid organic–inorganic composites possessing both electronic and magnetic properties are promising materials for a wide range of applications. Controlled and ordered arrangement of the organic and inorganic components is key for synergistic cooperation toward desired functions. In this work, we report the self-assemblies of core–shell composite nanofibers from conjugated block copolymers and magnetic nanoparticles through the cooperation of orthogonal non-covalent interactions. We show that well-defined core–shell conjugated polymer nanofibers can be obtained through solvent induced self-assembly and polymer crystallization, while hydroxy and pyridine functional groups located at the shell of nanofibers can immobilize magnetic nanoparticles via hydrogen bonding and coordination interactions. These precisely arranged nanostructures possess electronic properties intrinsic to the polymers and are simultaneously responsive to external magnetic fields. We applied these composite nanofibers in organic solar cells and found that these non-covalent interactions led to controlled thin film morphologies containing uniformly dispersed nanoparticles, although high loadings of these inorganic components negatively impact device performance. Our methodology is general and can be utilized to control the spatial distribution of functionalized organic/inorganic building blocks, and the magnetic responsiveness and optoelectronic activities of these nanostructures may lead to new opportunities in energy and electronic applications.

New Proton-Conductive Membranes for Electromembrane Processes

New hybrid organic-inorganic composites based on sulfur-containing styrene copolymers and allyl glycidyl ether and tetraethoxysilane were obtained by a sol-gel synthesis method. The membranes created on the basis of composites have high proton-conductive properties and are characterized by a higher ion-exchange capacity compared with commercial membranes as Nafion and MF-4 SK. These results alloy to consider composite membranes as perspective materials for fuel cells and another electromembrane processes.

НОВЫЕ ПРОТОНПРОВОДЯЩИЕ МЕМБРАНЫ ДЛЯ ЭЛЕКТРОМЕМБРАННЫХ ПРОЦЕССОВ

New hybrid organic-inorganic composites based on sulfur-containing styrene copolymers and allyl glycidyl ether and tetraethoxysilane were obtained by a sol-gel synthesis method. The&#x0D; membranes created on the basis of composites have proton- conductive properties and are characterized by a higher heat-exchange capacity compared with commercial membranes as Nafion and MF-4&#x0D; SK, enabling to consider them as perspective membrane materials for fuel cells.

In English

A promising trend in modern material science is the development of new composite materials based on organic-inorganic systems with unique characteristics that combine the properties of individual components. Hybrid organic-inorganic composites based on the system of mono- or dimethacrylate and tetraethoxysilane (TEOS) were synthesized. The influence of the structure of the polymer matrix (2-hydroxyethyl methacrylate (HEMA) or oligoesteracrylate (MGF-9)) and the composition of relates hybrid systems on thermomechanical properties and molecular structure of the resulting composites and kinetics of polymerization till deep conversion has been studied. The synthesis of composites was carried out via the process of simultaneous polymerization of the mixtures of liquid organic and inorganic components, during which the inorganic structure is formed in situ in the polymer matrix. The kinetics of stationary photoinitiated polymerization of monomer-tetraethoxysilane systems in thin films till deep conversion was investigated by laser interferometry. The experimental integral and differential kinetic curves were obtained and kinetic parameters of photoinitiated polymerization of the studied systems were determined. As a result, the dependence of the values of the maximum rate of polymerization, conversion and time of its achievement on the ratio monomer : tetraethoxysilane in the compositions was revealed. The kinetic features of polymerization of mono- and dimethacrylates were described using the concept of microheterogeneity of the process of photoinitiated polymerization till deep conversion. The thermomechanical analysis determined the characteristic temperatures, the values of the thermomechanical structural-molecular parameters of the composites were calculated as well. It was shown that when introducing an inorganic filler into a matrix of monomethacrylate, the linear growth of the thermomechanical stability of the material can be observed depending on the quantity of TEOS, while in the case of dimethacrylate matrix this dependence can be characterized by the presence of an extremum, which is related to the formed composites. It was found that HEMA : TEOS = 95 : 5 vol. % and MGF-9 : TEOS = 90 : 10 vol. % composites have the improved thermomechanical properties. The obtained composites can be perspective for the use as a protective coating, in particular for solar collectors, and a basis for the manufacture of conductive membranes for fuel cells.

Influence of inorganic filler on properties of polymeric composites of HEMA–TEOS system

The influence of the composition of 2-hydroxyethyl methacrylate (НEMA) – tetraethoxysilane (TEOS) system on the thermal properties and structural organization of hybrid organic-inorganic composites obtained by the sol-gel method was studied. Formation of composites occurred in the process of concurrent compatible polymerization of mixtures of liquid organic and inorganic components. During the proceeding of sol-gel transformations in organic polymer medium, the inorganic structure is formed in situ in polymer matrix. Complex thermogravimetric and differential thermal analysis of the obtained composites was carried out. The thermograms of the thermal destruction of the samples were obtained, according to which the temperature intervals, the mass loss of the samples and the thermal effects of each stage were determined. The temperature-conversion parameters of thermal destruction of composites were calculated. Based on direct experimental data, taking into account the features of the destruction process, the value of the reduced temperature of composite destruction for the evaluation of their thermal stability was calculated. The dependence of the thermal stability of the material on the amount of inorganic filler in the polymer matrix has been shown. It was found that there is an optimal ratio of HEMA: TEOS, equal to 95:5 % vol., at which the composite is characterized by high thermal resistance. Such character of the inorganic phase influence on the properties of composites of the HEMA–TEOS system can be explained by the so-called “effect of small additions”. That is, with the introduction of minor amounts of the filler, its particles are distributed in a polymer matrix in micro regions with lower density – defective and weakly cross-linked zones. This leads to a decrease in the defectiveness of the polymer matrix due to the “additional ordering” of the defective zones, their compaction and, as a result, to the improving of the thermal properties of the composite. Further increase of the concentration of the inorganic phase in the system leads to a microheterogenization of the structure of the composites and deterioration of their properties. Keywords: organo-inorganic composite, sol-gel system, thermogravimetry, differential thermal analysis, thermal stability.

Sinus Augmentation with Biomimetic Nanostructured Matrix: Tomographic, Radiological, Histological and Histomorphometrical Results after 6 Months in Humans.

Background: Many bone substitutes have been applied for sinus regeneration procedures, such as autogenous bone, inorganic bovine bone, porous and resorbable hydroxyapatite, tricalcium phosphate, bioactive glass, and blood clots. The aim of the present study was a tomographic, histological and histomorphometrical evaluation in humans, of specimens retrieved from sinuses augmented with MgHA/collagen-based scaffolds, after a healing period of 6 months.Materials and Methods: Eleven healthy patients and a total of 15 sinuses were included in this study. The maxillary sinuses were filled with commercial MgHA/collagen-based scaffolds (RegenOss) with a porous three-dimensional (3D) structure (Fin-Ceramica Faenza S.p.A., Faenza, Italy). These grafts have a composite design, that replicate the organization of bone structure, obtained by a technique in which a specific hybrid organic–inorganic composite is spontaneously built by a biological mechanism. The CBCT scans were done before the procedure, after the surgical protocol (T1), and 6 months after sinus surgery (T2) for implantology. Bone specimens were stored in 10% formalin solution, embedded in a glycolmethacrylate resin and sectioned by a high-precision diamond disc. Histologic and histomorphometric analysis were carried out to evaluate the graft reabsorption and bone healing.Results: The mean volume after graft elevation, calculated for each of the 15 sinuses, was 2,906 mm3 in the immediate postoperative period (5–7 days), ranging from 2,148.8 to 3,146.4 mm3. In the late postoperative period (6 months) it was 2,806.7 mm3, ranging from 2,010.9 to 3,008.9 mm3. The sinuses were completely healed and no residual MgHA/collagen-based scaffolds were visible. Osteoblasts appeared actively secreting bone matrix and marrow spaces contained moderate numbers of stromal cells and vascular network. Osteoblasts were observed actively secreting osteoid matrix. The tissues present in the samples were composed of 1.9 ± 1.9% of lamellar bone, 36 ± 1% of woven bone and 58 ± 3.8% of marrow spaces.Conclusion: Mg-MgHA/collagen-based scaffolds can successfully be used for sinus augmentation procedures.

Application of forensic photography for the detection and mapping of Egyptian blue and madder lake in Hellenistic polychrome terracottas based on their photophysical properties

Two of the oldest synthetically produced and most widespread pigments employed in the decoration of ancient polychrome artifacts are Egyptian blue, a vitreous blue compound, and madder lake, a hybrid organic-inorganic composite. Both of these pigments are known to be photoluminescent after electronic excitation by photons in the visible and re-emission of photons in the near infrared (NIR) and visible (Vis) respectively. The emissions of Egyptian blue are typically due to d-d electronic bands and for madder lake generally due to π-π* type transitions. In this research, the photophysical properties of these two pigments were examined by means of forensic photography. The usefulness of this type of imaging is based on the properties of Egyptian blue and madder lake in exhibiting characteristic near infrared and visible emissions when excited by red and green light respectively providing reliable fingerprint markers for their identification and mapping. To probe and capture the characteristic excitation and emission photon energies of Egyptian blue and madder lake an alternate light source (ALS) and a modified digital single-lens reflex (DSLR) camera with suitable optical filters were employed in the examination and analysis of two Canosa polychrome terracotta vases from the J. Paul Getty Museum collection dated to the third century BCE. Reference materials and supplementary analysis by fiber optic reflectance spectroscopy (FORS) and X-ray fluorescence (XRF) spectroscopy were used for verification.

Interface Engineering in Hybrid Organic-Inorganic Composites for Flexible and High-Performance Thermoelectrics

Thermoelectric devices are typically rigid and their performance and reliability could be compromised by thermal stress. There is also a growing need to develop flexible thermoelectric devices for integration with wearable electronics. By using inherently soft polymers, hybrid organic/inorganic composites are considered a promising candidate for flexible thermoelectrics. In addition, the composites also provide an opportunity for enhanced thermoelectric performance by taking the advantages of low thermal conductivity and high Seebeck coefficient from the organic and inorganic components, respectively. Experimentally, however, enhanced thermoelectric performance in hybrid composites has not been observed, primarily due to inefficient carrier transport across the organic/inorganic interfaces. In particular, if the composites are energetically heterogeneous, their thermoelectric performance will be dictated by the more conductive component and there is no contribution from the less conductive component, preventing higher power factor in the composites . Here we demonstrate a strategy for interface engineering to improve the charge carrier transport from a conducting polymer, i.e., poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which has an electrical conductivity greater than 1000 S/cm [1-3], to nanostructures of a prototypical inorganic thermoelectric material, i.e., Bi0.5Sb1.5Te3 (BST), which is the state-of-the-art thermoelectric materials at room temperature (with thermoelectric figure of merit ZT~1) [4]. PEDOT:PSS consists of hydrophobic PEDOT in core and hydrophilic PSS in shell, where PSS is an insulator but it is required to dope EDOT as an oxidizing agent during the polymerization process of EDOT. Therefore, conduction in PEDOT:PSS is mediated by phonon-assisted hopping that requires an activation energy due to the delocalized carriers within the backbones of PEDOT. The key to enhance this hopping process in a BST-PEDOT composite is to reduce the hopping distance for transport of PEDOT-to-PEDOT and PEDOT-to-BST. This could be achieved in a uniform dispersion of BST nanostructures in PEDOT, in which the discrepancy in the activation energy is minimized. To demonstrate this concept, we fabricated BST particles by using a spark erosion method, which involves repetitive spark discharges to produce fine powders [5], and then mixed the particles in PEDOT:PSS (CLEVIOS PH1000) using a non-ionic surfactant and controlling its micelle concentration (concentration ranging from 0.5 wt % to 10 wt%). We then characterized thermoelectric properties and morphologies of the hybrid films fabricated under various conditions. We demonstrated homogeneous dispersion of BST in the PEDOT matrix and consequently efficient interfacial charge transport by optimizing the surfactant. Our results show that hybrid BST/polymer composites are promising for flexible and high-performance thermoelectrics. The strategy developed in this work may also be applicable to other heterogeneous energy conversion architectures consisting of organic and inorganic materials.

Platinum-supported mesoporous silica of facile recovery as a catalyst for hydrogenation of polyaromatic hydrocarbons under ultra-mild conditions

Here we describe a new platinum catalyst comprised of Pt(0) nanoparticles immobilized on a modified magnetic mesoporous silica support modified with electron donor groups (–N). The material is constituted of controlled pore size (2.4–4.1 nm) and serves as a template for the generation of Pt nanoparticles (2–4 nm). The catalytic activity of the supported Pt nanoparticles was investigated in the catalytic reduction of anthracene under ultra-mild conditions. A complete morphological characterization of the hybrid organic–inorganic composite which confirms the formation of the hybrid material is also given. The catalyst was easily recycled using a small magnet, and it could be reused at least twice without significant loss of its catalytic activity. ICP–OES reveals that after the recyclability study no leaching of Pt or Si could be detected in the products (<0.01 ppm) which confirms the chemical stability of the material allowing it to be used as a potential hydrogenation catalyst for solid–liquid reactions with facile catalyst recovery.

The Synthesis and Properties of Copolymers Based on N-Vinylpyrazole

Copolymers of N-vinylpyrazole with vinyl chloride and methyl methacrylate were produced by radical polymerisation. The involvement of the obtained (co) polymers in sol–gel synthesis with the participation of tetraethoxysilane leads to the production of hybrid organic–inorganic composites. Films were obtained from solutions of the (co)polymers and composites by casting, and their proton conductivity was determined (7.8 103 S cm1).