Discipline: Technology and Engineering
Subcategory: Materials Science
Nelson E. Sepúlveda-Ramos - University of Puerto Rico – Mayaguez
Co-Author(s): Amarilis Declet, Javier Martinez, and Oscar Marcelo Suarez, University of Puerto Rico-Mayaguez, Mayaguez, PR
Scientists have focused on studying bio-ferroelectric composites to develop new environmentally friendly and inexpensive electronic elements such as capacitors, actuators and transistors. In the present research, bio-ferroelectric nanocomposites were prepared with a matrix composed of chitosan-cellulose, which was reinforced with strontium titanate (STO) nanoparticles. In this study some of the composite characteristics evaluated were the effect of the cellulose concentration in the matrix at different amounts of STO nanoparticles. To fabricate the bio-ferroelectric composites, a chitosan-cellulose layer was synthesized followed by a layer containing the ferroelectric nanoparticles. These composites underwent electrical tests to determine their dielectric constant, current density and conductivity. The results revealed that the addition of nanoparticles raised the dielectric constant and lowered the current density and the conductivity of the bioferroelectric nanocomposites. The highest value of the dielectric constant obtained was 505.83 for the composite containing 15 v% cellulose and 20 wt% at 1 KHz frequency. The dielectric strength test, using a “step by step” method, was performed by varying the voltage from zero to 60 V. At this value the samples have not reached their breakdown voltage. It is believed that this biopolymer-based composites reinforced with STO ferroelectric nanoparticles have promising characteristics suitable for radio frequency and microwave applications in which high electrical tunability and flexible dielectric waveguide are required.
Funder Acknowledgement(s): This material is based upon work supported by the National Science Foundation under Grant No. 1345156 (CREST program).
Faculty Advisor: Oscar Marcelo Suarez, msuarez@ece.uprm.edu