Thermal properties and electric modulus approach to the analysis of dielectric relaxation of nanocomposites based on carbon dots

Bouknaitir, Ilham; Teixeira, S. Soreto; Kreit, L.; Panniello, Annamaria; Fini, Paola; Striccoli, Marinella; Costa, L. C.; Achour, M. E.

doi:10.1002/pc.25332

Cited by 8 publications

(5 citation statements)

References 35 publications

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“…[69]. As observed, loading NiO or La 2 O 3 decreases the values of M″ compared to the blend, which suggests the plurality of relaxation mechanisms in NiO and La 2 O 3 loaded films and this agrees with other works[70]. The variation of M″ with increasing ω could be analyzed according to the Kohlrauch-Williams-Watts equation[71], j = t b ( )…”

supporting

confidence: 85%

Influence of NiO and La₂O₃ nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study

Sayed¹,

El‐Gamal²

2022

Phys. Scr.

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Nano-sized metal oxides are fascinating materials as fillers used for improving the polymeric materials’ performance and expanding their multifunctionality. Two metal oxides; NiO and La2O3 nanoparticles (NP) were prepared and introduced into poly(vinyl acetate)/poly(methyl methacrylate), PVAc/PMMA blend via solution casting route. XRD and HR-TEM analysis confirmed the preparation of a cubic NiO and a hexagonal La2O3 NP with an average crystallite size of 59.85 and 29.13 nm, respectively. Introducing NiO and La2O3 increases the films’ amorphous structure. FTIR analysis confirmed the existence of all blend’ functional groups and hydrogen bond formation. SEM investigation showed that NiO or La2O3 loading affects the blend surface morphology. A UV-vis-NIR study showed that NiO narrowed the direct bandgap of the blend from 4.1 to 3.3 eV, whereas La2O3 reduced it to 3.4 eV. 1.0 wt.% NiO significantly improved the various optical constants of the blend. DMA revealed that storage modulus G' increased with loading of 1 wt.% NiO or La2O3 by 79.3% and 51.0%, respectively while G' decreased with heating. The dielectric behavior of films is analyzed using several dielectric parameters. The maximum σac reported for 1.0 wt.% NiO/blend film is 5.8×10–6 (S/cm). The AC conduction mechanism is discussed for all films in the temperature and frequency ranges (298−373 K) and (5 Hz−2 MHz). 1.0 wt.%/PVAc/PMMA nanocomposite showed enhanced optical and mechanical properties, making it suitable for architectural, flexible display screens, and photovoltaic cell devices. Moreover, loading NiO and La2O3 improved the dielectric properties of the blend to be used in the semiconductor industry, besides energy storage devices and supercapacitors.

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confidence: 85%

Influence of NiO and La₂O₃ nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study

Sayed¹,

El‐Gamal²

2022

Phys. Scr.

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“…Remarkably, such an improvement enables a fast synthesis of CDs, confirming the viability of such a unique synthetic strategy for producing CDs in a fast, reproducible, cost-effective and sustainable way. Finally, the dispersion in organic solvents allows the incorporation of the CDs into host polymers for nanocomposite preparation, and their fabrication as thin film [ 58 , 59 ] or further micromachining, thanks to the convenient film-forming properties of suitable organic solvents and their compatibility with clean room manufacturing. Such advanced processability paves the way for an effective integration of the luminescent CDs into photonic devices, LEDs or sensors [ 56 , 60 , 61 ].…”

Section: Discussionmentioning

confidence: 99%

Oil-Dispersible Green-Emitting Carbon Dots: New Insights on a Facile and Efficient Synthesis

et al. 2020

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Carbon dots (CDs) have been progressively attracting interest as novel environmentally friendly and cost-effective luminescent nanoparticles, for implementation in light-emitting devices, solar cells, photocatalytic devices and biosensors. Here, starting from a cost-effective bottom-up synthetic approach, based on a suitable amphiphilic molecule as carbon precursor, namely cetylpyridinium chloride (CPC), green-emitting CDs have been prepared at room temperature, upon treatment of CPC with concentrated NaOH solutions. The investigated method allows the obtaining, in one-pot, of both water-dispersible (W-CDs) and oil-dispersible green-emitting CDs (O-CDs). The study provides original insights into the chemical reactions involved in the process of the carbonization of CPC, proposing a reliable mechanism for the formation of the O-CDs in an aqueous system. The ability to discriminate the contribution of different species, including molecular fluorophores, allows one to properly single out the O-CDs emission. In addition, a mild heating of the reaction mixture, at 70 °C, has demonstrated the ability to dramatically decrease the very long reaction time (i.e. from tens of hours to days) at room temperature, allowing us to synthesize O-CDs in a few tens of minutes while preserving their morphological and optical properties.

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“…Where M′ and M″ are used to represent the real and imaginary parts of electric modulus respectively [55]. It has an inverse relation with the permittivity of the material as permittivity measures the opposition offered by the material against the formation of electric field [56].…”

Section: Modulus Of Electric Fieldmentioning

confidence: 99%

Effect of nickel substitution on structural and dielectric properties of Mg-Zn based spinel ferrite nanoparticles

et al. 2022

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Herein, we used sol-gel auto combustion technique for fabrication of the series of nickel substituted magnesium-zinc spinel ferrite (Mg0.3NixZn0.7-xFe2O4) nanoparticles by varying nickel concentrations as 0.00 ≤ x ≤ 0.20. X-ray diffraction (XRD) investigation evidenced that the synthesized nanomaterials are of spinel ferrite nature with secondary phase. Moreover, the crystallite size was observed to be in the range from 13 to 17 nm as estimated by Scherrer’s formula. It has been found that the structural parameters (e.g., bulk density, lattice constant, micro strain, crystallite size, surface area etc.) of the as-synthesized magnesium-zinc spinel ferrite nanoparticles have been strongly influenced by doping content of nickel. Moving further, we have investigated the dielectric properties of the prepared nanoparticles in the frequency range from 20 Hz to 20 MHz. The remarkable electric modulus, impedance and dielectric properties of the prepared spinel ferrites made these materials a potential candidate for low- and high-frequency applications.

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Thermal properties and electric modulus approach to the analysis of dielectric relaxation of nanocomposites based on carbon dots

Cited by 8 publications

References 35 publications

Influence of NiO and La₂O₃ nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study

Influence of NiO and La₂O₃ nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study

Oil-Dispersible Green-Emitting Carbon Dots: New Insights on a Facile and Efficient Synthesis

Effect of nickel substitution on structural and dielectric properties of Mg-Zn based spinel ferrite nanoparticles

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Thermal properties and electric modulus approach to the analysis of dielectric relaxation of nanocomposites based on carbon dots

Cited by 8 publications

References 35 publications

Influence of NiO and La2O3 nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study

Influence of NiO and La2O3 nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study

Oil-Dispersible Green-Emitting Carbon Dots: New Insights on a Facile and Efficient Synthesis

Effect of nickel substitution on structural and dielectric properties of Mg-Zn based spinel ferrite nanoparticles

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Product

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Influence of NiO and La₂O₃ nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study

Influence of NiO and La₂O₃ nanoparticles on the optical, mechanical and electrical properties of PVAc–PMMA blend: a comparative study