Search results for "character"

Characterization of oriented protein-ceramic and protein-polymer-composites for cartilage tissue engineering using synchrotron μ-CT

2007

Abstract In this paper we report on the synthesis of three different gelatine based scaffold materials for the reconstruction of articular cartilage defects. The first scaffold design is based on an unmodified, oriented gelatine network, while the second design further comprises an attached inorganic hydroxyapatite layer and the third design includes poly(l-lactide) microspheres as a model material for future drug-release applications. All three scaffold designs were characterized and imaged using synchrotron μ-CT, obtaining a complete volumetric reconstruction of a previously defined sample region. Furthermore, two unmodified scaffolds were cultivated for one week with porcine chondrocytes…

On the reaction of [Ph2(OH)Si]2O with t-Bu2SnCl2: Synthesis and characterization of the first well defined polystannasiloxane [(t-Bu2SnO)(Ph2SiO)2]n

1997

Abstract The high yield synthesis of [(t-Bu2SnO)(Ph2SiO)2], 1 is reported. Compound 1 is a linear polymer in the solid state but a six-membered ring in solution.

Mesoporous Materials Incorporating Metal Triflates

2016

Metal triflates attracted a large interest as catalysts in the past three decades especially due to the Lewis acid properties exhibited by these compounds and the variety of the functional group transformations. This chapter proposes an overview presenting the catalytic performances of triflates both as molecular compounds and as triflates dispersed in different solid matrices. In the first part the performances of molecular triflates in organic reactions carried out in the presence of water or water as solvent considering both water-sensitive and -insensitive metals are discussed. Then, the importance of materials incorporating triflates is demonstrated for catalysts obtained via immobiliz…

Synthesis and Characterization of a Soluble Bimetallic Oxalate-Based Bidimensional Magnet:  [K(18-crown-6)]3[Mn3(H2O)4{Cr(ox)3}3]

2006

The "templating" K crown ether cation allows for the preparation of soluble layered oxalate-based bimetallic magnets, as in [K(18-crown-6]3{Mn3(H2O)4[Cr(ox)3]3}, with an unprecedented bidimensional polymeric anionic network that involves both oxalato bridges and H bonds. As in other 2D oxalate-bridged compounds, the compound behaves as a soft ferromagnet, with the onset of magnetic ordering occurring at 3.3 K.

Shear flow characterization of blends containing liquid crystal polymers

1992

A simple phenomenological approach is proposed in order to predict the presence of minima in the viscosity-composition curves of blends of thermoplastic with liquid crystal polymer (LCP). When the viscosity of the liquid crystal polymer is larger than that of the thermoplastic matrix, a minimum is observed. A possible explanation of the presence of yield stress in the flow curves of these blends is also given.

Characterization of ultra-high-molecular-weight polyethylene (UHMWPE) modified by ion implantation

2004

Abstract Surface modification of ultra high molecular weight polyethylene (UHMWPE) is induced by ion implantation of different ions at 300 keV energy. The aim of this work was the chemical, physical and mechanical characterization of the modified material in order to know deep inside about the effect of the ion beam upon the polymer. The irradiated surfaces are investigated by Raman spectroscopy, infrared absorption and micro-hardness analysis, scanning electron microscopy. Pin on disc measurements valuated the wear of the UHMWPE against a stainless steel probe; wear resistance increases of about 76% after the ion implantation. This result can be attributed to the ion bombardment inducing a…

FTIR TENTATIVE CHARACTERIZATION OF HUMIC ACIDS EXTRACTED FROM ORGANIC MATERIALS

2001

Turkish humic acids, extracted from different materials, were characterized by their infrared spectra and by means of acidity measurements. The information obtained is of great interest to ascertain the nature and origin of humic acid samples.

Metallic Conductivity in a Polyoxovanadate Radical Salt of Bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF): Synthesis, Structure, and Physical Chara…

2004

Characterization of Interaction Between Humic Acids and Buckminsterfullerene Using Flourescene Spectroscopy

2017

The interaction between buckminsterfullerene C60 and humic acids (HA) of different origins was compared using fluorescence spectroscopy as a function of pH, humic acid concentration, ionic strength. Binding constants between fullerene and humic acids were calculated. It can be suggested that the complexation was driven by hydrophobic interactions depending on the properties of the interacting compounds. Hydrophobic interaction model as indicated by linear Stern-Volmer plots and high Kd values is characterizing the interaction between buckminsterfullerene C60 and humic acids The results of this study support the development of an understanding of the fate of nanomaterials in the environment …

1991