Abstract—Exposure to ionizing radiation has been found to induce changes in poly(vinylidene fluoride) (PVDF) homopolymers. The high dose gamma irradiation process induces the formation of C=C and C=O bonds in its [CH2-CF2]n main chain. The irradiation also provokes crosslinking and chain scission. All these radio- induced defects lead to changes in the PVDF crystalline structure. As a consequence, it is common to observe a decrease in the melting temperature (TM) and melting latent heat (LM) and some changes in its ferroelectric features. We have investigated the possibility of preparing nanocomposites of PVDF with graphene oxide (GO) through the radio-induction of molecular bonds. In this work, we discuss how the gamma radiation interacts with the nanocomposite crystalline structure. Keywords—Gamma irradiation, grapheme oxide, nanocomposites, PVDF. I. INTRODUCTION HE modification of polymers with ionizing radiation is a field that has developed considerably, leading to numerous technological applications. PVDF, for example, has been the focus of several studies due to its applications as a biocompatible material and ferroelectric properties, with important applications in the pharmaceutical, aerospace, electronics, and food industries. One of the four possible crystalline phases of PVDF, namely phase II or β-phase, shows ferroelectricity, making this homopolymer very attractive for technological applications [1]. The search for polymer nanocomposites with GO loading aims to obtain materials with new properties. In the case of materials subjected to gamma irradiation, it is expected to be able to produce materials that support exposure to high doses, with lower radio-degradation. Industries such as aerospace and aeronautics are examples where there is demand for radio- resistant materials to electromagnetic radiation [2]. Biomaterials are also exposed to gamma radiation for pre-use sterilization in in vivo contact. In addition, there are situations of use that simultaneously lead to the exposure to radiation and high temperatures, which justifies the understanding of the thermal degradation processes of these materials. Juliana V. Pereira, and Adriana Souza M. Batista are with the Universidade Federal de Minas, Belo Horizonte, MG 31270-970 Brasil (phone: 55-31-3409- 6666, 31-55-3409-9770; fax: 55-31-3409-6660,31-55-3409-9770; e-mail: julianaviegas1@yahoo.com.br, adriananuclear@yahoo.com.br). Jefferson P. Nascimento, Clascídia A. Furtado, and Luiz O. Faria are with Serviço de Nanotecnologia e Materiais Nucleares, Belo Horizonte, MG 31270-901 Brasil, on leave from the Centro de Desenvolvimento da Tecnologia Nuclear, Minas Gerais, Brasil (e-mail: nascimentopatricio@ yahoo.com.br, clas@cdtn.br, farialo@cdtn.br). Nanoparticles with nanometer size, high surface area, and associated performance of interfaces can be used as structure and morphology directors of the nanocomposites. However, another nanoscaled material, the graphene sheets, has generated enormous interest for its possible implementation in many devices. Graphene is considered a two-dimensional carbon nanofiller, with a one-atom-thick planar sheet of carbon atoms that are densely packed in a honeycomb crystal lattice. To have remarkable properties [3], filling polymeric materials with graphene is an attempt to transfer their properties to the resulting nanocomposites [4]. In this study, PVDF pure samples and PVDF/GO nanocomposite are compared with respect to their resistance to gamma irradiation process. Thermal analysis allowed us to check an increase in thermal stability of nanocomposites relative to pure samples of PVDF. II. EXPERIMENTAL Samples of pure grain PVDF were made into thin films with a plate press heated to 200 o C at a pressure of 300 bar for 10 seconds, with subsequent air-cooling to room temperature. Nanocomposites were produced by mixing solved PVDF in DMAc with 1.88% GO dispersed in an aqueous solution by sonication. The PVDF pure samples produced by melt at 200 o C under 300 bar are shown in Fig. 1. Fig. 1 PVDF pure sample prepared by melt at 200 o C under 300 bar Fig. 2 shows scheme of the syntheses of the samples PVDF/GO. PVDF pure samples and the nanocomposites were irradiated in Gamma Irradiation Laboratory (LIG) of CDTN using a Co-60 source at constant dose rate (12.0 kGy/h), for doses ranging from 100.0 to 1000.0 kGy in a scheme like the one shown in Fig. 3. Radiation Effects in the PVDF/Graphene Oxide Nanocomposites Juliana V. Pereira, Adriana S. M. Batista, Jefferson P. Nascimento, Clascídia A. Furtado, Luiz O. Faria T World Academy of Science, Engineering and Technology International Journal of Chemical and Molecular Engineering Vol:11, No:2, 2017 178 International Scholarly and Scientific Research & Innovation 11(2) 2017 scholar.waset.org/1307-6892/10006538 International Science Index, Chemical and Molecular Engineering Vol:11, No:2, 2017 waset.org/Publication/10006538