Search results for " Coating."
showing 10 items of 2558 documents
Statistical study of the influence of CNTs purification and plasma functionalization on the properties of Polycarbonate-CNTs nanocomposites
2014
This work reports a statistical study on the relationship between the chemical-physical properties of CNTs, which vary by changing the conditions of purification and plasma treatment, and the macroscopic properties of PC-based nanocomposites. CNTs are synthesized and then purified in two different ways and used as fillers for the preparation of PC/CNTs nanocomposites. In some cases, oxygen plasma treatment is carried out to improve their affinity to the matrix. The CNTs are characterized by TGA, ICP/OES and FT-Raman spectroscopy, titration and morphological analysis. Mechanical, dynamic-mechanical, electrical and morphological tests are used for characterizing PC/CNTs nanocomposites.
Ferritin-Coated SPIONs as New Cancer Cell Targeted Magnetic Nanocarrier
2023
Superparamagnetic iron oxide nanoparticles (SPIONs) may act as an excellent theragnostic tool if properly coated and stabilized in a biological environment, even more, if they have targeting properties towards a specific cellular target. Humanized Archaeoglobus fulgidus Ferritin (HumAfFt) is an engineered ferritin characterized by the peculiar salt-triggered assembly-disassembly of the hyperthermophile Archaeoglobus fulgidus ferritin and is successfully endowed with the human H homopolymer recognition sequence by the transferrin receptor (TfR1 or CD71), overexpressed in many cancer cells in response to the increased demand of iron. For this reason, HumAfFt was successfully used in this stud…
Bright Visible Luminescence in Silica Nanoparticles
2011
International audience; We demonstrate that a porous film of silica nanoparticles emits a bright visible luminescence associated with defects stabilized by oxygen chemisorption at oxygen deficient center sites. Time-resolved spectra excited by a tunable laser allow us to distinguish the luminescence at 1.99 eV, characteristic of the nonbridging oxygen hole center (NBOHC) (Si-O)3 Si-O*, and a fast and a slow emission: the first (lifetime τ ≈ 25 ns) is peaked at 2.27 eV with an excitation spectrum centered at 5.5 eV; the second (τ ≈ 7.5 μs) is peaked at 2.41 eV and is excited around 3.2 and 5.2 eV. Reaction in an air atmosphere leads to the disappearance of the NBOHC luminescence and of the …
Study of Intumescent Coatings Growth for Fire Retardant Systems in Naval Applications: Experimental Test and Mathematical Model
2022
Onboard ships, fire is one of the most dangerous events that can occur. For both military and commercial ships, fire risks are the most worrying; for this reason they have an important impact on the design of the vessel. The intumescent coatings react when heated or in contact with a living flame, and a multi-layered insulating structure grows up, protecting the underlying structure. In this concern, the aim of the paper is to evaluate the intumescent capacity of different composite coatings coupling synergistically modeling and experimental tests. In particular, the experiments have been carried out on a new paint formulation, developed by Colorificio Atria S.r.l., in which the active comp…
Optical Absorption of Excimer Laser‐Induced Dichlorine Monoxide in Silica Glass and Excitation of Singlet Oxygen Luminescence by Energy Transfer from…
2021
An optical absorption (OA) band of interstitial dichlorine monoxide molecules with peak at 4.7 eV and halfwidth 0.94 eV is identified in F2 laser - irradiated (photon energy=7.9 eV) synthetic silica glass bearing both interstitial O2 and Cl2 molecules. Alongside with intrinsic defects, this OA band can contribute to solarization of silica glasses produced from SiCl4. While the formation of ClClO is confirmed by its Raman signature, its structural isomer ClOCl may also contribute to this induced OA band. Thermal destruction of this band between 300C and 400C almost completely restores the pre-irradiation concentration of interstitial Cl2. An additional weak OA band at 3.5 eV is tentatively a…
Near‐IR Radiation‐Induced Attenuation of Aluminosilicate Optical Fibers
2021
The X-ray radiation-induced attenuation (RIA) growth kinetics are studied online in different single-mode aluminosilicate optical fibers in the near-IR (NIR) domain to evaluate their potential in terms of dosimetry. The optical fibers differ by Al contents, core sizes, drawing parameters, and also by a preform deposition process. The data show no dependence of the RIA on all these parameters, a positive result for the design of point or distributed radiation detectors exploiting RIA to monitor the dose. The RIA growth rate is unchanged for dose rates changing from 0.073 to 6.25 Gy(SiO2) s−1, and the RIA linearly increases with the dose up to 2 kGy(SiO2). Small but noticeable RIA changes are…
Silver Sulfide Nanoclusters and the Superatom Model
2015
The superatom model of electron-shell closings has been widely used to explain the stability of noble-metal nanoclusters of few nanometers, including thiolate-protected Au and Ag nanoclusters. The presence of core sulfur atoms in silver sulfide (Ag–S) nanoclusters renders them a class of clusters with distinctive properties as compared to typical noble-metal clusters. Here, it is natural to ask whether the superatom model is still applicable for the Ag–S nanoclusters with mixed metal and nonmetal core atoms. To address this question, we applied density functional simulations to analyze a series of Ag–S nanoclusters: Ag14S(SPh)12(PPh3)8, Ag14(SC6H3F2)12(PPh3)8, Ag70S16(SPh)34(PhCO2)4(triphos…
Mechanical and optical properties of as-grown and thermally annealed titanium dioxide from titanium tetrachloride and water by atomic layer deposition
2021
Funding Information: This work was carried out within the MECHALD project funded by Business Finland (Tekes) and is linked to the Finnish Centers of Excellence in Atomic Layer Deposition (ref. 251220) and Nuclear and Accelerator Based Physics (refs. 213503 and 251353) of the Academy of Finland. Funding Information: This work was carried out within the MECHALD project funded by Business Finland (Tekes) and is linked to the Finnish Centers of Excellence in Atomic Layer Deposition (ref. 251220 ) and Nuclear and Accelerator Based Physics (refs. 213503 and 251353 ) of the Academy of Finland. Publisher Copyright: © 2021 The use of thin-films made by atomic layer deposition (ALD) is increasing in …
Atomic layer deposition of AlN from AlCl3 using NH3 and Ar/NH3 plasma
2018
The atomic layer deposition (ALD) of AlN from AlCl3 was investigated using a thermal process with NH3 and a plasma-enhanced (PE)ALD process with Ar/NH3 plasma. The growth was limited in the thermal process by the low reactivity of NH3, and impractically long pulses were required to reach saturation. Despite the plasma activation, the growth per cycle in the PEALD process was lower than that in the thermal process (0.4A ° vs 0.7A ° ). However, the plasma process resulted in a lower concentration of impurities in the films compared to the thermal process. Both the thermal and plasma processes yielded crystalline films; however, the degree of crystallinity was higher in the plasma process. The…
Deposition and characterization of coatings of Hydroxyapatite, Chitosan, and Hydroxyapatite-Chitosan on 316L for biomedical devices
2018
In the last decades, the scientific community has turned on great interest towards the development of increasingly performing biomedical systems. In the orthopedic field, biomedical devices are made up by metallic materials (mainly steel and titanium alloys), which have low/medium resistance to corrosion and a low osteointegration capacity when implanted inside the human body. This can lead to infection or inflammation that can damage the tissues surrounding the implant. The use of biocompatible coatings allows cancelling or mitigating these phenomena. The coating interposing between aggressive environment and biomedical device inhibits corrosion so limiting the metal ions release into the …