Carbon-Dot-Containing Poly(methyl methacrylate) for Highly Dielectric Nanomaterials

Abstract

In this paper, we report a massive enhancement of the relative permittivity of PMMA-based nanodielectrics in the presence of carbon dots (CDs) and neodymium-doped carbon dots (Nd-CDs). Different weight percentages (0.5, 5, and 10 wt %) of CDs and Nd-CDs were composited with PMMA to form PMMA@CD and PMMA@Nd-CD nanocomposite films, and films were characterized by different techniques. The dielectric response study indicates the significant enhancement of the relative permittivity of PMMA in the presence of CDs (∼15 times), and this value is increased further in the presence of Nd-CDs (∼153 times). The presence of many interfaces inside the PMMA@CD composites due to nanofillers is the cause of this significant enhancement in dielectric permittivity, which is further increased in the presence of Nd-CDs. As the temperature increases, the effective dipolar polarization of the composites increases, which in turn helps enhance relative permittivity. Nevertheless, at 75 °C and 100 Hz, the relative permittivity value for PMMA@Nd-CD composites reaches nearly 1242 (234 times), the highest reported for PMMA composites to date. Moreover, the AC conductivity for PMMA@Nd-CD is higher than that for PMMA@CD, possibly as a result of more charge conduction from the valence band to the conduction band for PMMA@Nd-CD. The conductivity is also increased as a function of temperatures for all composites as a result of the decrement of electronic resistance inside semiconductor nanofillers. In this study, a unique and sensitive change in dielectric and electrical properties of PMMA-based nanodielectrics was observed, which is helpful in the commercial use of PMMA nanodielectrics inside capacitors.

Functional and ultrastretchable thermoplastic elastomeric materials: Influence of carbon dots on fluorescence, dielectric and mechanical properties

“…Bhuyan et al reported the high dielectric nanocomposite of CDs‐based poly(methyl methacrylate). A massive enhance in the dielectric property of resulting composites with CDs by doping with neodymium was observed by Bhuyan et al 41 Despite of some progress with functional polymer composites based on CDs, there is very few literature reporting progress with functional thermoplastic elastomeric composite based on CDs. Thermoplastic elastomers (TPE) are elastomeric materials with both hard and soft phases, the soft phase providing elasticity and the hard phase contributing to processability.…”

“…The authors found that the loading of 1 wt% CDs in TPU matrix increased the tensile strength up to 57% compared with virgin TPU. 33 41 Despite of some progress with functional polymer composites based on CDs, there is very few literature reporting progress with functional thermoplastic elastomeric composite based on CDs. Thermoplastic elastomers (TPE) are elastomeric materials with both hard and soft phases, the soft phase providing elasticity and the hard phase contributing to processability.…”

Reduced Polyaniline-Modified NaNbO3 Nanowire/Polyetherimide Nanocomposites for Dielectric Capacitors with Enhanced Dielectric Properties and High Thermal Stability

“…Due to the rapid development of highly miniaturized electronic devices that require more film capacitors with millisecond charging/discharging capacity, there is a great need for high-energy-storage-density polymer film capacitors. − As a core component of a dielectric capacitor, dielectric materials are also required with stable operation capacity in extreme environments for an electromagnetic energy storage system. − Therefore, polymer film capacitors should be concurrently endowed with high E b , low dielectric loss, and excellent processing characteristics. − …”