1.

Phase evolution and microwave dielectric properties of MgO-B[sub]2O[sub]3-SiO[sub]2-based glass-ceramics

In this article we report about the sintering, crystallization and dielectric characterization of MgO-B2O3-SiO2 -based glass-ceramics. Addition of TiO2 nucleating agent enhanced crystallization and consequently increased permittivity and Qxf-values.

COBISS.SI-ID: 25008679

2.

Observing the nucleation phase of atomic layer deposition In situ

We present in situ topographical observationsof film growth during the initial cycles of atomic layer deposition (ALD) using scanning tunneling microscopy (STM). We present cycle-by-cycle STM topographs of zinc sulfide films during ALD on Au(111) surfaces, tracking individual grains, 5 nm in diameter, as they grow over tens of cycles. We find that grain morphology is temperature dependent and grain size increases with deposition temperature from 100 to 160 °C.

COBISS.SI-ID: 26220839

3.

Dielectric properties of the bismuth neodymium titanate pyrochlore solid solution

The dielectric properties of a new, cubic, pyrochlore-type solidsolution Bi(1.6-1.08x)NdxTi2O(6.4-0.11x) have been studied across the compositional range 0.35 ( x ( 0.86. The dielectric constant (e) of the ceramics based on the pyrochlore-type solid solution within the experimental compositional range varied from 104 to 76 at 1 MHz, whereas the dielectric losses were well below tan  = 8 10-3 The temperature coefficient of the dielectric constant τk for single-phase pyrochlore samples was found to be in the range between - 20 and -40 ppm/K. Below room temperature dielectric relaxation phenomena were observed for all the compositions.

COBISS.SI-ID: 25792295

4.

Effect of a TiO[sub]2 nucleating agent on the nucleation and crystallization behavior of MgO-B[sub]2O[sub]3-SiO[sub]2 glass

In this article we report about the influence of TiO2 nucleating agent on the nucleation and crystallization processes in the MgO-B2O3-SiO2 (MBS) glass. It was found that TiO2 in concentrations 1-15% did not change the morphology of Mg2B2O5 crystallites, however it influenced the nucleation rate and crystallization mechanism. In the pure MBS glass the crystallization was 3-dimensional bulk with diffusion controlled crystal growth rate. The increase of nucleation rate was observed at TiO2 content )3 %, while the change from diffusion to interface-controlled growth rate occurred at 5 wt. % of TiO2.

COBISS.SI-ID: 25763879

5.

Poly(D,L-lactide-co-glycolide)/hydroxyapatite core-shell nanosphere

The surface properties of PLGA/HAp core–shell nanoparticles loaded with clindamycin obtained by an ultrasonic processing method and their changes under the simulated physiological conditions during the degradation process (when the morphology is changed starting from the nanospheres, over micrometer-sized plate-like films to a porous network) were investigated. The dynamic change of the surface properties of this material obtained in a water environment showed an increase of the surface area (up to 70 m2/g) and an improved wettability (estimated water contact angle was in the range between 40◦ and 60◦) suggesting the possibility for its good interaction with cells. The in vitro tests are in a good correlation with this hypothesis, showing a high level of cytocompatibility of the material with the mouse L929 and human lung MRC-5 fibroblasts. The fibroblasts were able to achieve the contactwith the material’s surface and to attach onto it. The significance of HAp, as the bioceramic phase within the PLGA/HAp core–shell nanoparticles, may be brought into relationship with its role in improving the surface properties of PLGA/HAp obtained during the degradation process. These properties are closely related to the bioactivity and biocompatibility of this material, which are highly relevant for its biomedical application.

COBISS.SI-ID: 25612071