Search results for " nanoparticle"
showing 10 items of 936 documents
Au38Q MBTR-K3
2020
Purpose The purpose of Au38Q MBTR-K3 is to test the scalability of a machine learning regression model when the number of observations and the number of features change. Background The Au38Q MBTR-K3 was created from a trajectory file regarding the density functional theory simulation of Au38Q hybrid nanoparticle performed by Juarez-Mosqueda et al. in their paper Ab initio molecular dynamics studies of Au38(SR)24 isomers under heating using the MBTR descriptor by Himanen et al. as presented in paper DScribe: Library of descriptors for machine learning in materials science. The MBTR was used with the default parameters for K=3 (angles between atoms) presented at the website of Dscribe vers…
Pluronic nanoparticles as anti-oxidant carriers for polymers
2016
Abstract The immobilization of anti-oxidant stabilizers for polymers, particularly naturally occurring systems, can be considered a valuable route for preventing their migration, volatilization, thermo-degradation and decomposition at typical high processing temperatures, as well as for enhance their solubility in polymers. In this work, an innovative approach for the immobilization of naturally occurring stabilizer, through the encapsulation in copolymer nanoparticles, is proposed. Pluronic nanoparticles (PNPs), based on PEO-PPO-PEO, (PEO: poly (ethylene oxide); PPO: poly(propylene oxide)), without and with quercetin, Q, have been successfully formulated and the critical micellar condition…
Synergy of Miniemulsion and Solvothermal Conditions for the Low-Temperature Crystallization of Magnetic Nanostructured Transition-Metal Ferrites
2017
Crystalline first-row transition-metal (Mn, Fe, Co, Ni, Cu, and Zn) ferrites were prepared by an unprecedented synergetic combination of miniemulsion synthesis and solvothermal route, pursuing unconventional conditions in terms of space confinement, temperature, and pressure. This synergy allowed for obtaining six different crystalline ferrites at much lower temperature (i.e., 80 °C) than usually required and without any postsynthesis thermal treatment. X-ray diffraction (XRD) revealed that analogous ferrites synthesized by miniemulsion at ambient pressure or in bulk (i.e., from an aqueous bulk solution and not in the confined space of the miniemulsion droplets) either at ambient pressure o…
Synthesis of yttrium aluminum garnet nanoparticles in confined environment II: Role of the thermal treatment on the composition and microstructural e…
2017
Abstract Nanoparticles of yttrium aluminum garnet (YAG, Y 3 Al 5 O 12 ) have been obtained by thermal treatments, at several temperature in the range 400–950 °C, of the precursors synthetized via co-precipitation in water in oil microemulsion. The obtained nanoparticles have been characterized by means of X-ray Diffraction and Transmission Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (EDS) and Select Area Electron Diffraction (SAED). Results show the phase evolution occurring to obtain not aggregated nanoparticles of YAG phase. A possible growth mechanism of YAG nanoparticles is discussed on the basis of observed particle microstructure and morphology. The results i…
Structural and luminescence properties of amorphous SiO2 nanoparticles
2011
We report an experimental study on the photoluminescence band peaked at 2.7 eV (blue band) induced by thermal treatments in nanometric amorphous SiO 2. In particular the emission dependence on the nanometric particles size as a function of their mean diameter from 7 nm up to 40 nm is investigated. We found that the emission amplitude increases on decreasing the particle diameter, showing a strong correlation between the blue band and the nanometric nature of the particles. By Raman spectroscopy measurements it is evidenced that the SiO2 nanoparticles matrix is significantly affected by the reduction of size. Basing on the shell-like model, these findings are interpreted assuming that the de…
Organic-inorganic nanocomposites prepared by reactive suspension method: investigation on filler/matrix interactions and their effect on the nanopart…
2017
Epoxy resin/TiO2 nanocomposites prepared by both reactive suspension method, based on in situ synthesis, and conventional mechanical mixing are analysed by solid-state nuclear magnetic resonance and transmission electron microscopy in order to have a deeper insight into the nature of interactions at the polymer/particle interface and their effect on the nanoparticles dispersion. Specifically, solid-state nuclear magnetic resonance experiments showed that the nanoparticles, synthesized by reactive suspension method, can efficiently link the matrix by hydrogen bonds forming a hybrid organic-inorganic 3D network. Such evidences strongly supports our previously reported theory, in which the nan…
Applicability of a Polymerized Ionic Liquid/Carbon Nanoparticle Composite Electrolyte to Reductive Cyclization and Dimerization Reactions
2016
Abstract Recently, a reusable polymerized ionic liquid/carbon nanoparticle composite electrolyte was developed and effectively applied to a variety of oxidative transformations. The efficient recovery of the composite material and its application in subsequent electroorganic conversions without sacrificing yield adds to the sustainability of the protocol. Herein, we describe our efforts to expand the operational window of the composite electrolyte to include cathodically initiated processes occurring at potentials up to −2.6 V. The results indicate that the composite electrolyte is applicable to reductive processes, but the scope of transformations appears to be limited.
Design of cost-efficient and photocatalytically active Zn-based MOFs decorated with Cu 2 O nanoparticles for CO 2 methanation
2019
<div>Here we show for the first time a MOF that is photocatalytically</div><div>active for the light-assisted CO<sub>2</sub> methanation at mild conditions</div><div>(215 °C) without the inclusion of metallic nanoparticles or any</div><div>sacrificial agent. The presence of Cu<sub>2</sub>O nanoparticles causes a 50 % increase in the photocatalytic activity. These results pave the way to developping efficient and cost-effective materials for CO<sub>2</sub> elimination.</div>
Not always what closes best opens better: mesoporous nanoparticles capped with organic gates
2019
ABSTRACT Four types of calcined MCM-41 silica nanoparticles, loaded with dyes and capped with different gating ensembles are prepared and characterized. N1 and N2 nanoparticles are loaded with rhodamine 6G and capped with bulky poly(ethylene glycol) derivatives bearing ester groups (1 and 2). N3-N4 nanoparticles are loaded with sulforhodamine B and capped with self-immolative derivatives bearing ester moieties. In the absence of esterase enzyme negligible cargo release from N1, N3 and N4 nanoparticles is observed whereas a remarkable release for N2 is obtained most likely due to the formation of an irregular coating on the outer surface of the nanoparticles. In contrast, a marked delivery i…
NANOPARTICLES BASED ON NOVEL AMPHIPHILIC POLYASPARTAMIDE COPOLYMERS
2010
In this article, the synthesis of two amphiphilic polyaspartamide copolymers, useful to obtain polymeric nanoparticles without using surfactants or stabilizing agents, is described. These copolymers were obtained starting from α,β-poly-(N-2-hydroxyethyl)-dl-aspartamide (PHEA) by following a novel synthetic strategy. In particular, PHEA and its pegylated derivative (PHEA-PEG2000) were functionalized with poly(lactic acid) (PLA) through 1,1′-carbonyldiimidazole (CDI) activation to obtain PHEA–PLA and PHEA-PEG2000–PLA graft copolymers, respectively. These copolymers were properly purified and characterized by 1H-NMR, FT-IR, and Size Exclusion Chromatography (SEC) analyses, which confirmed that…