National Institute Of Materials Physics - Romania

Publications

860 articles found

571. Hybrid dextran-iron oxide thin films deposited by laser techniques for biomedical applications

Authors: Predoi, D; Ciobanu, CS; Radu, M; Costache, M; Dinischiotu, A; Popescu, C; Axente, E; Mihailescu, IN; Gyorgy, E

Published: MAR 1 2012, MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS, 32, 302, DOI: 10.1016/j.msec.2011.10.032

Iron oxide oxide nanoparticles were prepared by chemical co-precipitation method. The nanoparticles were mixed with dextran in distilled water. The obtained solutions were frozen in liquid nitrogen and used as targets during matrix assisted pulsed laser evaporation for the growth of hybrid, iron oxide nanoparticles-dextran thin films. Fourier Transform Infrared Spectroscopy and X-ray diffraction investigations revealed that the obtained films preserve the structure and composition of the initial, non-irradiated iron oxide-dextran composite material. The biocompatibility of the iron oxide-dextran thin films was demonstrated by 3-(4.5 dimethylthiazol-2yl)-2.5-diphenyltetrazolium bromide-based colorimetric assay, using human liver hepatocellular carcinoma cells. (C) 2011 Elsevier B.V. All rights reserved.

572. Optical and electrical properties of arylenevinylene compounds thin films prepared by vacuum evaporation

Authors: Rasoga, O; Vacareanu, L; Grigoras, M; Enculescu, M; Socol, M; Stanculescu, F; Ionita, I; Stanculescu, A

Published: JAN 2012, SYNTHETIC METALS, 161, 2617, DOI: 10.1016/j.synthmet.2011.10.001

This paper discusses the properties of two arylenevinylene oligomers thin films deposited by vacuum evaporation on different substrates. The morphology of the thin films was investigated by scanning electron microscopy and atomic force microscopy, and the optical properties by UV-Vis and fluorescence spectroscopy. The optical nonlinear phenomenon of two-photon absorption induced fluorescence has been evidenced in the thin films of these compounds. We have also investigated the electrical properties of semiconductor/insulator/semiconductor (ITO/oligomer/Si) heterostructures in correlation with the contact energetic barriers, morphological and structural properties of the layers. (C) 2011 Elsevier B.V. All rights reserved.

573. TILT c AXIS CRYSTALLITE GROWTH OF ALUMINIUM NITRIDE FILMS BY REACTIVE RF-MAGNETRON SPUTTERING

Authors: Stan, GE; Pasuk, I; Trinca, LM; Galca, AC; Enculescu, M; Miculescu, F

Published: JAN-MAR 2012, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 7, 50, DOI:

The article reports on the tilted growth of textured aluminium nitride thin films obtained by radio-frequency magnetron sputtering onto 50 mm diameter Si (111) wafers, in reactive atmosphere, in a planar sputtering system without tilting the substrate and with no additional sputtering geometry alterations. The films were investigated using, X-ray diffraction, spectroscopic ellipsometry and scanning electronic microscopy, done by local measurements on the wafer surface, at different distances from the centre. A progressive increase of the tilt angle when moving away from the sample centre has been found. The maximum tilt angle of the columnar AlN crystallites, obtained near the edges of the wafer, is about 7 degrees. The results showed also that tilting is associated with smaller thickness and larger dispersion of the c axis orientation. Synthesizing inclined c axis AlN films should allow the fabrication of surface acoustic wave devices based on shear waves for liquid sensor applications.

574. COMPARATIVE SURVEY OF THE MOST USED SELF ADHESIVE DENTAL CEMENTS BASED ON RESIN COMPOSITES

Authors: Gatin, E; Matei, E; Pirvu, D; Galbinasu, B; Iordache, S

Published: JAN-MAR 2012, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 7, 214, DOI:

The present study is dedicated to the investigation of self-adhesive cements, based on resin composites (RBC). Reported cases of dental restorations decays, are influenced by interface/surface quality and marginal adaptation to dentin and enamel. The influence is given by organic and inorganic (filler) phase as well. Regarding the organic phase, this is involved in bonding with dentin remains and enamel. Differences were noticed between the investigated materials; results from EDX patterns reveal major differences between inorganic phase (filler) in specimens and a non homogenous state for all samples. Results are confirmed by the mapping patterns. Low discontinuity areas for samples specimen were remarked for Biscem and RelyXU100 samples, then for MaxcemElite dental cement. Regarding mechanical properties, those are dramatically influenced by the filler. The major determination is given by the particles size and state of homogeneity for a given specimens composition. SEM results revealed a textured structure with a small filler particles size for RelyX U100 than other samples (less than, d - 1 mu m). A stirring method is recommended for all samples before application for an improved homogeneity.

575. ZnO Thin Films Deposited on Textile Material Substrates for Biomedical Applications ZnO Thin Films Deposited on Textiles

Authors: Duta, L; Popescu, AC; Dorcioman, G; Mihailescu, IN; Stan, GE; Zgura, I; Enculescu, I; Dumitrescu, I

Published: 2012, TECHNOLOGICAL INNOVATIONS IN SENSING AND DETECTION OF CHEMICAL, BIOLOGICAL, RADIOLOGICAL, NUCLEAR THREATS AND ECOLOGICAL TERRORISM, 210, DOI: 10.1007/978-94-007-2488-4_20

We report on the coating with ZnO adherent thin films of cotton woven fabrics by Pulsed laser deposition technique in order to obtain innovative textile materials, presenting protective effects against UV radiations and antifungal action.

576. COMBINATORIAL PULSED LASER DEPOSITION OF AG-CONTAINING CALCIUM PHOSPHATE COATINGS

Authors: Socol, G; Socol, M; Sima, L; Petrescu, S; Enculescu, M; Sima, F; Miroiu, M; Popescu-Pelin, G; Stefan, N; Cristescu, R; Mihailescu, CN; Stanculescu, A; Sutan, C; Mihailescu, IN

Published: APR-JUN 2012, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 7, 576, DOI:

Embedding silver (Ag) into CaPs one could expect the enhancement of the antimicrobial performances of coatings for load bearing implants. The aim of this research was to evaluate whether the cellular morphology is influenced by the variation of Ag content, as well as by the solubility and morphological features of Ag-containing CaP coatings obtained by combinatorial pulsed laser deposition technique. In this view, we developed compositional libraries of either Ag and hydroxyapatite (HA) or Ag and beta-tricalcium phosphate (beta-TCP). The Ag content along the length of the combinatorial CaP coatings increased up to a maximum of similar to 1 at.%. SEM and AFM images evidenced the abundant presence of particulates typical for CaP coatings deposited by PLD. AFM histograms showed that the samples were rough with RMS values within 61-209 nm range. Ag content values up to 0.6 at. % into HA coatings were found nontoxic for mesenchymal stem cell (MSC) growth.

577. HIGH-DENSITY GREEN PHOTONS EFFECTS ON NaCl SOLUTIONS DETECTED BY RED BLOOD CELLS MEMBRANES

Authors: Mitrica, R; Popescu, I; Paslaru, L; Badila, D; Polosan, S; Cristache, L; Ionescu, E; Tataru, C; Comorosan, S

Published: JAN-MAR 2012, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 7, 235, DOI:

This paper presents a new technique for investigating the modifications induced by high-density green light [GL] on water in NaCl solutions. Solutions of 0,45 g% and 0,9 g%, irradiated with green light (lambda = 527 nm, intensity 3.10(5) Lx) were used. As a receptor for measuring the irradiation effect we used red blood cell (RBC) permeability in hypotonic media, the so-called osmotic shock. After RBC lysis in hypotonic medium, the released hemoglobin was spectrophotometrically determined at lambda = 550 nm. The values of the osmotic shock for the samples obtained with GL-irradiated NaCl solutions were significantly lower than the values obtained with non-irradiated controls. This may indicate that the penetration of water inside the membranes canaliculi is hindered. This new type of result was complemented by chronoamperometry and impedance spectroscopy determinations. The current density of the irradiated solution decreases from the value of 29.5 mu A.cm(-2) in the control to 17.74 mu A.cm(-2) in the irradiated sample with a corresponding decrease of ionic mobility. The impedance value of the GL irradiated NaCl solutions were significantly lower than the control values, thus correlating well with the data recorded by chronoamperometry. All these data may indicate large water cluster formation through GL irradiation which are beyond the cellular aquaporine channels capacity. A similar process is identified by using red light, as well as blue light, though with a much smaller output.

578. PHYTOSYNTHESIS OF GOLD NANOPARTICLES USING CAESALPINIA PULCHERRIMA (PEACOCK FLOWER) FLOWER EXTRACT AND EVALUATION OF THEIR ANTIMICROBIAL ACTIVITIES

Authors: Nagaraj, B; Divya, TK; Barasa, M; Krishnamurthy, NB; Dinesh, R; Negrila, CC; Predoi, D

Published: JUL-SEP 2012, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 7, 905, DOI:

Caesalpinia pulcherrima (Linn) popularly known as Peacock flower in India belongs to family Caesalpiniace. In this work, we describe environment friendly technique for green synthesis of gold nanoparticles from AuCl4 solution using the Caesalpinia pulcherrima (Peacock flower) flower extract as reducing agent. The gold nanoparticles were characterized using UV-visible spectroscopy and transmission electron microscopy (TEM). The UV-visible spectra indicate a strong Plasmon resonance that is located at similar to 450 nm. The TEM analysis shows that products have spherical morphology with size ranging between 10-50 nm. The study also indicates that gold nanoparticles show good antimicrobial activities when compared to the standard antibiotics.

579. SYNTHESIS OF PLANT MEDIATED GOLD NANOPARTICLES USING FLOWER EXTRACTS OF CARTHAMUS TINCTORIUS L. (SAFFLOWER) AND EVALUATION OF THEIR BIOLOGICAL ACTIVITIES

Authors: Nagaraj, B; Malakar, B; Divya, TK; Krishnamurthy, NB; Liny, P; Dinesh, R; Iconaru, SL; Ciobanu, CS

Published: JUL-SEP 2012, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 7, 1296, DOI:

The ecofriendly synthesis of nanoparticles through various biological sources helps in exploring various herbs. Generally, nanoparticles are prepared by a variety of chemical methods which are not environmentally friendly. In this report we use aqueous extracts of Carthamus Tinctorius L. (Safflower) flowers for the synthesis of gold (Au) nanoparticles. A rapid and convenient method was considered for the synthesis of gold nanoparticles by reduction with auric chloride. UV-visible spectroscopy studies were carried out to assess the formation of Au nanoparticles. Transmission electron microscopy (TEM) was used to characterize the Au nanoparticles. TEM image divulges that nano triangle and spherical shaped gold nanoparticles are formed with polydispersed size, and the sizes are in the range of 40 nm to 200 nm. The antimicrobial activity of gold nanoparticles was performed on various gram negative bacteria and fungus. The gold nanoparticles showed more inhibitory activity on pathogenic gram negative bacteria than fungus.

580. BIOCOMPATIBLE MAGNETIC IRON OXIDE NANOPARTICLES DOPED DEXTRAN THIN FILMS PRODUCED BY SPIN COATING DEPOSITION SOLUTION

Authors: Iconaru, SL; Andronescu, E; Ciobanu, CS; Prodan, AM; Le Coustumer, P; Predoi, D

Published: JAN-MAR 2012, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 7, 409, DOI:

Magnetic iron oxide nanoparticles (MION) doped dextran thin films for biomedical applications have been deposited onto the glass substrate by spin coating method. To understand the influence of the MION doping dextran on physico-chemical properties was conducted. The particle concentration in the samples defined as the oxide/dextran mass ratio, R was 1 and 5. MION -dextran thin films were charcacterized by various techniques such as X-ray Photoelectron Spectroscopy (XPS), Glow Discharge Optical Emission Spectroscopy (GDOES), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Attachment (EDAX). These techniques have allowed the structural elucidation of polysaccharides thin films. The second derivative FT-IR spectra showed clearly that the polysaccharides bands. The biocompatibility of the maghemite-dextran thin films was demonstrated using MTT test, with the aid of hFOB 1.19 osteoblats cells. To evaluate cell proliferation rate quantitative by the hFOB 1.19 cells on HAp samples were cultured to 4 days. Cellular morphology was investigated using FESEM to obtain qualitative information of osteoblast cells on MION-dextran thin films. The data stronlgy suggest the potential use of iron oxide-dextran nanocomposite as a poetinal marker for or biomedical applications.