Carbon plastics based on thermoplastic polyimide binders modified with nanoparticles

© 2016, Pleiades Publishing, Ltd.Polyimides (PIs) crystallized from melts are promising thermally stable, heat-resistant plastics with high destruction viscosities. Nanocomposites that in turn serve as matrixes for carbon plastics can be obtained on the basis of PIs filled with carbon nanoparticles of various structures and morphologies. The presence of the composite-in-composite structure gives rise to the enhancement of dissipation properties of the polymer matrix in particular and to an increase in the crack resistance of the carbon plastic in general

Development of sers substrates based on nanoparticles obtained by pulsed laser ablation

SERS spectroscopy is an effective method for the determination of organic and biological compounds, which finds its place in many areas of human life: the analysis of works of art and food 24 YOUNG SCIENTISTS SESSION SESSION Y products, the identification of drugs and drugs, the study of biological structures, incl. at the cellular level. The creation of simple and effective SERS substrates is an urgent task in the development of this method. This paper presents the results of a study of SERS substrates based on gold nanoparticles (NPs). Gold NPs were obtained by pulsed laser ablation of an Au metal target in alcohol using a Nd:YAG laser (1064 nm, 7 ns, 150 mJ). The resulting colloidal solution was applied onto glass substrates by the drop method, varying the number of layers. The SERS characteristics were studied using a model dye rhodamine 6G using Renishaw inVia Basis Raman microscope. The samples were excited in the region of surface plasmon resonance of gold by laser radiation of 532 nm. The results of the study showed that with an increase in the number of deposited layers up to 5, the intensity of the Raman scattering of the dye increases linearly. With a further increase in the number of layers, the signal saturates. This data correlates with SEM data. At the beginning, an increase in the packing density of NPs in the plane of the substrate is observed. Accordingly, the number of "hot spots" increases, which contribute to the amplification of the signal. Further, the homogeneity of the NP layer deteriorates, and large bulk agglomerates appear. Thus, we have developed a simple method for obtaining SERS substrates, which made it possible to increase the signal intensity up to three orders of magnitude

Interface features and electronic structure of Bi2SiO5/β-Bi2O3 hetero-junction

Atomic and electronic structure of Bi2SiO5/β-Bi2O3 hetero-junction was described by means of density functional theory. The interface was found to be narrow-gap semiconductor with indirect band gap. The redistribution of states near the Fermi level in hybrid structure and the impact of spin-orbit coupling are discussed

Structure and optical properties of nanocrystalline titanium dioxide prepared via pulsed laser ablation in liquid

Crystal structure and optical properties of titaniu

Physical origins of double peak phase matching in GaSe

Double peak phase matching was recorded during experimental study of parametric frequency converters based on GaSe, its solid solutions crystals like GaSe1-xSx and ZnGeP2. Its physical origins are identified as presence of twin, large difference between cut and PM angles, self-heating effect at appropriate conditions, mismatched second (Φ) phase matching angle and microdefects. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Synthesis of cubic ferrite CoFe2O4 by spray pyrolysis

The phase composition, morphology, and structural parameters of cobalt ferrospinel powders synthesized by spray pyrolysis combined with drop sol-gel combustion are determined. The obtained data are compared with those of the powders synthesized by sol-gel combustion

Ag-Pd nanoparticles prepared by laser ablation for selective oxidation of propylene glycol to lactic acid

Silver/palladium composite nanoparticles (NPs) obtained by pulsed laser ablation in liquid (PLAL) technique catalyze oxidation of propylene glycol (PG) to lactic acid (LA) in alkaline media. The PLAL technique allows obtaining silver/palladium NPs with different silver/palladium molar ratio. Addition of palladium increases PG conversion (up to 52%) and LA selectivity (up to 88%). The reaction temperature and silver/palladium molar ratio strongly affects the catalytic activity of the silver/palladium composite NPs

Visualization of nanoconstructions with DNA-Aptamers for targeted molecules binding on the surface of screen-printed electrodes

Nanoconstructions of gold nanoparticles (NPs) obtained via pulsed laser ablation in liquid with DNA-aptamer specific to protein tumor marker were visualized on the surface of screen-printed electrode using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). AuNPs/aptamer nanoconstuctions distribution on the solid surface was studied. More uniform coverage of the carbon electrode surface with the nanoconstuctions was showed in comparison with DNA-aptamer alone on the golden electrode surface. Targeted binding of the tumor marker molecules with the AuNPs/DNA-aptamer nanoconstuctions was approved