Optical and dielectric properties of PMMA (poly(methyl methacrylate))/carbon dots composites

Abstract

The optical and the dielectric properties of an original nanocomposite based on the incorporation of carbon dots (C‐dots) in poly(methyl methacrylate) (PMMA) at several filler loading were studied. The optical characterization demonstrated the preservation of the excitation dependent intense emission of the C‐dots in the polymer, ascribed to the presence of organic fluorophores formed during the nanoparticle synthesis. The composite PMMA/C‐dots dielectric properties were investigated in the frequency range from 40 Hz to 1 MHz and over the temperature range from 200 to 400 K. The dielectric response was obtained using the complex permittivity or the modulus formalisms, depending on the concentration of filler in the polymer matrix. A relaxation phenomenon was induced by the incorporation of the C‐dots in the PMMA matrix. In addition, both the real and imaginary parts of the dielectric permittivity and electric modulus changed with the volume fraction of the C‐dots, suggesting that the presence of the fillers greatly affect the dielectric properties of the polymer matrix because of polarization phenomenon induced by the nanoparticles. POLYM. COMPOS., 40:E1312–E1319, 2019. © 2018 Society of Plastics Engineers

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

“…As reported in our previous works, upon the incorporation in PMMA matrix the morphological and optical properties of C‐dots remain unchanged, sincenanoparticles appear to retain their size and shape in the nanocomposites blend and preserve their characteristic optical properties, both in solution and in freestanding films.…”

“…Previous work reported that the results of an analysis of experimental data to extract information about the dielectric relaxation and the electric modulus of PMMA/C‐Dots nanocomposites . This study showed that the electric modulus formalism was capable of revealing the interfacial relaxation, which, in most cases, is covered by the conductivity of the material when represented in the dielectric permittivity mode.…”

“…Chen and Feng functionalized the C‐Dotsby copolymerizing them with methacrylate to improve the compatibility between carbon nanofiller and PMMA, and the photoluminescence properties were studied. In our previous work, we studied the optical and dielectric properties of PMMA/C‐Dots nanocomposites at increasing filler loading . The optical measurements showed that C‐Dots retained their optical features in the obtained solid nanocomposites films, while a relaxation process was observed by the dielectric investigation, revealing that C‐Dots slightly interact with the polymeric host.…”

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

“…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 ].…”

Chitosan based fibers embedding carbon dots with anti‐bacterial and fluorescent properties

“…The size of C‐dots can vary from few nm to tens of nanometers, and be doped with several elements such as N, S, P, and B in imparting new functional properties 30 . C‐dots also have exceptional properties, as they are biocompatible, high aqueous solubility, and great photoluminescence properties 30,31 . Moreover, the fabrication of C‐dots is facile and economical with intrinsic favorable characteristics in many applications including drug delivery, photocatalyst, antibacterial material, biosensor, and bioimaging 30–32 .…”