Aqueous Dispersion of Carbon Fibers and Expanded Graphite Stabilized from the Addition of Cellulose Nanocrystals to Produce Highly Conductive Cellulose Composites

Abstract

Conductive cellulose composites have received much attention as emerging materials due to their unique properties, such as biodegradability and flexibility. However, the achievable levels of conductivity of these cellulose composites are generally low due to the intrinsically nonconductive properties of cellulose. In this study, cellulose nanocrystals (CNC) were applied for preparation of a carbon fibers/expanded graphite (CF/EG) dispersion which was coated on cellulose paper to prepare highly conductive cellulose composites. Such composite materials were characterized based on transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) observation, FT-IR, XPS, and XRD and by determining the zeta potential, particle size, contact angle, and rheological behavior. It was found that the addition of CNC resulted in a significant improvement in the stability of the CF/EG dispersion. These results were explained by the following facts: (1) CNC improved the surface charge of the CF and EG due to the presence of negatively charged groups on the CNC surface, and (2) CNC increased the wettability of the CF and EG due to large availability of hydroxyl groups from CNC. The as-prepared CF/EG/CNC dispersion was then applied by coating cellulose paper surfaces, and the obtained papers presented superior conductivity and high flexibility.

Nanocellulose, a Versatile Green Platform: From Biosources to Materials and Their Applications

“…In another scheme, CNCs were used as a additive to help improve dispersion of carbon fibers with graphite in ordet o achieve ha conductivity 276 .…”

Bioinspired structure-robust cellulose nanocrystal films with enhanced water resistance, photothermal conversion ability, and fluorescence

“…Mechanism of the interaction between f-SA, RhB and CNC By comparison of the mechanical properties of f-CNC with other reported CNC based composites (Bardet et al 2015;Benito-González et al 2019;Enescu et al 2019;He et al 2018;Lizundia et al 2016;Wang et al 2020Wang et al , 2017 in Fig. 3b and Table S1, it can be seen that the addition of f-SA with 5 wt% loadings to the neat CNC film simultaneously increase 2.09 and 2.13 times in tensile strength and modulus, respectively.…”

“…Generally, CNCs are isolated from cellulose by a controlled hydrolysis using sulfuric acid and they maintained stable suspensions in aqueous media (Nan et al 2017). Through controlling arrangement of nanocellulose into hierarchical structure, a series of transparent nanopapers (Huang et al 2013), nanocomposites (Liu et al 2018), and fibers (Shen et al 2015;Zhang et al 2019) could be constructed with outstanding mechanical and functional properties. Among them, CNC-based films have gained tremendous interest because of superior mechanical properties, low coefficient of thermal expansion, excellent optical transmittances, and favorable biodegradable ability, revealing great applications in food packing, optical sensor and structural materials fields (Benito-González et al 2019).…”

Printed electronics based on inorganic conductive nanomaterials and their applications in intelligent food packaging

“…Osikoya et al fabricated a CVD graphene sheet grown from acetylene as the carbon source, with a large available surface area, while the sheet resistance was as low as 125 U sq À1 . [78][79][80] However, the biggest challenges for this technique are the high cost and complex processes involved.…”