Search results for "COMPOSITE"

CORRELATION BETWEEN THE CHEMICAL-PHYSICAL PROPERTIES OF CNT AND MACROSCOPIC PROPERTIES OF RELATED NANOCOMPOSITES: A STATISTICAL APPROACH

2014

In the frame of this work, two different samples of CNTs, namely CNT 1 and CNT 2, were synthesized [1] with different degree of purity and aspect ratio and used as fillers either without any treatment or after a plasma-oxidation, to prepare polycarbonate (PC)-based nanocomposites by melt mixing. The influence of plasma treatment, filler content and type of CNTs on the mechanical, dynamic-mechanical, and electrical properties of the materials was assessed by a two level full factorial design. The morphological analysis carried out by SEM and TEM evidenced the formation of a nanohybrid structure when oxidized CNTs were used as filler. Generally speaking, CNT 2 showed the best dispersion and t…

Plasma Modification of MWCNTs and Their Use in the Preparation of PA6/MWCNT Nanocomposites

2011

INVESTIGATION OF THE INDENTATION BEHAVIOUR OF FOAM CORED LIGHTWEIGHT COMPOSITE SANDWICHES

2011

Hyaluronic Acid–Silica Nanohybrid Gels

2013

Excessive water sorption and low mechanical properties are a severe drawback in some biomedical applications of hyaluronic acid (HA). A way to improve these properties is here explored through the novel concept of nanohybrid hydrogels consisting of a HA matrix including different amounts of silica-derived species. This inorganic filler phase controls the mechanical and swelling properties of HA cross-linked matrices. Below a 2 wt % of silica in the systems, nanoparticle aggregates of tens of nanometers and silica oligomers are distributed more or less homogeneously throughout the organic matrix, without percolating. This morphology of the silica phase is accompanied by an increased swelling…

Reliability of numerical models for simulating galvanic corrosion processes

2012

International audience; Maturity of numerical simulation represents an important issue in the development of predictive models of galvanic corrosion. As widely used in electrochemical engineering, a coupled electrochemical-transport-reaction (CETR) model is recommended to simulate the current distribution above a galvanic corrosion cell made of the cut-edge of a galvanized steel sheet. Nevertheless, simulating current density distributions obtained experimentally by scanning vibrating electrode technique (SVET) above such a galvanic cell appears to be more accurate using an electrostatic model considering a homogeneous conductivity. In this case, the absence of concentration gradients next …

Reactivity of gypsum faces according to the relative humidity by scanning force microscopy

1997

Abstract This article reports the experimental observation of the stability of the different faces of calcium sulphate dihydrate (gypsum CaSO 4 .2H 2 O) according to the relative humidity. Scanning Force Microscopy experiments were carried out with a view to discerning the topography of the surfaces, the chemical compositional domains, and in an attempt to evaluate the friction and viscoelastic properties of the surface. Our results indicate that the (010) face of gypsum is hydrophilic and very reactive contrary to the less hydrophilic (120) and (101) faces which remain stable depending on the relative humidity. It is clear from our results that a precipitation like process can be induced b…

Flexible minerals: self-assembled calcite spicules with extreme bending strength.

2013

Flexi-Fibers Glass or metal fibers can show incredible flexibility. Natalio et al. (p. 1298 ; see the Perspective by Sethmann ) used the protein silicatein-α, which is responsible for the biomineralization of silicates in sponges, to guide the formation of spicules made of calcite. These synthetic spicules could be bent to a high degree because of their inherent elasticity, whilst retaining the ability to guide light.

Rheological and Mechanical Behavior of LDPE/Calcium Carbonate Nanocomposites and Microcomposites

2012

The increase of the interest in polymer nanocomposites has been leading to continuous growing search toward nanofillers alternative to the widely known clay-based ones. One of these possible alternatives is represented by calcium carbonate nanoparticles, which have not been widely investigated in such context. In this article, a study on the rheological and morphological behavior of dif- ferent low density polyethylene-calcium carbonate nanocomposites, compared with a reference calcium carbonate microcomposite, is presented. Several different nanosized calcium carbonates at different amounts were used. The results from the rheological and me- chanical tests outlined that only minor changes …

Stable amorphous calcium oxalate: synthesis and potential intermediate in biomineralization.

2014

Amorphous calcium oxalate nanoparticles with sizes of 10–30 nm were synthesized at room temperature by the hydrolysis of a dimethyl oxalate from ethanol solution.

Microstructure, mechanical characteristics and cell compatibility of β-tricalcium phosphate reinforced with biodegradable Fe–Mg metal phase

2015

The use of beta-tricalcium phosphate (β-TCP) ceramic as a bioresorbable bone substitute is limited to non-load-bearing sites by the material׳s brittleness and low bending strength. In the present work, new biocompatible β-TCP-based composites with improved mechanical properties were developed via reinforcing the ceramic matrix with 30 vol% of a biodegradable iron-magnesium metallic phase. β-TCP-15Fe15Mg and β-TCP-24Fe6Mg (vol%) composites were fabricated using a combination of high energy attrition milling, cold sintering/high pressure consolidation of powders at room temperature and annealing at 400 °C. The materials synthesized had a hierarchical nanocomposite structure with a nanocrystal…