Design of New Piezoelectric Composites Using Nanocellulose
Technical Report,01 Dec 2015,31 May 2019
PENNSYLVANIA STATE UNIVERSITY UNIVERSITY PARK United States
Pagination or Media Count:
This research project focused on cellulose crystals as building blocks for the design and development of new low-density functional polymer composites. Although the piezoelectricity of cellulose has been predicted from its noncentrosymmetric crystal structure, it has not been measured accurately nor has cellulose been properly exploited as a piezoelectric material. If it is proven, it could enable novel low-density electroactive materials capable of surpassing the performance of the best synthetic piezoelectric polymer such as polyvinylidene difluoride PVDF. To fulfill this objective, a systematic study was required to judiciously manipulate dipoles of individual cellulose nanocrystals to produce polar ordering at the macroscale. With the unique capability of spectroscopically determining the degree of polar ordering of cellulose in the sample using vibrational sum frequency generation SFG spectroscopy, we found that none of the previously used methods for preparation of cellulose-containing piezoelectric materials really produces any polar ordering. Thus, what was reported as a piezoelectric response of cellulose in the literature cannot be attributed to piezoelectricity we found that what was reported falls under electromechanical coupling originating from other extrinsic mechanisms.
- Laminates and Composite Materials