Photoemission studies of fluorine functionalized porous graphitic carbon

Abstract

Articles you may be interested inPhysically and chemically stable ionic liquid-infused textured surfaces showing excellent dynamic omniphobicity APL Mat. 2, 056108 (2014); 10.1063/1.4876636 Thermal grafting of fluorinated molecular monolayers on doped amorphous silicon surfacesPorous graphitic carbon (PGC) has unique properties desirable for liquid chromatography applications when used as a stationary phase. The polar retention effect on graphite (PREG) allows efficient separation of polar and non-polar solutes. Perfluorinated hydrocarbons however lack polarizabilty and display strong lipo-and hydrophobicity, hence common lipophilic and hydrophilic analytes have low partition coefficiency in fluorinated stationary phases. Attractive interaction between fluorinated stationary phase and fluorinated analytes results in strong retention compared to non-fluorinated analytes. In order to change the selectivities of PGC, it is necessary to develop a bonded PGC stationary phase. In this study, we have synthesized perfluorinated, PGC using hepatadecafluoro-1-iodooctane, under different temperature conditions. Surface functionalization of the raw material was studied using photoelectron spectroscopy (PES). Results indicate the existence of fluorine containing functional groups, ÀCF, ÀCF 2 along with an intercalated electron donor species. Multiple oxygen functional groups were also observed, likely due to the presence of oxygen in the starting material. These oxygen species may be responsible for significant modifications to planer and tetrahedral carbon ratios.

Multi‐instrument characterization of the surfaces and materials in microfabricated, carbon nanotube‐templated thin layer chromatography plates. An analogy to ‘The Blind Men and the Elephant’

“…While negative ion SIMS of CNTs has been reported, there does not appear to have been any recognition or discussion of this effect, although odd–even effects of secondary ions from other carbon‐containing materials are known The valence band spectrum of CNTs taken with X‐radiation (Al Kα) does not appear to have been reported.As has previously been reported for highly ordered pyrolytic graphite and CNTs, the C 1 s peak is asymmetric . We similarly observe this asymmetry, which can be confused with oxidized carbon moieties.…”

“…291 eV is the π → π * transition or shake‐up peak. Both of these features are common in graphitic carbon and CNTs . The valence band (VB) region consists of a signal that increases steadily with increasing binding energy to ca.…”

Reduced graphene oxide-NH2 modified low pressure nanofiltration composite hollow fiber membranes with improved water flux and antifouling capabilities

“…Curve fitting of C 1s spectra was analyzed by using the XPS Peak 4.1 program. The XPS spectra were using Shirley-type background to subtract, and the Gaussian-Lorentzian peak shape were used after performing background and with a similar FWHM (full-width halfmaximum) for all C1s peaks [34,35].…”

One-Step In Situ Patternable Reduction of a Ag–rGO Hybrid Using Temporally Shaped Femtosecond Pulses

“…To verify that silver oxide was not contained in the hybrid, binding energy (BE) values of 367.4 eV (AgO) [41], 367.7 eV (Ag 2 O) [42], and 368.3 eV (Ag) [43] were considered when fitting the Ag 3d spectra; no Ag(I) or Ag(II) states were found (Figure 3e), demonstrating the existence of the metallic form of silver. As to the fitting of the C 1 s spectra, different carbon forms such as C sp 2 as the nonfunctionalized planar carbon, C sp 3 as the aliphatic nonfunctionalized tetrahedral carbon [44], and oxygen groups such as hydroxyls, carbonyls, and carboxyls should be considered. Moreover, studies have reported that the BE separation values of C sp 3 and other oxygen groups with respect to C sp 2 were 0.7 eV (reduced graphene oxide) [40], 1.2-2.5 eV (C-OH), 2.1-3.5 eV (C=O), and 4.0-5.4 eV (C-OOH) [45], respectively.…”