Search results for "Alate"
showing 10 items of 695 documents
Elasticity and long-term behavior of recycled polyethylene terephthalate (rPET)/montmorillonite (MMT) composites
2014
Abstract Recycled polyethylene terephthalate (rPET) nanocomposites with various amounts of montmorillonite clay (MMT) have been manufactured by using twin screw extrusion. By rising MMT weight content Wf up to 1 wt.% it is possible to increase yield strength and ultimate strength of the composite by 17% and 27% respectively in comparison to neat rPET. Introduction of MMT in the rPET leads also to considerable increase of the modulus of elasticity E. Relationship E(Wf), however, is non-linear and is characterized by slow-down in E growth along with increasing MMT content. At low nanofiller content experimental results are sufficiently well described by using the method of Mori–Tanaka and the…
Smart High-κ Nanodielectrics Using Solid Supported Polyoxometalate-Rich Nanostructures
2011
Utilizing Langmuir-Blodgett deposition and scanning probe microscopy, we have investigated the extent to which cations alter the self-assembly processes of hybrid polyoxometalates (POMs) on surfaces. The well-defined 2D hexagonal nanostructures obtained were extensively characterized and their properties were studied, and this has revealed fascinating dielectric behavior and reversible capacitive properties. The nanostructures are extremely stable under ambient conditions, and yet exhibit fascinating self-patterning upon heating. These findings present POMs as effective smart nanodielectrics and open up a new field for future POM applications. (c) 2011 American Chemical Society.
Electrochemically-induced TiO2 incorporation for enhancing corrosion and tribocorrosion resistance of PEO coating on 7075 Al alloy
2018
Abstract 7075 Al alloy was PEO-treated in a silicate based electrolyte containing 3 g l-1 potassium titanyl oxalate using unipolar and bipolar pulsed current waveforms. The coating formed by the bipolar waveform with the wider cathodic pulses showed volcano-like surface morphology with no evidence of large pores at the metal/coating interface. It revealed the highest corrosion performance due to the synergistic effect of TiO2 incorporation and structural/morphological features along with a better passivation behavior indicating no pitting susceptibility. For this coating, the tribocorrosion tests showed no potential drop during sliding under 1 N with the lowest volume loss of 0.022 mm3.
Heteropolyacid-Based Heterogeneous Photocatalysts for Environmental Application
2015
Polyoxometalates (POMs) are a wide class of discrete nanosized transition metal–oxygen clusters. The synthesis of POMs has received great interest not only because they present intriguing architectures but also because they have potential applications in catalysis, medicine, electrochemistry, materials design or models for self-assembling nanoscale systems. Recently, POMs have also been studied as green and cheap photocatalysts. The potentialities of POMs are attributed to their unique structural features; indeed, POMs are photostable and non-toxic, have oxygen-rich surfaces and excellent redox properties and possess photochemical characteristics similar to those of the semiconductor photoc…
The solidification behavior of a PBT/PET blend over a wide range of cooling rate
2009
In recent years, much attention has been paid to the development of high-performance polyester blends, among which blends of polybutylene terephthalate/polyethylene terephthalate (PBT/PET) are expected to exhibit remarkable properties as far as their crystallization behavior is concerned. Through trial and error, appropriate commercial compositions have been chosen which could not be otherwise explained by a suitable interpretation of the mechanisms determining their solidification behavior. The solidification behavior of a 60/40 w/w PBT/PET blend was studied in a wide range of cooling conditions, according to a continuous cooling transformation (CCT) procedure developed previously, aiming …
Influence of small amounts of polyvinylchloride on the recycling of polyethyleneterephthalate
1999
Abstract Polyethylene terephthalate (PET), and polyvinyl chloride (PVC), are commonly encountered in plastics stream coming from separate collections of plastic bottles. The presence of PVC in the recycled PET is very dangerous because of the chain scission provoked by the hydrogen chloride evolved from the macromolecules during degradation of PVC. Recycled PET must be free of PVC; contents of PVC as little as 100 ppm can induce degradation and discoloration of the polyester. PET, in its turn, is degraded when the processing is carried out in the presence of water. In previous work, however, the degradation of PET was eliminated and rather an increase of the molecular weight has been measur…
Recycling of a Biodegradable Polymer Blend
2020
Mechanical recycling is one of the possible ways to enhance the value of postconsumer plastic materials. However, the final performance of the recycled material will strongly depend on the quality of the selection made on the recycled product and on the degradation of the properties. In this context, the present study examines the effect of reprocessing for five successive extrusion cycles on the rheological, mechanical and thermal properties of a poly(butylene adipate-co-terephthalate) (PBAT)-based blend on samples reprocessed in both dry and wet conditions. The results showed that when the sample was processed after drying, degradation of the material was less than when it was processed i…
Redesign of the Geometry of Parts Produced from PBT Composite to Improve Their Operational Behavior
2021
Parts produced from PBT-GF30 (70% polybutylene terephthalate +30% fiberglass) are very often used in car construction, due to the properties of this material. The current trend is to make parts with a shape designed to be as complex as possible, to take over many functions in operation. During the research, a part that is a component of the structure of car safety systems, and that must be completely reliable in operation, was analyzed. This piece has a complex shape that involves the intersection of several walls. Thus, the research aimed at establishing the optimal radius of connection between the walls (R), the ratio between the thickness of the intersecting walls (K) and the angle of in…
Electrochemical Characterization of Polyelectrolyte/Gold Nanoparticle Multilayers Self-Assembled on Gold Electrodes
2006
Polyelectrolyte/gold nanoparticle multilayers composed of poly(l-lysine) (pLys) and mercaptosuccinic acid (MSA) stabilized gold nanoparticles (Au NPs) were built up using the electrostatic layer-by-layer self-assembly technique upon a gold electrode modified with a first layer of MSA. The assemblies were characterized using UV-vis absorption spectroscopy, cyclic and square-wave voltammetry, electrochemical impedance spectroscopy, and atomic force microscopy. Charge transport through the multilayer was studied experimentally as well as theoretically by using two different redox pairs [Fe(CN)(6)](3-/4-) and [Ru(NH(3))(6)](3+/2+). This paper reports a large sensitivity to the charge of the out…
Robustness and electrical reliability of AZO/Ag/AZO thin film after bending stress
2017
Abstract The increasing interest in thin flexible and bendable devices has led to a strong demand for mechanically robust and electrically reliable transparent electrodes. Indium doped Tin Oxide (ITO) and Aluminium doped Zinc Oxide (AZO) are among the most employed transparent conductive oxides (TCO) and their reliability on flexible substrates have thus received a great attention. However, a high flexibility is usually achieved at very low thickness, which, unfortunately, compromises the electrical conductivity. Here we report the effects of mechanical bending cycles on the electrical and optical properties of ultra thin AZO/Ag/AZO multilayers (45 nm/10 nm/45 nm) and, for comparison, of AZ…