Search results for "nanocomposite"

Curing of an epoxy resin modified with nanoclay monitored by dielectric spectroscopy and rheological measurements

2006

Dielectric and rheological measurements have been performed in “real-time” to follow curing reaction on blends of a diglycidyl ether of bisphenol-A epoxy resin with 4,4-methylene bis(2,6-diethylaniline) hardener and different amounts of organically modified nanoclay (Nanofil 919) as modifier. The effect of the modifier and its amount on the curing reaction, as well as that of the curing temperature has been studied. Changes in molecular mobility in the reaction mixture have been investigated by dielectric relaxation spectroscopy. Evolutions of ionic conductivity and main relaxation have been analyzed and vitrification times have been obtained and compared with those obtained by rheological …

A Novel Approach Towards Carbon–Ru Electrodes with Mesoporosity for Supercapacitors

2007

The effect of silica nanoparticles on the morphology, mechanical properties and thermal degradation kinetics of PMMA

2012

Abstract Silica–PMMA nanocomposites with different silica quantities were prepared by a melt compounding method. The effect of silica amount, in the range 1–5 wt.%, on the morphology, mechanical properties and thermal degradation kinetics of PMMA was investigated by means of transmission electron microscopy (TEM), X-ray diffractometry (XRD), dynamic mechanical analysis (DMA), thermogravimetric analyses (TGA), Fourier-transform infrared spectroscopy (FTIR), 13 C cross-polarization magic-angle spinning nuclear magnetic resonance spectroscopy ( 13 C{ 1 H} CP-MAS NMR) and measures of proton spin-lattice relaxation time in the rotating frame ( T 1 ρ ( H )), in the laboratory frame ( T 1 ( H )) a…

Silanol-POSS as dispersing agents for carbon nanotubes in polyamide

2017

Silanol polyhedrad oligomeric silsesquiosane terminated with phenyl rings (phPOSS) has been considered as dispersing agent for carbon nanotubes (CNTs) in polyamide (PA) matrix. Two different approaches have been followed for the introduction of the phPOSS molecules: a “classical” approach which involves the introduction of the dispersing agent during the melt mixing, and an “innovative” approach, consisting in the immobilization, either covalent and non-covalent, of phPOSS molecules onto CNTs surface. The properties of PA-based nanocomposites, containing free phPOSS molecules and phPOSS molecules immobilized onto the CNTs outer surface, have been evaluated through rheological, mecha…

Pyrazole[3,4-d]pyrimidine derivatives loaded into halloysite as potential CDK inhibitors

2021

Uncontrolled cell proliferation is a hallmark of cancer as a result of rapid and deregulated progression through the cell cycle. The inhibition of cyclin-dependent kinases (CDKs) activities is a promising therapeutic strategy to block cell cycle of tumor cells. In this work we reported a new example of nanocomposites based on halloysite nanotubes (HNTs)/pyrazolo[3,4-d]pyrimidine derivatives (Si306 and Si113) as anticancer agents and CDK inhibitors. HNTs/Si306 and HNTs/Si113 nanocomposites were synthesized and characterized. The release kinetics were also investigated. Antitumoral activity was evaluated on three cancer cell lines (HeLa, MDA-MB-231 and HCT116) and the effects on cell cycle ar…

Generalized synthesis of periodic surfactant/inorganic composite materials

1994

THE recent synthesis of silica-based mesoporous materials1,2 by the cooperative assembly of periodic inorganic and surfactant-based structures has attracted great interest because it extends the range of molecular-sieve materials into the very-large-pore regime. If the synthetic approach can be generalized to transition-metal oxide mesostructures, the resulting nanocomposite materials might find applications in electrochromic or solid-electrolyte devices3,4, as high-surface-area redox catalysts5 and as substrates for biochemical separations. We have proposed recently6 that the matching of charge density at the surfactant/inorganic interfaces governs the assembly process; such co-organizatio…

Fluorescent Boron Oxide Nanodisks as Biocompatible Multi-messenger Sensors for Ultrasensitive Ni$^{2+}$ Detection

2023

Boron-based nanocomposites are very promising for a wide range of technological applications, spanning from microelectronics to nanomedicine. A large variety of B-based nanomaterials has been already observed, such as borospherene, B nanotubes and nanoparticles, and boron nitride nanoparticles. However, their fabrication usually involves toxic precursors or leads to very low yields or small boron atom concentration. In this work, we report the synthesis of nanometric B$_{2}$O$_{3}$ nanodisks, a family of nanomaterials with a quasi-2D morphology capable of intense fluorescence in the visible range. Such as boron-based nanomaterial, which we synthesized by pulsed laser ablation of a boron tar…

Aggregation-induced heterogeneities in the emission of upconverting nanoparticles at the submicron scale unfolded by hyperspectral microscopy

2018

Transparent upconverting hybrid nanocomposites are exciting materials for advanced applications such as 3D displays, nanosensors, solar energy converters, and fluorescence biomarkers. This work presents a simple strategy to disperse upconverting b-NaYF4:Yb3+/Er3+ or Tm3+ nanoparticles into low cost, widely used and easy-to-process polydimethylsiloxane (PDMS)-based organic–inorganic hybrids. The upconverting hybrids were shaped as monoliths, films or powders displaying in the whole volume Tm3+ or Er3+ emissions (in the violet/blue and green/red spectral regions, respectively). For the first time, hyperspectral microscopy allows the identification at the submicron scale of differences in the …

Effect of Graphene Nanoplatelets on the Physical and Antimicrobial Properties of Biopolymer-Based Nanocomposites

2016

In this work, biopolymer-based nanocomposites with antimicrobial properties were prepared via melt-compounding. In particular, graphene nanoplatelets (GnPs) as fillers and an antibiotic, i.e., ciprofloxacin (CFX), as biocide were incorporated in a commercial biodegradable polymer blend of poly(lactic acid) (PLA) and a copolyester (BioFlex®). The prepared materials were characterized by scanning electron microscopy (SEM), and rheological and mechanical measurements. Moreover, the effect of GnPs on the antimicrobial properties and release kinetics of CFX was evaluated. The results indicated that the incorporation of GnPs increased the stiffness of the biopolymeric matrix and allowed for the t…

Effect of polarity and elongational flow on the morphology and properties of a new nanobiocomposite

2015

Nanocomposites are a new class of biodegradable polymer materials with an ultrafine phase dispersion of the order of a few nanometers in a biodegradable polymer matrix that shows very interesting properties often very different from those of conventional filled polymers. In this work the effect of the polarity of the organomodified montmorillonite and of the elongational flow on the morphology and the rheological and mechanical properties of a new nanobiocomposite having as a matrix a biodegradable copolyester based bland has been investigated. The morphology of the nanocomposite with the more polar organomodified clay shows a more exfoliated morphology due to the major compatibility with t…