Cluster microstructure and local elasticity of carbon‐epoxy nanocomposites studied by impulse acoustic microscopy

Abstract

The impulse acoustic microscopy method was applied to observe the bulk microstructure and to measure sonic velocities and elastic moduli in the carbon nanocomposite specimens prepared by a traditional method and with the use of a vacuum mixer. It is shown that carbon nanoparticles tend to cluster and form micron‐sized aggregates. The impulse acoustic microscopy technique makes it possible to visualize a non‐uniform distribution of carbon nanofillers over the specimen bulk. Both nanotube and nanoplatelets conglomerates are visible most likely due to the air containing. Results of the elastic measurements demonstrate homogeneity of elastic properties over the material bulk and a weak dependence of sonic velocities and elastic moduli on the filler content. Reduction of the air content and enhancement of elastic properties are observed when increasing the nanofiller content and employing the vacuum mixing technology in nanocomposite fabrication. POLYM. ENG. SCI., 57:697–702, 2017. © 2017 Society of Plastics Engineers

Modeling and Electrochemical Characterization of Electrodes Based on Epoxy Composite with Functionalized Nanocarbon Fillers at High Concentration

“…As previously demonstrated [ 17 ], the realization process, carried out by the ARV-310 planetary mixer, is powerful to prepare nanocomposite materials of high quality dispersion: The scanning electron microscopy (SEM) characterization, carried out by means of a Tescan Vega II microscope, highlights a good dispersion of all types of filler in the investigated range.…”

“…Furthermore, as the viscosity increases, mixing with a planetary mixer improves the efficacy. Therefore, we replace the ultrasounds tip with a supplementary step in ARV-310 to obtain a good homogeneity of mixture, as demonstrated in a previous work [ 17 ]. In fact, the ARV-310 generates a big centrifugal force during the planetary motion that is able to mix and de-aerate at the same time.…”

“…In the following figures we report the measured impedance (amber dots, outliers have been removed), together with the response of the electrical circuit as fitted by EIS Analyzer free software [ 17 ] (blue line) and by Matlab (red line).…”

“…The main aim of this paper is to propose a preparation method involving an ARV-310 vacuum planetary mixer (Thinky Corporation, Tokyo, Japan) in order to produce high quality and highly reproducible nanocomposites, reducing air bubbles, and increasing the homogeneity of the filler dispersion, even at a very high filler concentration. As known from the literature [ 16 , 17 ], the planetary centrifugal mixing action can help obtain a well dispersion in a short time and, operating at low pressure, to reduce the presence of air inside the matrix.…”

Carbon Nanotubes Dispersion Assessment in Nanocomposites by Means of a Pulsed Thermographic Approach

“…The poor dispersion and formation of bundles significantly limit the enhancements achievable by adding CNTs to the neat polymer. An NDE technique based on the impulse acoustic microscopy method, and that was able to control the quality of the graphene dispersion has been presented in literature [ 26 , 27 ]. They were used to control bulk microstructure in carbon nanocomposite samples with different levels of dispersion; however, this NDE method is slow and can only scan small samples, thus limiting possible industrial applications.…”