Mechanically strong, flexible and thermally stable graphene oxide/nanocellulosic films with enhanced dielectric properties
By Beeran P. T., Yasir; Bobnar, Vid; Gorgieva, Selestina; Grohens, Yves; Finsgar, Matjaz; Thomas, Sabu; Kokol, Vanja
Published in RSC Adv
The Royal Society of Chemistry
2016
Abstract
Flexible and eco-friendly films, with enhanced dielectric properties and the potential for energy storage applications, have been fabricated from ammonia-functionalized graphene oxide (NGO) nanoplatelets and wood-based cellulose nanofibrils (CNF) vs. (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) pre-oxidized (carboxylated) CNFs (TCNF) by the solvent casting method. Various CNF-NGO (CNG) and TCNF-NGO (TCNG) composite films prepared with 0.5-3 wt% of NGO were analysed structurally by FTIR and XRD spectroscopy, and evaluated optically by UV-Vis spectroscopy. The morphological analysis using SEM showed good dispersibility of the NGO sheets in the randomly-distributed CNF, and the dense and parallel-oriented TCNF cellulose nanofibrils. Such a synergistic effect of both components contributed to ultra-strong and ultra-stiff composite films with good mechanical and thermal stability, although they were more brittle with a smoother surface and lower transmittance for the TCNF based films, due to the stronger physico-chemical interactions with NGO. The dielectric performance was verified with a higher (3 wt%) NGO loading capacity, which resulted in a dielectric constant of [similar]46 vs. [similar]52, and conductivity of [similar]2.07 [times] 10-4 S m-1 vs. 3.46 [times] 10-4 S m-1 for CNG vs. TCNG films, respectively, at a frequency of 1 MHz, showing greater enhancement than other reported studies. Cyclic voltammetry and electrochemical impedance studies reveal the energy storage ability and electrochemical performance of the composite films, under kinetic- and diffusion-controlled processes for the CNG, and under a kinetic-controlled process for the TCNG films.
Microsoft is Ending Support for Windows 7
Microsoft will discontinue support for Windows 7 on January 14, 2020 which means Gamry will also be discontinuing support for Windows 7. If you are upgrading to Windows 10, like many companies and institutions, you need to be running Version 7 of our s oftware . Please note that only USB and Ethernet-based instruments can run in Version 7. Eligible users can download the latest version of our software through our online Client Portal .
If you haven't already registered your instrument, you can do so through the Client Portal .
Please email Technical Support if you have any questions regarding this transition. Please be sure to include your instrument model and serial number when contacting us.