Facile and fast combustion synthesis and characterization of novel carbon nanostructures

Abstract

We present the exploratory results on fast combustion synthesis (CS) of carbon-related nanomaterials including the exfoliated graphite. We found earlier that different solid compositions containing strong reducers and carbon-bearing oxidizers could yield carbon vapors that may instantly condense toward 1D and 2D nanocarbons. Here, such a combustion route is extended toward the processing of the mixtures of a strong reducer (Mg, Si, AlH 3 , CaH 2 , or BH 3 NH 3 ) and a strong oxidizer (C 2.78 F 2 , TEFLON 1 PTFE (CF 2 ) n or PVC (C 2 H 3 Cl) n ) in a heterogeneous, efficient, autothermic, high-pressure, and high-temperature reaction. The combustions were carried out both under neutral (Ar) and active atmosphere (CO 2 ) at the starting pressure equal to 10 atm. The solid products (layered graphite and nanocarbides) were chemically purified and characterized using XRD, SEM, TEM, and Raman spectroscopy.Combustion synthesis reaction chambers.

A review of exfoliated graphite

“…Because of this preferred orientation and the cellular structure of the worms, the sheet is resilient in the direction perpendicular to the sheet. This resiliency is valuable for flexible graphite to function as (i) a gasket material for fluids (including fluids in harsh chemical or thermal environments, as relevant to asbestos replacement) [27], (ii) an EMI gasket material (the EMI shielding effectiveness as high as 130 dB at 1 GHz [52][53][54][55]), (iii) a thermal interface material (abbreviated TIM, due to the enhanced conformability provided by the resiliency and the need for the TIM to conform to the surface topography of the sandwiching surfaces) [58], and (iv) a vibration damping material (due to the viscous behavior of the sheet, as discussed in ''Viscous and elastomeric behavior'' section) [52].…”

“…In order to increase this force, so that the degree of expansion is relatively high, the heating rate should be high. The rapid heating can be conducted using furnace heating [24], microwave heating [24][25][26], or combustion [27].…”

Graphene‐Like Carbon Nanostructures From Combustion Synthesis

“…We showed earlier that SiC nanowires can be easily and autothermally formed in the Si/PTFE system. [8] Carbon nanomaterials, including graphene-related ones, were obtained via Mg and Si reduction of appropriate oxidants: CO x , [9] C x N y H z , [10] GO and CF x , [11,12] C 2 H 2 O 4 , [13] MgC 2 O 4 , and CaC 2 O 4 . [14,15] Natural carbon-bearing minerals (dolomite, limestone, siderite) can also be CS processed.…”

“…The combustion was carried out in a stainless-steel highpressure reactor (volume 375 cm 3 ) following the protocol outlined elsewhere. [11] A green (biocompatible) stoichiometric mixture of reactants (Mg/standard CaCO 3 ) was homogenized in a ceramic mortar and placed into the reactor under pre-defined atmosphere and pressure (Ar, 0.1-1 MPa). The combustion was initiated by means of an electrically heated carbon thread.…”