Investigation of elastic constants of polymer/nanoparticles composites using the Brillouin spectroscopy and the mechanical homogenization modeling

A numerical model using homogenization techniques is proposed to simulate the evolution of elastic properties of nanocomposite polymer-nanoparticles, depending on the concentration of nanoparticles and the rigidity of the particle-matrix interface. To validate this model, it was confronted to several physical systems having different interface behavior, the nanocomposite systems: poly(vinylidene fluoride trifluoroethylene)/[A1.sub.2][0.sub.3] (alumina nanoparticles incorporated into copolymer of vinylidene difluoride and trifluoroethylene to form nanocomposite), PMMA/CNT (carbon nanotube/poly(methyl methacrylate) composite) and PMMA/Si[0.sub.2] with nanoparticles with or without surface treatment of silanization. For all these systems, the Young's modulus (nanoparticles and matrix) has been obtained experimentally from the elastic modulus [C.sub.11] obtained by Brillouin spectroscopy. These macroscopic measurements coupled with the theoretical model allow a multiscale approach of the elastic behavior of nanocomposite systems, providing information on the global elastic properties of polymer-nanoparticle material, and also indications about the strength of physical and chemical bonds between the nanoparticles and the matrix. Our results validate the hypothesis of the crucial role of the interface module, provided by numerical simulation which shows that incorporation of nanoparticles may lead to a strengthening or a weakening of the matrix. POLYM. ENG. SCI., 53: 1502-1511, 2013. [C] 2012 Society of Plastics Engineers
INTRODUCTION The power of nanotechnology is rooted in its potential to transform and revolutionize multiple technology and industry sectors, including aerospace, agriculture, biotechnology, energy, environmental improvement, information technology, medicine, and [...]