Desenvolvimento de nanocompósitos híbridos a partir de nanopartículas de magnetita funcionalizadas com macromoléculas de polietilenoglicol

Abstract

New technologies aim for new materials. The increase in search for new materials with hybrid properties is growing exponentially. Polymers, metals and ceramics may be exposed within their application areas, but they cover only part of the desired spectrum of properties. Thus, composite materials are produced for this purpose of multifunctionality. Within the class of composite materials, hybrid nanocomposites have attracted a great deal of attention from academia due to the number of properties and application that can be achieved using chemically designed materials at the molecular level. One of the most promising and challenging approaches is the synthesis of colloidal nanoparticles (NPs), which consists of a combination of a rigid inorganic core and a flexible organic corona. In this context, this study provides a systematic study of interparticle interactions on formation of macroscopic structures by hybrid nanocomposites based on magnetite nanoparticles (Fe3O4) grafted with Polyethylene glycol (PEG) at different molecular weight 3000 g.mol-1 and 6000 g.mol-1. By improving organic interactions, hybrid structures were produced by controlled evaporation of grafted nanoparticles colloid and consolidated by uniaxial pressure. All these steps were analyzed by Scanning Electron Microscopy (SEM). Based on this, rotational and oscillation rheometry were performed, providing interesting results about pseudoplastic behavior of these nanocomposites, as well weak and strong gel behavior as function of grafted macromolecules weight.