Search results for "composites"

Preparation and Characterization of PLA-Hydrotalcite Nanocomposites

2011

Nanocompositi a base polimerica e molecole POSS: comportamento reologico e proprietà fisiche

2012

Nanocomposites based on PS, PE, or ethylene-acrylic acid (ESCOR 5001) and POSS (Polyhedral oligomeric SilseSquioxanes) molecules were prepared by melt mixing. The nanocomposites’s structure-property relationships were analyzed mainly by rheological investigations and the variations with respect to the matrices were highlighted. The results of the rheological analysis show that the POSS molecules affect the properties in the molten state and act as plasticizer that is contrasted by the hydrogen bonds. The inorganic cage’s structure and the organic nature of the vertex groups of the molecules POSS play an important role in modulating the dispersion and in determining the final properties of t…

Gold nanoparticle catalysis of the cis-trans isomerization of azobenzene

2013

Ablated, “pseudo-naked” gold nanoparticles (AuNPs) catalyze the cis–trans isomerization of substituted azobenzenes. para-Substitution was found to affect the rate of isomerization, suggesting the participation of AuNP-mediated electron transfer in the isomerization mechanism. Fil: Hallet Tapley, Geniece. University of Ottawa; Canadá Fil: D'Alfonso, Claudio. University of Ottawa; Canadá. Universita Di Roma; Italia Fil: Pacioni, Natalia Lorena. University of Ottawa; Canadá Fil: McTiernan, Cristopher D.. University of Ottawa; Canadá Fil: Gonzalez Bejar, Maria. University of Ottawa; Canadá. Universidad de Valencia; España Fil: Lanzalunga, Osvaldo. Universita Di Roma; Italia Fil: Alarcon, Emilio…

Physicochemical characterization of octakis(alkyloxy)-substituted Zn(ii)-phthalocyanines non-covalently incorporated into an organogel and their rema…

2007

A series of octakis(alkyloxy)-substituted Zn(II)-phthalocyanines were efficiently incorporated into an organogel made of (1R,2R)-trans-1,2-bis(dodecanoylamino)cyclohexane by means of multiple cooperative non-covalent interactions, and SEM revealed the formation of unique brush-like nanostructures.

Nanostructured medical sutures with antibacterial properties

2014

Bacterial repellence in suture materials is a desirable property that can potentially improve the healing process by preventing infection. We describe a method for generating nanostructures at the surface of commercial sutures of different composition, and their potential for preventing biofilm formation. We show how bacteria attachment is altered in the presence of nanosized topographies and identify optimum designs for preventing it without compromising biocompatibility and applicability in terms of nanostructure robustness or tissue friction. These studies open new possibilities for flexible and cost-effective realization of topography-based antibacterial coatings for absorbable biomedic…

Controlling dielectrical properties of polymer blends through defined PEDOT nanostructures

2016

[EN] The paper reports the crucial role of the morphology of poly(3,4-ethylenedioxythiophene) (PEDOT) nanostructures on the thermal and dielectric properties of polymer blends prepared thereof. PEDOT nanostructures with two different morphologies (nanoparticles and nanowires) were synthesized. The size for the nanoparticles was in the range 10 40 nm and the diameter of the nanowires was of ca. 200 nm. These nanostructures were blended with an insulating polymer matrix, poly(methyl methacrylate) (PMMA), to evaluate the dielectrical properties of the materials. The results of broadband dielèctric spectroscopy showed a strong correlation between the morphology of the nanostructure and the impr…

Self-Assembly of block copolymers into internally ordered microparticles

2020

Abstract Block copolymer (BCP) self-assembly is one of the most versatile concepts for the bottom-up design of functional nanostructures in materials science, nanomedicine and nanotechnology. While BCPs have been extensively studied regarding their microphase separation in bulk and the self-assembly in solution, only recently BCPs were investigated for their ability to form internally ordered microparticles. In this review, we discuss two emerging concepts: (i) the microphase separation of BCPs in the spherical confinement of evaporating emulsion droplets and (ii) the self-assembly of highly asymmetric BCPs under concentrated conditions. While the first concept yields solid and compact mult…

Hybrid aerosol assisted atmospheric pressure Chemical Vapour Deposition: a facile route toward nano-composite thin films?

2009

A hybrid chemical vapour deposition strategy is presented as a facile route for the production of vanadium dioxide nano-composite thin films. The effect of the inclusion of gold nano-particles and the use of a surfactant molecule; tetraoctylammonium bromide (TOAB), is discussed. The films are fully characterised and it is shown that micro-structural changes lead to an enhancement of thermochromic properties, whilst gold nano-particles lead to a change in the films optical properties. Optical data is used in energy modelling studies to elucidate the films potential as an energy saving coating in architectural glazing.

Controlling electrical percolation in multicomponent carbon nanotube dispersions

2011

Carbon nanotube reinforced polymeric composites can have favourable electrical properties, which make them useful for applications such as flat-panel displays and photovoltaic devices. However, using aqueous dispersions to fabricate composites with specific physical properties requires that the processing of the nanotube dispersion be understood and controlled while in the liquid phase. Here, using a combination of experiment and theory, we study the electrical percolation of carbon nanotubes introduced into a polymer matrix, and show that the percolation threshold can be substantially lowered by adding small quantities of a conductive polymer latex. Mixing colloidal particles of different …

Multiwalled carbon nanotube reinforced polymer composites

2008

Due to their high stiffness and strength, as well as their electrical conductivity, carbon nanotubes are under intense investigation as fillers in polymer matrix composites. The nature of the carbon nanotube/polymer bonding and the curvature of the carbon nanotubes within the polymer have arisen as particular factors in the efficacy of the carbon nanotubes to actually provide any enhanced stiffness or strength to the composite. Here the effects of carbon nanotube curvature and interface interaction with the matrix on the composite stiffness are investigated using micromechanical analysis. In particular, the effects of poor bonding and thus poor shear lag load transfer to the carbon nanotube…