Fabrication and characterization of bioferroelectric composites
AdvisorSuárez, O. Marcelo
CollegeCollege of Engineering
DepartmentDepartment of Mechanical Engineering
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Bio-ferroelectric composites have recently sparked intensive research in order to develop inexpensive and environmental electronic devices such as capacitors, transistors, and actuators. The present research involves the synthesis of composites made of a chitosancellulose polymeric layer and ferroelectric nanoparticles. To fabricate the bio-ferroelectric composites, a chitosan/cellulose layer was synthesized followed by a layer containing ferroelectric nanoparticles. The variables considered includes the volume percentage of cellulose (15v% and 25v%) in the matrix and the amount of ferroelectric nanoparticles (10wt% and 20wt%). Additionally, the acetic acid concentration upon synthesis was studied due to its effects on the swelling degree of the composites. The composites underwent tensile, thermogravimetric and thermomechanical tests. Furthermore, dielectric properties were measured; including capacitance, dielectric constant, current density, and electrical resistivity. In order to analyze their sustainability for electronic applications, the composites were degraded under different acid solutions. The results showed that higher percentages of cellulose decreased the ultimate tensile strength (UTS) and the degradation temperature Tdeg of the chitosan-cellulose composites while the addition of cellulose slightly raised the UTS and Tdeg of the chitosan-cellulose composites with strontium titanate nanoparticles. Conversely, our results demonstrated that the acidity of the solution decreased the mentioned mechanical and thermal properties. The most interesting part consisted in the study of the dielectric properties; capacitors with higher dielectric constants were fabricated. Additionally, our capacitors are able to withstand higher voltages; the dielectric breakdown of the bioferroelectric composites at 60V was not observed.