Towards controlling the morphology of cobalt loaded nanocomposites in polyol process with polyethylene glycol

The polyol process is one of the simple, efficient and productive methods for the synthesis of metal loaded polymer composites. Functional properties of metal-polymer nanocomposites are determined by chemical composition, size and morphology of their particles. Finding effective ways to control the nanoparticle's properties during the polyol process is a crucial task. The effect of molar ratio Mn+/OHPEG on the formation of cobalt loaded metal-polymer nanocomposites during a one-pot two-component polyol process by polyethylene glycol with Mr = 4000 g·mol–1 (PEG) was studied. The PEG-based polyol process and the formation of cobalt nanophase were studied at molar ratios νCo2+/νOH(PEG) = 1:1, 1:10, 1:100 and 1:500 using UV-Vis, diffuse reflectance IR and ATR FT-IR spectroscopy, nanoparticle tracking analysis (NTA), dynamic light scattering (DLS). It was found that PEG can act as a reducing agent and stabilizing matrix for the cobalt nanophase at a ratio higher than Mn+/OHPEG= 1:10. The composition and morphology of Co/PEG nanocomposites were determined by XRD and TEM methods. Two types of spheroid particles with average diameters of 88±55 nm / 8±4 nm and 12±3 nm / 3±1 nm, respectively, represent Co/PEG nanocomposites 1:500 and 1:100. Scaly structures with a diameter of 15±5 nm are formed at a molar ratio of νCo2+/νOH(PEG) = 1:10. An increase in the Co2+ content in the PEG-based polyol process leads to the immobilized cobalt nanophase Co3O4 (1:500), Co0/CoO (1:100), CoO (1:10) in PEG. Co/PEG nanocomposites are hemocompatible. The HC50value depends on the composition and morphology of the nanoparticles

Hyperbranched Polyester Polyfumaratomaleate Doped with Gd(III) and Dy(III) Ions: Synthesis, Structure and Properties

For the first time, metal–polymer complexes have been synthesized using hyperbranched polyester polyfumaratomaleate as a matrix, the structure of which has been established by 1H NMR, IR, electron spectroscopy, and elemental analysis methods. The formation of complexes with Gd(III) and Dy(III) ions involving fumarate and maleate groups of the polyester was proved by IR and electron spectroscopy methods. It was established that the structure of the coordination units has the form of a square antiprism. The compositions and conditional logarithms of the stability constants of the complexes were determined. It was established that complexation with lanthanide ions promotes emission enhancement in the ligand

TESTING DIFFERENT METHODS OF ARTIFICIAL VESICLES INDUCTION FROM T CELLS

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Effect of the Synthetic Approach on the Formation and Magnetic Properties of Iron-Based Nanophase in Branched Polyester Polyol Matrix

This article shows the success of using the chemical reduction method, the polyol thermolytic process, the sonochemistry method, and the hybrid sonochemistry/polyol process method to design iron-based magnetically active composite nanomaterials in a hyperbranched polyester polyol matrix. Four samples were obtained and characterized by transmission and scanning electron microscopy, infrared spectroscopy and thermogravimetry. In all cases, the hyperbranched polymer is an excellent stabilizer of the iron and iron oxides nanophase. In addition, during the thermolytic process and hybrid method, the branched polyol exhibits the properties of a good reducing agent. The use of various approaches to the synthesis of iron nanoparticles in a branched polyester polyol matrix makes it possible to control the composition, geometry, dispersity, and size of the iron-based nanophase and to create new promising materials with colloidal stability, low hemolytic activity, and good magnetic properties. The NMR relaxation method proved the possibility of using the obtained composites as tomographic probes

Hybrid Nanostructures of Hyperbranched Polyester Loaded with Gd(III) and Dy(III) Ions

Hyperbranched polymers are successful nanoscale functional platforms for loading metal ions and creating promising nanomaterials for medicine. This work presents the synthesis of metal–polymer nanostructures based on a second generation hyperbranched polyester with eight terminal benzoylthiocarbamate (BTC) groups loaded with Gd(III) or Dy(III) ions. Their structure (Fourier transform infrared spectroscopy) and morphology (transmission electron microscopy), photophysical (ultraviolet–visible and luminescence spectroscopy), thermophysical, magnetic activity, relaxivity, and aggregation properties (nanoparticle tracking analysis) were studied. The formation of the metal–polymer complex is carried out by chelation of lanthanide ions −CO and −CS groups of the BTC fragment of polyester. Coordination units with composition Ln(III)-3BTC (Ln = Dy, Gd) were localized on the branched polymer platform. The load is three lanthanide ions per branched polyester polybenzoylthiocarbamate macromolecule. Logarithms of stability constants of complexes and composition of coordination polyhedron have been determined. The dysprosium complex is in a paramagnetic state with antiferromagnetic correlations, and the gadolinium complex is in a paramagnetic state. The relaxivity of the Dy(III) and Gd(III) complexes increased by 2.5 and 3 times, respectively, compared to their nitrates. An important achievement is the identification of rare-earth metal (REM)-controlled morphology and self-organization for Dy(III) and Gd(III) complexes with branched polyester polybenzoylthiocarbamate in solution and on the surface. Spherical nanostructures for the dysprosium complex and nanorods for the gadolinium complex were observed. Synthesized REM-loaded nanostructures with polyester polybenzoylthiocarbamates have low hemotoxicity and can be applied in biomedicine

Impedimetric Aptasensor for Ochratoxin A Determination Based on Au Nanoparticles Stabilized with Hyper-Branched Polymer

An impedimetric aptasensor for ochratoxin A (OTA) detection has been developed on the base of a gold electrode covered with a new modifier consisting of electropolymerized Neutral Red and a mixture of Au nanoparticles suspended in the dendrimeric polymer Botlorn H30®. Thiolated aptamer specific to OTA was covalently attached to Au nanoparticles via Au-S bonding. The interaction of the aptamer with OTA induced the conformational switch of the aptamer from linear to guanine quadruplex form followed by consolidation of the surface layer and an increase of the charge transfer resistance. The aptasensor makes it possible to detect from 0.1 to 100 nM of OTA (limit of detection: 0.02 nM) in the presence of at least 50 fold excess of ochratoxin B. The applicability of the aptasensor for real sample assay was confirmed by testing spiked beer samples. The recovery of 2 nM OTA was found to be 70% for light beer and 78% for dark beer