Search results for "Composite"

Halloysite-Based Bionanocomposites

2017

Scientific research has been invigorated by a new class of biodegradable materials as alternatives to polymers derived from fossils. Such biomaterials can also offer economic advantages because they are derived from renewable resources. Several biopolymers (gelatin, chitin, chitosan, starch, pectin, cellulose and its modified versions, etc.) have been exploited to produce films and formulations. Their use is limited because of fast degradation, predominant hydrophilic character, and, in some cases, unsatisfactory mechanical properties. However, the properties of these polymers can be improved by using inorganic fillers such as additives. Halloysite nanotube is a promising green filler for t…

Colloidal stability of halloysite clay nanotubes

2019

Abstract The colloidal stability of halloysite clay nanotubes dispersion is reviewed showing the strategy and the mechanism to obtain stable systems in water and apolar solvents. The selective modification of halloysite inner/outer surfaces can be achieved by exploiting electrostatic interactions. The adsorption of anionic surfactants onto the halloysite cavity allows generating inorganic cylindrical micelles that can be separated from the solvent. On the other hand, the functionalization of halloysite shell by positively charged surfactants drives to obtain stable water-in-oil emulsions. The interactions with ionic and nonionic polymers alters the dispersability of halloysite due to electr…

Effects of halloysite content on the thermo-mechanical performances of composite bioplastics

2020

Abstract The aim of this study is the design and preparation of Mater-Bi/halloysite nanocomposite materials that could be employed as bioplastics alternative to the petroleum derived products. The biocomposite materials at variable halloysite content (from 0 to 30 wt%) were prepared by using the solvent casting method. We investigated the mechanical behaviour and the thermal properties of the prepared nanocomposites in order to estimate their suitability as biocompatible packaging materials. The thermo-mechanical characteristics were correlated to the nanocomposites' morphologies, which were studied by Scanning Electron Microscopy (SEM). As a general result, the physico-chemical performance…

Assembly of a planar, tricyclic B4N8 framework with s-indacene structure.

2007

A neutral, formally 16pi-electron, tricyclic tetrahydrazidotetraborane was obtained in a two-step procedure involving self-assembly of a dilithiodiborate with B(4)N(8) framework and subsequent oxidation of the phenylborate moieties to boranes and biphenyl using Fe(II) as an oxidant.

EFFECT OF DRAWING ON THE STRUCTURE AND THE DYNAMIC-MECHANICAL BEHAVIOR OF SALTED POLYCAPROAMIDE.

1982

Abstract Structural determinations, obtained through density, birefringence, and WAXS measurements, are reported for nylon 6/inorganic salt fiber samples as a function of draw ratio. They confirm the possibility of achieving very high amorphous orientation in these systems. Dynamic-mechanical data have also been collected which allow determination of glass transition temperatures. These are also discussed in terms of structural parameters.

1992

Semi-IPN's of different composition, based on linear poly(methyl vinyl ether) (PVME) and crosslinked polystyrene are studied using stress and birefringence measurements in simple elongation. From quasistatic stress-strain experiments at constant T(experiment)-Tg, it can be deduced that the stress results only from the deformation of the polystyrene network, while the PVME chains do not contribute to the macroscopic stress. The concentration dependence of the network modulus is adequately described by the rubber elastic theories

Almond by-products: Extraction and characterization of phenolic compounds and evaluation of their potential use in composite dough with wheat flour

2018

Blanched skins and blanching water, by-products of almond processing, were evaluated as potential ingredients of bakery products. The research included three phases: i) optimization of skin drying; ii) optimization of quali-quantitative determination of phenolic compounds, by comparing three extracting protocols; iii) assessment of the impact of by-products on the rheology of composite meals with wheat flour. Besides being less time-consuming, drying at 60 °C for 30 min lowered effectively skin moisture (7.86 g/100 g) and kept better odor notes (leafy and rancid odor scored 6.1 and 0.2, respectively), as well as higher content of phenolics (813.89 µg/g, with the most effective extracting me…

Anti-oxidative effects and harmlessness of asymmetric Au@Fe3O4 Janus particles on human blood cells

2014

AbstractThe physical properties of asymmetric Janus particles are highly promising for future biomedical applications. However, only a few data is available on their biological impact on human cells. We investigated the biological impact of different Au@Fe3O4 Janus particle formulations in vitro to analyse specific uptake modalities and their potential cytotoxic effects on human cells of the blood regarding intravenous injection. We demonstrate that Au@Fe3O4 Janus particles exhibit a similar or even better biocompatibility compared to the well-studied spherical iron oxide nanoparticles. The impact of Janus particles on cells depends mainly on three factors. (1) Surface functionalization: NH…

Enhancement of SOD activity in boehmite supported nanoreceptors

2018

The binuclear Cu2+ complex of a pyridinophane polyamine ligand ranking amongst the fastest SOD mimetics so far reported displays a remarkable SOD activity enhancement when grafted to the surface of boehmite (γ-AlO(OH)) nanoparticles (BNPs).

Grafted squaramide monoamine nanoparticles as simple systems for sulfate recognition in pure water.

2012

New simple systems formed by a chain containing a squaramide function and a quaternised amine group attached to boehmite or silica-coated boehmite nanoparticles are able to discriminate anions in pure water.