High-yield production of graphene flakes using a novel electrochemical/mechanical hybrid exfoliation

Sulfonated graphene oxide/sulfonated poly (2,6‐ dimethyl – 1,4‐phenylene oxide) as a potential proton exchange membrane for iron air flow battery application

“…In Figure 5B, the peaks at 1597 and 2424 cm À1 are assigned to the G-band and 2D-band, respectively, with an intensity ratio I 2D /I G (area) of 1.8, indicating a bilayer or single-layer graphite, which also has a small lateral size and low crystallinity with high electronic conductivity. 42,43 Raman analysis of GO revealed a strong peak at 1356 and 1592 cm À1 corresponding to the D and G bands. The G band is attributed to the sp 2 carboncarbon bond, and the D band originates from the activated first order scattering of sp 3 carbons in the GO layers.…”

“…44 The D/G area intensity ratio (I D /I G ) and the 2D/G intensity ratio (I 2D /I G ) were used as an index to determine the graphene defects and quantify the number of stacked graphene layers, respectively. [42][43][44][45] The SGO intensity of the "G band" at 1587 cm À1 increased and shifted toward the D band at 1351 cm À1 , decreasing the disorder to defect ratio (D/G) from 1.39 (GO) to 0.88 (SGO), indicating the successful sulfonation of GO. This is consistent with the reduced structural disorder resulting from the reappearance of a 2D band at 2415 cm À1 and the improved electron conductivity of the graphene structure with an I 2D /I G ratio of 0.41, indicating a multilayer SGO.…”

Superior quality chemically reduced graphene oxide for high performance EMI shielding materials

“…These techniques enhance the RGO conductive properties and provide diverse RGO qualities with uncommon results for the same application. [13][14][15] This work focuses on the chemical and thermal reduction protocols with a high yield and scalability advantage including the ability to ne-tune the amount of oxygen by regulating the experiment conditions during the oxidation and reduction process. 16,17 The chemical reduction techniques are commonly used for RGO production by applying several reducing agents, such as hydrazine, 18 sodium borohydride, 19,20 L-ascorbic acid.…”

An ecologically friendly process for graphene exfoliation based on the “hydrodynamic cavitation on a chip” concept

“…In general, in top-down methods, the process involves mechanical and chemical energies to break down weak van der Waal forces in high-purity graphite sheets. 27,28 Typically, the mechanical routes for exfoliation of flakes apply in the form of two forces. The vertical impacts act on the flakes, which causes to overcome energy between layers to peel them apart (normal force), and the sliding relative movements between layers occur due to the exerted lateral force (shear force).…”