Spontaneous Assembly of Carbon-Based Chains in Polymer Matrixes through Surface Charge Templates
Authors: Gennari O., Grilli S., Coppola S., Pagliarulo V., Vespini V., Coppola G., Bhowmick S., Gioffré M. A., Gentile G., Ambrogi V., Cerruti P., Carfagna C., Ferraro P.
Autors Affiliation: National Institute of Optics, National Council of Research of Italy, Via Campi Flegrei 34, 80078 Pozzuoli, Italy; Institute of Microelectronics and Microsystems, National Council of Research of Italy, Via Pietro Castellino, Napoli, Italy; Institute of Polymer Chemistry and Technology, National Council of Research of Italy, Via Campi Flegrei 34, 80078 Pozzuoli, Italy; Department of Chemical, Materials and Production Engineering, University of Naples, Piazzale Tecchio, 80125 Naples, Italy
Abstract: Stable chains of carbon-based nanoparticles were formed directly in polymer matrixes through an electrode-free approach. Spontaneous surface charges were generated pyroelectrically onto functionalized ferroelectric crystals, enabling the formation of electric field gradients that triggered the dipole-dipole interactions responsible for the alignment of the particles, while embedded in the polymer solution. The phenomenon is similar to the dielectrophoretic alignment of carbon nanotubes reported in the literature. However, here the electric fields are generated spontaneously by a simple heat treatment that, simultaneously, aligns the particles and provides the energy necessary for curing the host polymer. The result is a polymer sheet reinforced with well-aligned chains of carbon-based particles, avoiding the invasive implementation of appropriate electrodes and circuits. Because polymers with anisotropic features are of great interest for enhancing the thermal and/or the electrical conductivity, the electrode-free nature of this technique would improve the scaling down and the versatility of those interconnections that find applications in many fields, such as electronics, sensors, and biomedicine. Theoretical simulations of the interactions between the particles and the charge templates were implemented and appear in good agreement with the experimental results. The chain formation was characterized by controlling different parameters, including surface charge configuration, particle concentration, and polymer viscosity, thus demonstrating the reliability of the technique. Moreover, micro-Raman spectroscopy and scanning electron microscopy were used for a thorough inspection of the assembled chains.
Volume: 29 (50) Pages from: 15503 to: 15510
More Information: The authors acknowledge the Italian Ministry of Research for financial support, under the \”Futuro in Ricerca 2010\” Programme (Protocol RBFR10FKZH) and EFOR-CABIR CNR project.DOI: 10.1021/la403603dCitations: 11data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-01-12References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here