Ultrasonic and dielectric spectroscopy of composites based on polymers and organic or inorganic nanoparticles

Abstract

During the last decades nanotechnology has reached a great importance in the research world. The branch of technology is operating in various fields of application as communications and medicine. The main reason behind the use of nanocomposites is the enhancement of various properties when compared to individual components. Produced nanomaterials can display unique properties which are supported by morphological evidence at nanometer scale. For this reason, it is very important to understand, how properties of nano- and microcomposites depend on the ratio and type of its constituents. Moreover, it is important to determine the reliability and durability of a material prior to the massive production on the market. Therefore, conducted repetitive experiments under various conditions (e.g. increased temperature) could contribute to understanding the interfaces between various fillers and the surrounding medium within a nanocomposite. Polymer based composites with embedded solid fillers can incorporate mechanical and electrical properties of its constituents. In comparison with classical inorganic piezoelectrics, piezoelectric polymers have a number of advantages.On the frequency scale, acoustic waves of frequencies near to 10 MHz are commonly used in diagnostic ultrasound techniques (10 MHz). Therefore, results of ultrasonic investigation of pure P(VDF-TrFE) and its composites with BPZT at 10 MHz are of peculiar importance. In this work ultrasonic anomalies, related to the ferroelectric phase transitions in the materials under investigation, are discussed. Results of dielectric and differential scanning calorimetry (DSC) investigations of these new P(VDF-TrFE)/BPZT composites are also presented