V. N. Filippov

Toward high-throughput monitoring of metallodrug–protein interaction using capillary electrophoresis in chemically modified capillaries

The performance of capillary electrophoresis (CE) operating with a sulfonated capillary for the separation of protein adducts of anticancer ruthenium(III)-based drugs was evaluated. The coated capillary was shown to yield improved resolution of albumin- and transferrin-bound species of ruthenium compared with that attained with the bare fused-silica capillary. The coating also showed an increased reproducibility of migration times and peak areas and allowed reasonably high efficiency separation of analytes (up to 1300 theoretical plates per meter), which display high affinity toward a fused-silica surface. In addition, due to rather high electroosmotic flow (EOF, > 45 x 10(-5)cm(2)V(-1)s(-1)) in the coated capillary, it enabled fast counter-EOF monitoring of albumin and transferrin adducts. This benefit, together with requiring only a short flush with the background electrolyte to have migration times reproducible (at < 1.5% relative standard deviation), makes this wall-modified capillary holding promise for CE examination of fast reactions such as those accompanying protein-drug interactions and biotransformations associated with drug delivery via protein binding.

Corundum/lanthanum hexaaluminate/alumina nanofiber ceramic composite

We describe a corundum-matrix ceramic composite loaded with layered lanthanum hexaaluminate microparticles and reinforced with alumina nanofibers. The components of the composite are prepared by sol-gel processing. Scanning electron microscopy results indicate that the microparticles and nanofibers are uniformly distributed over the matrix. Surface-modified alumina nanofibers are shown to have the best effect on the strength of the matrix.

Microphase separation in a cross-linked epoxy phenol polymer

The microphase separation on the surface of samples of a cross-liked epoxy phenol (EP) polymer produced by the curing of a composition containing an epoxy diane oligomer (EO) and a phenol formaldehyde oligomer (PO) has been investigated using electron microscopy with decoration by silver chloride. It has been shown that, in the cross-liked EP polymer, there is a quasi-lattice of mixed-type AgCl nanoparticles, which consists of two sublattices. The formation of simple lattices of particles is caused by the microphase separation according to the type of nucleation and growth of fractal clusters of the cross-liked EO; the spinodal decomposition in the binary system; and the formation of interpenetrating polymer networks represented by the superposition of two lattices of particles or two infinite phase clusters (cross-liked EO and PO, respectively).

The Effect of Yttrium Oxide on the Microstructure and Properties of Ceramics Based on Lanthanum Hexaaluminate Synthesized by the Sol–Gel Method

The effect of a sintering aid, yttrium oxide, on the properties of ceramic materials based on lanthanum hexaaluminate synthesized by a sol–gel method is studied. The synthesis of a sol of ternary oxide composition conducted via hydrolysis of a mixed salt solution leads to the formation of particles with a “nucleus – shell”-type structure. The synthesis of lanthanum hexaaluminate with the participation of these particles proceeds at 1000 – 1100°C, and the sintering of ceramic at 1400 – 1500°C. Ceramic based on yttrium-containing lanthanum hexaaluminate exhibits improved strength properties.

Microstructure of zirconium oxide ceramic fibers obtained by template synthesis

Ceramic fibers of zirconium oxide partially stabilized by ceric oxide were obtained by the template synthesis using sols of initial metals oxides. The formation of the microstructure of ceramic fibers has been studied by the methods of thermal analysis, differential scanning calorimetry, X-ray analysis, scanning electron microscopy, and X-ray spectral analysis. Features of formation of a microstructure of fibers depending on conditions of their preparation were revealed.

Ceramic composite [78ZrO2–21CeO2–Y2O3]/La0.85Y0.15Al11O18/Al2O3. Microstructure and properties

A ceramic composite [78ZrO2–21CeO2–Y2O3]/La0.85Y0.15Al11O18/Al2O3 (zirconium dioxide submicroparticles stabilized by cerium and yttrium oxides), which consists of a matrix filled with layered submicroparticles of lanthanum hexaaluminate modified by yttrium oxide and reinforced by Al2O3 nanofibers, was obtained. Components of the composite were synthesized by the sol-gel method, except for Al2O3 nanofibers obtained by the electric explosion method. The microstructure and properties of the composite depend on the composition and methods of its formation and sintering. The composite is intended to be used as a construction material.

Ceramic Composition Material for Operation under Extreme Conditions

A ceramic material based on a corundum matrix formed by submicrocrystalline particles of aluminum oxide and filled with microsized particles of lanthanum hexaaluminate is obtained. The matrix is reinforced additionally by aluminum oxide nanofibers, and the fiber surface is modified by zirconium dioxide nanoparticles. All the components of the ceramic composite are synthesized by the sol-gel method. The composite has high strength and thermal properties. The coefficient of friction and abradability of the composite material make it possible to recommend its application for operation under dry friction conditions at high temperatures and in frictional units of fine mechanical instruments.