Abstract
We report the exfoliation of graphite in aqueous solutions under high shear rate [∼ 108 s–1] turbulent flow conditions, with a 100% exfoliation yield. The material is stabilized without centrifugation at concentrations up to 100 g/L using carboxymethylcellulose sodium salt to formulate conductive printable inks. The sheet resistance of blade coated films is below ∼2Ω/□. This is a simple and scalable production route for conductive inks for large-area printing in flexible electronics.
Highlights
We report the exfoliation of graphite in aqueous solutions under high shear rate [∼ 108 s−1] turbulent flow conditions, with a 100% exfoliation yield
The low Yw ∼ 1−2%40,45 for few layer graphene (FLG) prepared by bath sonication is due to the fact that a significant amount of graphite remains unexfoliated, as the ultrasonic intensity is not uniformly applied[46,47] and depends on the design and location of the ultrasonic transducers.[47]
The flakes are used in conjunction with sodium deoxycholate (SDC) (Aldrich)
Summary
We report the exfoliation of graphite in aqueous solutions under high shear rate [∼ 108 s−1] turbulent flow conditions, with a 100% exfoliation yield. The rheological properties are investigated using a Discovery HR-1 rheometer (TA Instruments) in a parallel-plate (40 mm diameter) configuration.[99] We monitor the elastic modulus G′ [J/m3 = Pa], representing the energy density stored by the material under shear,[100] and the loss modulus G′′ [J/m3 = Pa],100 representing the energy density lost during a shear process due to friction and internal motions.[100] Flow curves are measured by increasing γfrom 1 to 1000 s−1 at a gap of 0.5 mm, because this γrange is applied during screen printing.[101] Figure 8a plots the steady-state μ of an ink containing 73 wt % flakes (70 cycles) as a function of γ.̇ CMC imparts a drop in μ under shear, from 570 mPa·s at 100 s−1 to 140 mPa·s at 1000 s−1.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
