The ways of use of multilayered graphene in engineering ecology.

The applications of multilayered graphenes (MLGs), nanocomposites "MLG-decontaminant" and polydicarbonfluoride intercalation compounds for the localization and deactivation of toxic spills and gaseous emissions under technogenic accidents are investigated in this paper. The intercalation compounds contain oxidizers as intercalants, and MLGs are formed destructively by thermolysis of polydicarbonfluoride intercalation compounds. The sorptive capacity of MLGs (about 240 ml of liquid phase per 1 g of MLG) is much higher than in well-known expanded graphites (EGs) obtained from graphite oxide or graphite acid salts. Our investigation revealed the possibility of the production of the "MLG-decontaminant" nanocomposites with the neutralizator content >95% due to the extremely low (down to 0.4 g/l) apparent density of MLG and its high specific surface (about 370 m2/g). The use of these nanocomposites for the acid-base or redox neutralization of contaminants does not result in the overheating, sputtering or evaporation of liquid phases, because their neutralization products sorb into MLGs. It prevents the soil mineralization by liquid or solid deactivated spills. We revealed that polydicarbonfluoride intercalation compounds with oxidizers (ClF3, HNO3, N2O4) can be efficiently used for the deactivation of spills and gaseous emissions of nitrogen-containing base compounds.

The Influence of Dimensional Effects on the Composition and Properties of Polydicarbonfluoride.

The influence of dimensional effects on the compositions and properties of polydicarbonfluoride (C2 F)n prepared from multilayered graphenes was investigated. Multilayered graphenes were produced by destructive thermal decomposition of intercalation compounds of "idealized" (C2 F)n that were obtained by reaction of gaseous ClF3 with natural graphite at a room temperature. The precursors of multilayered graphenes have a common formula (C2 F⋅xR)n where R is an organic or inorganic component. It was shown that polydicarbonfluoride prepared from multilayered graphene does not form stable intercalation compound with ClF3 , in contrast to polydicarbonfluoride prepared from graphite, that forms its intercalation compound with ClF3 during fluorination of initial graphite in the ClF3 excess. Investigations of polydicarbonfluoride prepared from multilayered graphene showed that it cannot form intercalation compounds with different classes of organic and inorganic compounds as polydicarbonfluoride prepared from graphite can do. The absence of such intercalation activity for polydicarbonfluoride prepared from multilayered graphene can be explained by high exfoliation degree of multilayered graphene (3-4 nm) along the c-axis that results in the presence of two-dimensional (2D) structure properties in multilayered graphene. Dimensional effects transformed the chemical properties of polydicarbonfluoride prepared from multilayered graphene and lowered its decomposition temperature by 150 K in comparison with polydicarbonfluoride prepared from graphite.

One-step exfoliation synthesis of easily soluble graphite and transparent conducting graphene sheets.

Easily soluble expanded graphite is synthesized in a one-step exfoliation process that can be used for the lowcost mass production of graphene for various applications because of the simplicity and speed of the process. The graphene obtained is sufficiently expanded to be dispersed in aqueous solutions with an ordinary surfactant and in organic solvents.