Water-Soluble Nanocomposites Containing Co3O4 Nanoparticles Incorporated in Poly-1-vinyl-1,2,4-triazole.

New water-soluble nanocomposites with cobalt oxide nanoparticles (Co3O4NPs) in a poly(1-vinyl-1,2,4-triazole) (PVT) matrix have been synthesized. The PVT used as a stabilizing polymer matrix was obtained by radical polymerization of 1-vinyl-1,2,4-triazole (VT). The polymer nanocomposites with Co3O4 nanoparticles were characterized by ultraviolet-visible, Fourier-transform infrared spectroscopy, atomic absorption spectroscopy, transmission electron microscopy, dynamic light scattering, gel permeation chromatography, and simultaneous thermogravimetric analysis. The resulting polymer nanocomposites consist of spherical isolated cobalt nanoparticles with a diameter of 1 to 13 nm. The average hydrodynamic diameters of macromolecular coils are 15-112 nm. The cobalt content in nanocomposites ranges from 1.5 to 11.0 wt.%. The thermal stability of nanocomposites is up to 320 °C.

Synthesis and DC Electrical Conductivity of Nanocomposites Based on Poly(1-vinyl-1,2,4-triazole) and Thermoelectric Tellurium Nanoparticles.

In this work, the structural characteristics and DC electrical conductivity of firstly synthesized organic-inorganic nanocomposites of thermoelectric Te0 nanoparticles (1.4, 2.8, 4.3 wt%) and poly(1-vinyl-1,2,4-triazole) (PVT) were analyzed. The composites were characterized by high-resolution transmission electron microscopy, X-ray diffractometry, UV-Vis spectroscopy, and dynamic light scattering analysis. The study results showed that the nanocomposite nanoparticles distributed in the polymer matrix had a shape close to spherical and an average size of 4-18 nm. The average size of the nanoparticles was determined using the Brus model relation. The optical band gap applied in the model was determined on the basis of UV-Vis data by the Tauc method and the 10% absorption method. The values obtained varied between 2.9 and 5.1 nm. These values are in good agreement with the values of the nanoparticle size, which are typical for their fractions presented in the nanocomposite. The characteristic sizes of the nanoparticles in the fractions obtained from the Pesika size distribution data were 4.6, 4.9, and 5.0 nm for the nanocomposites with percentages of 1.4, 2.8, and 4.3%, respectively. The DC electrical conductivity of the nanocomposites was measured by a two-probe method in the temperature range of 25-80 °C. It was found that the formation of an inorganic nanophase in the PVT polymer as well as an increase in the average size of nanoparticles led to an increase in the DC conductivity over the entire temperature range. The results revealed that the DC electrical conductivity of nanocomposites with a Tellurium content of 2.8, 4.3 wt% at 80 °C becomes higher than the conventional boundary of 10-10 S/cm separating dielectrics and semiconductors.

Composite Hydrogels Based on Bacterial Cellulose and Poly-1-vinyl-1,2,4-triazole/Phosphoric Acid: Supramolecular Structure as Studied by Small Angle Scattering.

New composite hydrogels (CH) based on bacterial cellulose (BC) and poly-1-vinyl-1,2,4-triazole (PVT) doped with orthophosphoric acid (oPA), presenting interpenetrating polymeric networks (IPN), have been synthesized. The mesoscopic study of the supramolecular structure (SMS) of both native cellulose, produced by the strain Komagataeibacter rhaeticus, and the CH based on BC and containing PVT/oPA complex were carried out in a wide range of momentum transfer using ultra- and classical small-angle neutron scattering techniques. The two SMS hierarchical levels were revealed from 1.6 nm to 2.5 µm for the objects under investigation. In addition, it was shown that the native BC had a correlation peak on the small-angle scattering curves at 0.00124 Å-1, with the correlation length ξ being equal to ca. 510 nm. This motive was also retained in the IPN. The data obtained allowed the estimation of the fractal dimensions and ranges of self-similarity and gave new information about the BC mesostructure and its CH. Furthermore, we revealed them to be in coincidence with Brown's BC model, which was earlier supported by Fink's results.

Strong Antimicrobial Activity of Highly Stable Nanocomposite Containing AgNPs Based on Water-Soluble Triazole-Sulfonate Copolymer.

A new hydrophilic polymeric nanocomposite containing AgNPs was synthesized by chemical reduction of metal ions in an aqueous medium in the presence of the copolymer. A new water-soluble copolymer of 1-vinyl-1,2,4-triazole and vinylsulfonic acid sodium salt (poly(VT-co-Na-VSA)) was obtained by free-radical copolymerization and was used as a stabilizing precursor agent. The structural, dimensional, and morphological properties of the nanocomposite were studied by UV-Vis, FTIR, X-ray diffraction, atomic absorption, transmission and scanning electron microscopy, dynamic and electrophoretic light scattering, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. Hydrodynamic diameter of macroclubs for the copolymer was 171 nm, and for the nanocomposite it was 694 nm. Zeta potential for the copolymer was -63.8 mV, and for the nanocomposite it was -70.4 mV. The nanocomposite had strong antimicrobial activity towards Gram-negative and Gram-positive microorganisms: MIC and MBC values were in the range of 0.25-4.0 and 0.5-8.0 µg/mL, respectively.

Evaluation of the Safety and Toxicity of the Original Copper Nanocomposite Based on Poly-N-vinylimidazole.

A new original copper nanocomposite based on poly-N-vinylimidazole was synthesized and characterized by a complex of modern physicochemical and biological methods. The low cytotoxicity of the copper nanocomposite in relation to the cultured hepatocyte cells was found. The possibility to involve the copper from the nanocomposite in the functioning of the copper-dependent enzyme systems was evaluated during the incubation of the hepatocyte culture with this nanocomposite introduced to the nutrient medium. The synthesized new water-soluble copper-containing nanocomposite is promising for biotechnological and biomedical research as a new non-toxic hydrophilic preparation that is allowed to regulate the work of key enzymes involved in energy metabolism and antioxidant protection as well as potentially serving as an additional source of copper.

Green Synthesis of Stable Nanocomposites Containing Copper Nanoparticles Incorporated in Poly-N-vinylimidazole.

New stable nanocomposites with copper nanoparticles (CuNPs) in a polymer matrix have been synthesized by green chemistry. Non-toxic poly-N-vinylimidazole was used as a stabilizing polymer matrix and ascorbic acid was used as a reducing agent. The polymer CuNPs nanocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic absorption spectroscopy (AAS), and thermogravimetric analysis (TGA). It was shown, using the dynamic light scattering (DLS) method, that the hydrodynamic diameters of nanocomposites depend on the CuNPs content and are in an associated state in an aqueous medium. The copper content in nanocomposites ranges from 1.8 to 12.3% wt. The obtained polymer nanocomposites consist of isolated copper nanoparticles with a diameter of 2 to 20 nm with a spherical shape.

NonToxic Silver/Poly-1-Vinyl-1,2,4-Triazole Nanocomposite Materials with Antibacterial Activity.

Novel silver/poly-1-vinyl-1,2,4-triazole nanocomposite materials-possessing antimicrobial activity against Gram-positive and Gram-negative bacteria-have been synthesized and characterized in the solid state and aqueous solution by complex of modern physical-chemical and biologic methods. TEM-monitoring has revealed the main stages of microbial cell (E. coli) destruction by novel nanocomposite. The concept of direct polarized destruction of microbes by nanosilver proposed by the authors allows the relationship between physicochemical and antimicrobial properties of novel nanocomposites. At the same time, it was shown that the nanocomposite was nontoxic to the fibroblast cell culture. Thus, the synthesized nanocomposite combining antibacterial activity against Gram-positive and Gram-negative bacteria as well as the absence of toxic effects on mammalian cells is a promising material for the development of catheters, coatings for medical devices.

Green synthesis of water-soluble nontoxic polymeric nanocomposites containing silver nanoparticles.

New water-soluble nontoxic nanocomposites of nanosized silver particles in a polymer matrix were synthesized by a green chemistry method. Nontoxic poly(1-vinyl-1,2,4-triazole) was used as a stabilizing precursor agent in aqueous medium. Glucose and dimethyl sulfoxide were used as the silver ion-reducing agents to yield silver nanoparticles 2-26 nm and 2-8 nm in size, respectively. The nanocomposites were characterized by transmission electron microscopy, ultraviolet-visible and Fourier transform infrared spectroscopy, X-ray diffraction, atomic absorption, and thermogravimetric data analysis. The nanocomposites showed strong antimicrobial activity against Gram-negative and Gram-positive bacteria.