Javier Martínez, Amarilis Declet, Nelson Sepúlveda, O. Marcelo Suárez

Department of Mechanical Engineering

University of Puerto Rico - Mayagüez

8th NEA Science Day – March 19, 2015

Northeast Alliance for Graduate Education and the Professoriate

Liaison Office University of Puerto Rico– Mayagüez

Recently bio-ferroelectric composites have triggered intense interest as a sustainable alternative for processable high permittivity materials and other electronicapplications such as capacitors, transistors, and actuators. In particular, the biopolymeric matrix improves the necessary flexibility of the composite. The presentresearch involves the development of a bio-ferroelectric composite using a chitosan-cellulose matrix and ferroelectric nanoparticles with high dielectric constant. Theferroelectric nanoparticles were added to the polymer solution and the solution was further homogenized to improve the nanoparticles dispersion. The composite wasstructurally and mechanically characterized. Dielectric constant measures have also been made to further characterize the composite. Cellulose concentrations werevaried to test the hypothesis that for a higher percentage of cellulose in the composite, the mechanical tensile properties of the composite would be enhanced. Thedata showed that for higher concentrations of cellulose, the composite lost mechanical strength. Also, the dielectric constant value seems to decrease for a higherconcentrations of ferroelectric particles.

INTRODUCTION

Higher dielectric constant

Technological applications

Ferroelectric behavior

Abundant bio-polymers

Biodegradable

Biocompatible features

Strontium Titanate

NanoparticlesChitosan and

Cellulose

OBJECTIVES

The first objective was to study mechanical properties of

chitosan when different concentrations of cellulose are

added to the solution.

The second objective was to analyze the effects of

ferroelectric nanoparticles (SrTiO3) on the chitosan-

celullose composite electrical properties.

Scanning Electron Microscopy

ANALYSIS OF RESULTS

X-Ray Diffraction Analysis

Tensile Analysis

Dielectric Properties

CONCLUSIONSHigher amounts of nanoparticles lowered the ultimate tensile strength of the composites.

Additionally, higher concentrations of nanoparticles raise the capacitance, dielectric

constant and resistivity of the material.

REFERENCESJ. Hosokawa et al., “Reaction between chitosan and cellulose on biodegradable

composite film formation,” Ind. Eng. Chem. Res., vol. 30, no. 4, pp. 788–792, Apr. 1991.

P. Barber et al., “Polymer Composite and Nanocomposite Dielectric Materials for Pulse

Power Energy Storage”, Materials, pp. 1-37, Oct. 2009.

This material is based upon work supported by NSF under Grants No. 0833112 &

1345156 (CREST program). We wish to thank the Power Electronic Laboratory of UPRM.

ACKNOWLEDGEMENTS

Chitosan and cellulose

solutions

Small Solution

Drying Process

METHODOLOGY

Chitosan and cellulose

solutions

Small solutions with

SrTiO3 nanoparticles

Assembly for Dielectric

Measurements

Schematic for Dielectric

Measurements

Low Magnification High Magnification