Search results for " NANOTUBES"
showing 10 items of 289 documents
From CeO2 Nanotubes to Nanowires through Electrogeneration of Base
2009
Abstract not Available.
Reversible self-assembly of metal chalcogenide/metal oxide nanostructures based on Pearson hardness.
2010
Nanotechnology has reached a stage of development where not individual nanoparticles but rather systems of greater complexity are the focus of concern. These complex structures incorporate two or more types of materials, an example of which is the formation of metal–semiconductor hybrids, which effectively combine the properties of both materials. The assembly of multicomponent nanoparticles from constituents with different optical, electrical, magnetic, and chemical properties can lead to novel functionalities that are independent of the individual components and may be tailored to fit a specific application. These applications include such far-reaching challenges as solar energy conversio…
High performance PA6/CNTs nanohybrid fibers prepared in the melt
2012
Commercial and home-made carbon nanotubes (CNTs) were plasma treated under oxygen atmosphere and then added to polyamide 6 (PA6) in order to prepare fibres by melt spinning. For comparison, pristine nanofillers were used too. The effect of functionalization and of filler characteristics on the morphological, rheological, mechanical and electrical properties of the fibres was studied by TEM and SEM, rheological measurements, tensile and electrical conductivity tests. The results demonstrated that the functionalization led to a better mechanical performance and the morphological analysis confirmed that the adhesion, the dispersion and the alignment of the nanotubes within the polymer matrix w…
From ceria nanotubes to nanowires through electrogeneration of base
2009
The preparation of Ce(OH)3/CeO2 nanostructures (NSs) through electrogeneration of base into anodic alumina membranes was studied. The effects of solvent (alcohol and/or water), Ce3? partner anion nature (chloride or nitrate) and concentration, applied potential or current density in driving the morphology toward nanowires (NWs) and/or nanotubes (NTs) was described. The structural analysis performed by X-Ray Diffraction and Raman Spectroscopy allowed to evidence that the presence of Ce(IV) into the nanostructures strongly depends on the oxygen content in the growing environment.
Nanoclays for Conservation
2019
Within the conservation of artworks materials, this chapter describes innovative strategies based on clay nanoparticles that are promising for protective coating, surface cleaning, and consolidation. We present the preparation of polymer/montmorillonite nanocomposites, which are revealed as efficient protective coatings for highly porous stones, marbles, and bread-made artifacts. Anticorrosive films for metal substrates have been obtained by polymer filling with laponite and halloysite nanotubes (HNTs) containing corrosion inhibitors into their lumen. The dispersion of hydrophobically modified HNTs into chitosan matrix drives to fabricate biofilms with surface cleaning capacity. Rust stains…
Numerical model for composite material with polymer matrix reinforced by carbon nanotubes
2008
Due to the high stiffness and strength, as well as their ability to act as conductors, carbon nanotubes are under intense investigation as fillers in polymeric materials. 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 nanocomposite. Here the effects of carbon nanotube curvature and interface interaction with the matrix on the nanocomposite stiffness are investigated using nanomechanical analysis. In particular, the effects of poor bonding and thus poor shear lag load transfer to the carbon nano…
Enhancing the mechanical performance of polymer based nanocomposites by plasma-modification of nanoparticles
2012
Abstract The possibility of enhancing the mechanical performance of two different polymer-based nanocomposites using polyamide 6 (PA6) and poly[ethylene-co-(vinyl acetate)] (EVA) as matrices was investigated. The nanofillers used were, respectively, either carbon nanotubes (CNTs) or an organically modified montmorillonite (Cloisite 15A), both previously modified by plasma treatment to introduce polar moieties. The nanofillers were fully characterized by Raman spectroscopy, XPS, FT-IR and XRD, demonstrating their effective modification with oxygenated groups. The nanocomposites were prepared by melt processing in order to obtain films and fibres. The mechanical tests carried out on the nanoc…
Halloysite nanotubes as polyolefin fillers
2015
Artykuł stanowi przegląd najnowszej literatury dotyczącej nanokompozytów poliolefinowych napełnianych nanorurkami haloizytowymi (HNT). Omówiono wpływ dodatku HNT na osnowę poliolefinową, ze szczególnym uwzględnieniem morfologii oraz właściwości mechanicznych nanokompozytów poliolefina/HNT. Modyfikowane HNT wykazywały wysoki stopień rozproszenia w osnowie poliolefinowej, dzięki czemu powodowały poprawę właściwości mechanicznych poliolefinowych nanokompozytów napełnianych nanorurkami haloizytowymi. Połączenie korzystnych właściwości poliolefin, ekonomicznych metod ich przetwórstwa oraz unikatowych w³aoeciwooeci HNT pozwoli na szersze rozpowszechnienie nanokompozytów wytworzonych z ich udziałe…
Biocompatible Poly(N-isopropylacrylamide)-halloysite Nanotubes for Thermoresponsive Curcumin Release
2015
The grafting of poly(N-isopropylacrylamide) (PNIPAAM) onto the halloysite external surface is proposed in order to obtain a novel thermoresponsive drug carrier for curcumin delivery. The new nanomaterial is characterized by means of FT-IR spectroscopy, thermogravimetric analysis, and SEM investigations. A high density of polymer chain was achieved at the nanoparticle surface. The PNIPAAM dehydration phenomenon was observed in water above 32 °C that is nearly coincident with the lower critical solution temperature for the polymer. The colloidal stability as well as the wettability of the obtained nanomaterial may be triggered by temperature stimuli. In vitro tests simulating the gastro-intes…
Nanocomposite, an innovative route to large structure and infrastructure protection. A case of study: CNT-doped polyurea
2010
<p>In this work we focus on experimental studies of polymer-nanocomposites intended for passive protection of civil structures. The material consists of a polyurea-matrix enhanced by different quantities of multiwalled carbon nanotubes. Several tensile and cyclic tests are performed to evaluate and characterize the mechanical behaviour of this new material. Furthermore, we subject the material to accelerated thermal aging and study its performance deterioration which is fairly unknown. The results on the unaged specimens are intuitive and indicate that an arbitrary amount of CNTs may result in suboptimal performance. More specifically, 1% in weight of CNTs yields the best mechanical p…