Vol 12, No 3-4 (2017)

An electrolytic method for the synthesis of metal complex aggregates from polymethine dyes on the surface of anodes from metals capable of electrolytic oxidation has been developed. It has been concluded that the electrochemical method for the synthesis of aggregates from polymethine dyes has technological prospects for the creation of photosensitive elements in organic nanoelectronics and photonics.

Using the methods of powder X-ray diffraction, transmission electron microscopy, and EXAFS spectroscopy, the phase behavior of bimetallic Pt–Cu nanoparticles with different architecture that are deposited on a highly disperse carbon carrier has been investigated during their thermal treatment in inert atmosphere. It is established that Pt–Cu nanoparticles with a Cu-core–Pt-shell structure rearrange into nanoparticles with a Pt–Cu solid-solution structure in the temperature range from 280 to 300°C. This transformation is accompanied by a sharp change in the unit-cell parameter. Such a change in the crystal lattice parameter does not occur during the thermal treatment of material with similar composition containing Pt–Cu nanoparticles with a solid-solution structure. The results can be used in elucidating the structure of Pt–M/C materials with different nanoparticle architectures.

Studies devoted to the development of ceramic membranes, which are capable of separating gaseous mixtures, first and foremost of H₂–CH₄, are presented in this paper. The membranes from alumina prepared on the basis of thermochemical activation (TCA) products of gibbsite contain a considerable amount of macropores and possess low selectivity in gas separation. In order to reduce the contribution of macropores to the porous structure of membranes, we have introduced glass additives, which sinter more easily than alumina. Tests of the samples, in which a part of TCA product is replaced by glass, have shown that the factor of separation for gaseous mixtures of H₂–CH₄ increases to 2.2. In the next part of this work, we synthesize the ceramic membranes, which were modified by carbon nanotubes (CNTs) with an external diameter of 3–5 nm. It is shown that when CNTs are introduced into the composition of a ceramic membrane, the selectivity in the separation of gaseous mixtures of H₂–CH₄ increases to 2.4.

A method for preparing a nanocomposite material containing gold nanorods on a polyurethane foam matrix, which is of interest in analytical chemistry, has been developed by the sorption modification of the matrix. It is found that the sorption of gold nanorods on polyurethane foam was achieved after 30 min of phase contact in the presence of 0.4 M NaCl as an electrolyte. The dependence of the sorption on time is described by the pseudo–first order kinetic equation with a rate constant of 0.17 min^–1. The sorption isotherm is fitted by the Langmuir equation. Calculated in the framework of this model, values of the sorption constant and the sorption capacity are equal to 77.6 × 10³ L/mol of Au and 15 mg/g, respectively. The potential possibility of the resulting nanocomposite material application for determining reducing agents by diffuse reflectance spectrometry is demonstrated.

A method for the microwave synthesis of multifunctional magnetic nanomaterials with a “core–multilayered shell” structure is proposed. The optimal conditions for the step-by-step synthesis of a material on the basis of magnetite Fe₃O₄ (“core”) modified by silicon-containing polymers (ТEOS + MPTMS), gold nanoparticles, and immobilized antineoplastic drug doxorubicine (DOX) (“shell”) are found. Using instrumental techniques, the composition of the prepared nanomaterials (Fe₃O₄@TEOS/MPTMS@Au_coll@DOX) is investigated and the sizes of particles synthesized at different temperatures and reagent ratios are determined. The sorption processes involving DOX and synthesized nanomaterials are studied at different phase contact times, doxorubicine concentration, and рН of the medium. The possibility of controlled release of DOX from the nanoparticle surface upon changing the рН value is demonstrated. The synthesized hybrid nanoparticles could be promising for different biomedical applications, in particular, for targeted drug delivery and local hyperthermia.

Biocompatible and biodegradable polymer microparticles are contemporary medicines able to eliminate the side effects and unsatisfactory pharmacokinetics of already existing preparations. In this work we have developed a high-tech scalable method for the synthesis of paclitaxel-loaded poly(3-hydroxybutyrate) (PHB)-based microparticles. These particles were synthesized on a B-90 Buchi nano spray dryer by piezoelectric spray drying in an inert atmosphere. A regular spherical shape, narrow size distribution, and satisfactory results for the release of paclitaxel from the polymeric matric of microparticles in vitro make this polymeric medicinal form promising for its further application in pharmaceutics. Nanoparticles with a similar composition synthesized via the laboratory one-stage emulsification method were used for comparison. This study is the first stage in the creation of a sustained-action anticancer paclitaxel preparation.