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Silicon carbide nanopowders (SiC_PL) were prepared via thermal plasma synthesis. The electrocatalytic activity of the SiC_PL coated glassy carbon electrode (GCE) towards the electrochemical oxidation of dopamine (DA), ascorbic acid (AA), and uric acid (UA), was characterized by cyclic voltammetry (CV), in 0.1 M phosphate buffer solution (PBS) at pH 7. The peaks of oxidation for DA, AA, and UA result well separated on the modified electrode in contrast with the behavior shown on bare GCE. A low limit of detection (LOD) of 0.043 μM was found at the SiC_PL coated GCE. In a real sample, the recovery rates of the added compound were 98.8%, 106.5% and 100.7%, indicating a potential for the SiC_PL electrode to determine DA in real conditions. The results of the characterization as supercapacitor electrode show that the specific capacitance for SiC_PL is of 151.2 F/g at 0.12 A/g. After 2.5 × 105 cycles SiC electrode still retains about 90% of its initial capacitance showing good stability.

In this work, the introduction of small variations in the electrical impedance ofHF (High Frequency) RFID (Radio Frequency Identification) tags has been exploited in the proximity sensing of temperature by applying Polyvinylidene Fluoride (PVDF) interdigital capacitive sensors as a modification of the transponder’s circuitry. The adopted electrical parasitic sensing load introduces a shift in the primary resonance peakof the tag. Theimpedance spectra have been acquired by a dedicated laboratory setup allowing to apply simultaneously thermal forcing and RF signals to the transponder itself. Thesensitivity of the modified taghas been assessed after taking into account the thermal response of the transponder chipwhich is relevant in the formulation of thermal-sensing transponders.

This work shows a method to fabricate interdigital capacitors having tunable sensitivity to temperature and stable behavior pointing to the application of ionic liquids (ILs) as fundamental building blocks in capacitive devices for temperature sensing in proximity conditions. Polyvinylidene fluoride (PVDF) in blend with 1-Butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) has been deposited by drop-casting from a N,N-dimethylformamide solution to be utilized as dielectric material in screen-printed interdigitated capacitors. Capacitance and conductance trends versus temperature have been analyzed and compared to bare PVDF dielectrics. The inclusion of [BMIM][PF6] in PVDF-IL blends increases the AC capacitance of the device and its sensitivity to the temperature in the examined range (+20 °C to +110 °C). AC measurements performed at 100 kHz have shown good electrical stability for PVDF-IL blends also when measured in ambient atmosphere. As a drawback, an increase in [BMIM][PF6] concentration resulted also in an increase in AC conductance which exhibits an Arrhenius activation with temperature. Such behavior has been attributed to the increase in ion concentration and ionic mobility with temperature. The work also shows the presence of a limit value for the activation energy of AC conductance for higher concentrations of the ionic liquid.

Poly(L-lactide) (PLLA) is a semicrystalline, biocompatible and biodegradable polymer widely employed in many applications (food packaging, biomedical devices, drug delivery systems). This work deals with nanocomposites of PLLA and tungsten disulfide (WS2) nanotubes (NTs) as a novel material to obtain thinner and stronger bioresorbable vascular scaffolds. We studied the influence of WS2 NTs on the mechanical properties of PLLA-WS2 films. Polarized optical microscopy reveals a high degree of orientation of the polymer molecules in stretched films that further increases with a post-stretching annealing treatment. At the same time, X-ray diffraction (XRD) and Raman spectroscopy confirm enhancement of the crystallinity induced by the WS2 NTs. © 2018 Author(s).

POC polymer is an oxadiazole-carbazole copolymer we have previously synthetized and established as light emitting material in Organic Light Emitting Devices (OLEDs), although POC quantum yield emission efficiency and color purity still need to be enhanced. On the other hand, tris[2-phenylpyridinato-C2,N]iridium(III) (Ir(ppy)3) complexes, namely Ir(ppy)3 are among the brightest luminophores employed in green light emitting devices. Our aim, in this work, is to take advantage of Ir(ppy)3 bright emission by combining the Ir complex with blue emitting POC to obtain tunable light emitting composites over a wide range of the visible spectrum. Here we have investigated the optical proprieties POC based nanocomposites with different concentrations of Ir(ppy)3, ranging from 1 to 10 wt%. Both spectral and time resolved fluorescence measurements show an efficient energy transfer from the polymer to the dopants, resulting in white-emitting composites. The most intense and stable emission has been found when POC was doped with about 5 wt% concentration of Ir(ppy)3. © 2016 Elsevier B.V.

This paper describes a straightforward strategy for the synthesis of new nitrogen chelates by employing the chirality of readily available sugars. Thus, diimino and diamino ligands can be attained easily by using the methyl-4,6- O -benzylidene-2,3-diazo-2,3-dideoxy-α- d -mannopyranoside skeleton. The coordinating ability of one ligand has also been assessed by preparing a square-planar palladium complex [PdCl 2 ( N , N -chelate)].

Two red emitters InP/ZnS quantum dots (QDs) (absorption 570 nm/emission 605 nm and absorption 597/emission 624) were inserted at different concentrations in the blue emitting polymer poly(9,9'- dioctylfluorene) (PFO). Nanocomposites were obtained by mixing the QDs as purchased and the polymer dissolved in the appropriate solvent and deposited by spin coating to give homogeneous films. The morphological properties were characterized by scanning electron microscopy (SEM), that showed a good level of dispersion of the QDs within the polymer. The study of the optical and electrooptical properties of the nanocomposites layer inserted in OLED devices (glass/ITO/PEDOT:PSS/PFO-QD/Ca/Al) is reported and compared to pure polymer based device. Photoluminescence and electroluminescence spectra show an energy transfer from the polymer to QDs in presence of the nanocomposites containing InP/ZnS quantum dots that absorb at 570 nm. © 2013 American Scientific Publishers.

In this work, we studied energetic and optical proprieties of a polyester-containing oxadiazole and carbazole units that we will indicate as POC. This polymer is characterized by high photoluminescence activity in the blue region of the visible spectrum, making it suitable for the development of efficient white-emitting organic light emission devices. Moreover, POC polymer has been combined with two red emitters InP/ZnS quantum dots (QDs) to obtain nanocomposites with wide emission spectra. The two types of QDs have different absorption wavelengths: 570 nm [InP/ZnS(570)] and 627 nm [InP/ZnS(627)] and were inserted in the polymer at different concentrations. The optical properties of the nanocomposites have been investigated and compared to the ones of the pure polymer. Both spectral and time resolved fluorescence measurements show an efficient energy transfer from the polymer to QDs, resulting in white-emitting nanocomposites. © Springer Science+Business Media Dordrecht 2013.

A new blue emitter oxadiazole/carbazole copolymer has been synthesized and combined with CdSe/ZnS quantum dots (QDs). Surface passivation of the QDs by ionic liquids was crucial to improve their compatibility with the polymer allowing the deposition of homogeneous nanocomposites films. The nanocomposites have been characterized by thermogravimetric analysis, infrared, UV–visible absorption, and photoluminescence spectroscopy. The emission spectra of nanocomposites show a wide spectrum from blue to orange wavelengths due to the combination of colors emitted by the polymer and QDs, respectively. POLYM. COMPOS., 34:1471–1476, 2013. © 2013 Society of Plastics Engineers