Solid State Phenomena Vols. 99-100

Abstract: The paper presents the results of studies of the hydrogen sorption properties of nanocrystalline Mg2Ni intermetallic prepared by mechanical (ball) milling under controlled shearing/impact mode. The pre-alloyed intermetallic powders were subjected to ball milling under various controlled milling conditions such as shearing, high-energy shearing and impact in a magnetic Uni-Ball-Mill 5. The hydriding properties were evaluated by monitoring the absorption PC isotherms by the conventional constant-volume method using Sieverts semi-automatic apparatus. Changes of structure during processing and hydriding properties of nanostructured Mg2Ni intermetallic powders are shown and discussed.

Abstract: Birefringence induced by the orientation of polymer main chains during injectionmoulding or extrusion processing restricts the application of optical polymers to optical devices that require the polarization state of incident light to be maintained. To compensate this birefringence of polymers we propose using the “birefringent crystal dopant method” - homogeneous doping with an opposite birefringent needle-like crystal. Strontium carbonate (SrCO3) was selected for this purpose and synthesized, with a length of about 200nm and a width of about 20nm. SrCO3 was doped into poly(MMA/BzMA= 78/22(wt./wt.)) film. The film was uniaxially drawn at 130°C and 4mm/min. For the first time, the positive birefringence of the drawn copolymer film at a wavelength of 633nm was compensated by doping with 0.3wt.% of SrCO3 without loss of transparency and thermostability.

Abstract: The behaviour of the luminescence spectra of the organic dye R6G in a multiple scattering polymer matrix was studied with reference to the parameters of the scattering media. It was found that some of the luminescent parameters depend on the concentration of scattering particles, the refractive index of the scattering particles and the sample thickness. As it was shown, that the reason for these dependences is the reabsorption of luminescence light enhanced by multiple light scattering. In addition, an increase in the absorption caused by multiple scattering was observed.

Abstract: The paper presents the results of research into the dielectric characteristics of modified Kapton and Upilex polyimides with C60 – fullerene contents of 0.1-2.0 % wt. The influence of temperature and frequency on the time constants of b-relaxation of modified polyimides is shown.

Abstract: A novel approach to load a hydrophilic bovine serum albumin (BSA) into the drug carriers was proposed in terms of thermosensitive dual-shell structures which were fabricated with poly(N-isopropylacrylamide), poly(lactide) and Au nanoparticles. Spherically well-defined dualshell structures were constructed by a modified-double-emulsion method (MDEM). The lower critical solubility temperature of the structures was shifted to 36.4 °C which was confirmed by UVVis spectroscopy.

Abstract: The influence of mixtures of Ni0.5Zn0.4Cu0.1Fe2O4, CoFe2O4, and graphite on the permeability, permittivity and microwave absorption properties in a composite embedded with insulating polymeric matrix, that can be used for X- and P-band radar absorption, has been investigated. Thermodynamic modelling of the complex ferrite system has been demonstrated by the controlled simultaneous coprecipitation of all ions inolved in the composite in the selected working pH ranges. The method employed is very convenient for the synthesis of multicomponent systems with a homogenous distribution of compositions.

Abstract: Special features of the formation and growth of polymer films, formed on steel under the effect of glow discharge in heptane were studied by means of atomic force microscopy, X-ray photoelectron spectroscopy and contact wetting angle. At low film thickness a thin sticky layer is formed, from which macromolecular cone-shaped formations protrude. With an increase in film thickness the sticky layer disappears and the number of cone-shaped formations increase and they eventually coalesce. As the surface coverage with cones increases the films become thicker and stronger. The cones are assumed to be the film growth sites, which arise during the relaxation of the film’s internal stresses. In addition these growth sites can form under the effect of the stresses from extended defects in the substrate.

Abstract: The influence of plasma processing of silica and crystalline silicon substrates on the formation of polymeric layers of PS/PMMA blends by sorption from 50 vol. % concentration toluene solutions was analyzed. The morphology dependence of PS/ PMMA blend films on the type and condition of substrate processing was studied by X-ray photoelectron spectroscopy (XPS), ellipsometry and atomic force microscopy (AFM). It was shown that reduction of carbon and oxygen components from the surface contaminants as well as the existence of a nonstoichiometric SiOx layer on the Si surface contributed to the hydrophilicity of the substrate. These processes can be used to produce thin nanostructured polymer blend films.