Pulsed additions of F₂ gas and monitoring of the fluorination temperature.

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... fluorine was added in a closed reactor starting from primary vacuum (10 3 mbar). 5 g of graphite were located onto 2 plateaux. Before the reaction, moisture and oxygen were removed by applying a primary vacuumm (10 3 mbar) at Fig. 1. Structures of graphite, poly(dicarbon monofluoride) (C 2 F) n and poly (carbon monofluoride) (CF) n . 200 • C. Fig. 2 displays the process with pulsed addition of F 2 ...

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... order to determine the fluorination temperature, the fluorine pressure was recorded as a function of the time and temperature (Fig. 2). As discussed in the introduction part, the reactive gas was added at 200 • C, a temperature at which no reaction occurs. The first temperature step was 270 • C without reaction. At 360 • C, F 2 was slightly consummed in accordance with Kita's "(C 2 F) n rich" region, i.e. 350-400 • C. The fluorine pressure droped at 430 • C sign of a ...

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... the percentage of (C 2 F) n structural type. 76 % of C-F bonds are included in the (C 2 F) n structural type (24 % in (CF) n ). Moreover, the F/C ratio can be extracted from the fits thanks to formula F/C --S C-F /(S C -F + S C-C-F ), where it remains constant around 0.50-0.60 regardless of the fluorination and annealing temperatures (see Fig. SI2a and Table SI1 in supplementary information) and in good agrement with the weigth uptake method. The %(C 2 F) n is 70 %, 72 % and 67 % for F520-KS, F550-KS and F610-KS, respectively. The higher the annealing temperature, the higher the content of (CF) n type. The shorter fluorination duration for F520-KS 18 h explains the slightly ...

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... case of 19 F spectra is more complex since 5 lines are recorded in addition to the minor ones of CF 2 ( 120 ppm) and CF 3 ( 80 ppm) instead of one expected (Fig. 3b) [57,58,61,62]. Differences appear according to the fluorination and annealing temperatures (Fig. SI2b). When those temperatures increase, the integrated surfaces of the lines at 160 and 168 ppm decrease. Those lines are assigned to 19 F in C-F bonds in (C 2 F) n and (CF) n types with non-fluorinated sp 2 carbon in their neighboring, denoted (C 2 F)(Csp [2]) and (CF)(Csp [2]) for lines at 160 and 168 ppm, respectively. 13 C data (Fig. ...

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... This assignement is in perfect aggreement with the chemical shift at 178 ppm of fluorinated nanodiamonds, i.e. Csp [3]-CF (the 13 C chemical shift is 42 ppm) [15]. Fig. 3b summerizes the above assigments with the notation (C 2 F)(Csp [2]), (CF)(Csp [2]), (C 2 F)(C 2 F), (C 2 F)(CF) and (CF) (CF). The content of (C 2 F)(C 2 F) is nearly constant (Fig. SI2b) and increasing the fluorination and annealing temperatures increase the contents of (C 2 F)(CF) and ...

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... both FT F -KS and FT F -NG series (T F is the fluorination temperature), the increase of the annealing temperation does not increase the content of (C 2 F) n phase, i.e. around 72 and 95 % for FT F -KS and FT F -NG series, respectively (Fig. SI2 and SI3 and Table SI1). On the contrary, when the annealing temperature is increased to 610 • C, the content of (C 2 F) n phase decreases down to 67 % in both series. In that case, the percentage of (C 2 F) n region converted to (CF) n increased, probably close to the material ...

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... equal to λ Bragg(F450KS KS) n = 2 • 9.1 ˚ A ∼ 18.2 ˚ A. Direct measurements of scattering cross sections for wavelengths λ n > 9 ˚ A require further improvement of the diffractometer. The range of neutron wavelengths and velocities for which poly(dicarbon monofluoride) (C 2 F) n provides high efficiency of neutron reflection is shown in Fig. 12. 3 and 0.337 g/ cm 3 , respectively. The red dashed line shows the expected scattering cross section for F450-KS with the density of 2.6 g/cm 3 (the maximum achieved value after decompression, see Figure SI8). As clear from the comparison of solid red and dashed red curves, the density of F450-KS can strongly change as a function of ...