The research objective of the award is to understand at a fundamental level the physical properties of dielectric nanoparticle/polymer matrix nanocomposites, through modeling and properties characterization, and by tuning the composition, morphology and size matching of the nanocomposite components, and further, by introducing metallic nanoparticles or carbon nanotubes. The goal is to enable synthetic methods to improve the dielectric performance of the nanocomposites, assisted by a theoretical model of the system and its components. The dielectric performance is based on several important factors including the dielectric constant, the dielectric strength (breakdown voltage), and the mechanical strength of the system. The project involves three research parts: (1) to develop a systematic self-assembly processing technique to synthesize multi-phase dielectric nanoparticle composites with consistent nanostructure and properties, (2) to characterize the nano/micro structures and properties of proposed dielectric nano-composites using various techniques (EFM, SPM, X-ray diffraction, Raman spectroscopy, etc.); and (3) to develop a systematic modeling tool based on nano/micromechanics theory, which can incorporate the effects of size and microstructure, and to study the dielectric, piezoelectric; and electro-mechanical coupling behaviors of the proposed multi-phase dielectric nanocomposites.
If successful, the benefits of the research will directly impact the ability to prepare high power electrostatic capacitors. Capacitors are the key device in controlling and storing electricity in a wide range electronics, and, in addition, have been hailed as a potentially transformative technology for the Smart Grid: high-power-density capacitors are a solution for storage and conversion of energy from intermittent renewable sources (e.g., wind and photovoltaic installations). The technology can also be adapted to address load leveling and power quality management for conventional power sources. New generations of capacitors with improved dielectric performance will enable circuit design of power management systems to improve energy efficiency in a wide variety of contexts, including household, industrial and commercial settings.
The nature of the project is to investigate the dielectric properties of nanoparticle/polymer matrix nanocomposites, through systematic synthesis, characterizations and modeling. The goal is to enable synthetic methods to improve the dielectric performance of the nanocomposites, assisted by a theoretical model of the system and its components. The outcomes include 1) Systematic self-assembly process technique based on solvothermal method has been developed to synthesize a series of nanocrystals such as barium titanate (BT), BST, bismuth doped BT with uniform nano size, structure and properties. The advantage of the developed self-assembly processing technique is low temperature operation. 2) BT/BST PFA nanocomposite thin films have been successfully processed and the dielectric constant of the system can be enhanced to 34 for frequency range up to 1MHz. 3) Systematic theoretical modeling has been established to study the frequency-dependent dielectric properties of the nanocomposites. The optimized structure and properties have been obtained based on the models. 4) A new class of complex compound BaMn3Ti4O14.25 (BMT-134) has been successfully synthesized using Low temperature chemical synthesis and deposition methods by introducing metallic ions manganese (Mn) into titanium oxide based frameworks. The new material is multiferroic with hollandite structure. BMT-134 possesses not only high dielectric constant in wide range of frequency but also ferroelectricity, antiferromagnetic phase transition (TN =120 K) with a weak ferromagnetic ordering at lower temperatures. It has high potential for developing new magnetoelectric materials. The project has been successfully accomplished to provide fundamental understanding the dielectric properties of nanocomposites by optimizing the individual constituents’ properties and designing the composite structure. This achievement may further provide the new ways to prepare high power electrostatic capacitors. Capacitors are the key device in controlling and storing electricity in a wide range electronics, and, in addition, have been hailed as a potentially transformative technology for the Smart Grid: high-power-density capacitors are a solution for storage and conversion of energy from intermittent renewable sources (e.g., wind and photovoltaic installations). The technology can also be adapted to address load leveling and power quality management for conventional power sources. New generations of capacitors with improved dielectric performance will enable circuit design of power management systems to improve energy efficiency in a wide variety of contexts, including household, industrial and commercial settings. This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
