Natural graphite exfoliation

TEG macrostructure differs from that of natural graphite it possesses abnormally high porosity and highly developed active surface (40-50 m2/g) (Figure 1). The performed thermochemical treatment leads to an essential exfoliation of graphite matrix with a formation of cellular structure. The thickness of cell s walls is equal to 20-25 nm. The surface of cell s walls contains a lot of macrocracks, outcrops of crystallites, etc. The thermochemical re-treatment was applied to enhance TEG dispersivity. 

The average particle size values for NGZ (GAK-1 type) and NGF was determined to be, in particular, 35-40 pm. The specific surface area of such graphites in initial and final states is also practically identical and is of approximately 6.8-7.0 m2/g for natural graphite and approximately 20-25 m2/g for the internally produced exfoliated graphite. 

Carbon materials used for the commercial synthesis of carbon fluoride include natural graphite, petroleum coke, activated carbon, carbon black and carbon fiber. Experimental carbon materials include residual carbon, exfoliated graphite, fullerenes and other unique carbons and carbon inserts. The degree of graphitization of carbon material varies continuously, so it is not simple to define the exact boundary between carbon and graphite. The product formed... 

In the case of intercalation reactions, the nanotexture of the host carbon materials has a strong effect. The intercalation of sulfuric acid into natural graphite can proceed at room temperature in concentrated sulfuric acid with a small amount of oxidant, such as nitric acid. The resulting intercalation compound is commonly used in industry for the preparation of exfoliated graphite [32], However, in order to intercalate sulfuric acid into carbon fibers, electrolysis is needed [145,146], Potassium as a vapor, on the other hand, can be easily intercalated in various carbon materials, even in low-temperature-treated carbon fibers [147],... 

Any kind of carbon, such as natural graphite, petroleum coke, carbon black, carbon fiber, exfoliated graphite, natural or synthetic graphite and fullerenes can be fluorinated under controlled conditions. Each carbon has unique crystalline properties. To achieve a desired degree of fluorination — or carbon fluorine ratio — numerous experiments are conducted in specialized TGFA reactors to determine the operating conditions such as fluorination temperature, fluorine flow rate, and fluorination duration. 

---