| In this paper, we mainly studied the dispersion of fluorographene in various organic solvents. Then presented a simple and convinient method to fabricate high-yield and good-quality fluorographene by supercritical carbon dioxide exfoliation. The product was nucleophilic etched and the hybrid fluorographene was prepared on the support membrane. The processing had no use for any polymeric or surfactant stabilizers, and the used alcohols were very easy to be removed. The great significance was that the successful formation of relatively pure fluorographene colloids enabled the use of conventional low-cost solution-phase processing techniques without decreased the properties of fluorographene.Fluorographene was prepared by sonication in different solvents and at different times, it was investigated by UV visible (UV-VIS) characterization and stability test to find an excellent solvent. The structure of fluorographene and its interaction with alcohol solvents was characterized by Tyndall effect, Fourier transform infrared spectroscopy (FT-IR) and viscosity measurement.Fluoride graphite powder was exfoliated by the intercalated carbon dioxide and glycol molecules during an abrupt depressurization step. The mechanism of the exfoliation was discussed through the experimental analysis. Here supercritical carbon dioxide acted as a penetrant and glycol acted as a "molecular wedge" to exfoliate fluoride graphite very well. The properties of fluorographene nanosheets were detected by transmission electron microscopy (TEM), AFM (Atomic Force Microscope), UV-VIS spectra, Raman spectroscopy and and X-ray diffraction (XRD) analysis. High yield and pure fluorographene nanosheets were obtained(32 wt%, four times higher than that of the sample treated only by the traditional method of sonication). Its simplicity, high productivity, low cost, and short processing time make this technique suitable for large-scale manufacturing of fluorographene nanosheets.Hybrid Iodo-fluorographene was prepared under sonication. It was then heated and refluxed in order to carry out the iodine reaction, the metastable state "bad points" (allyl fluoride) could be formed. These "bad points" on the surface of fluorographene was nucleophilic etched by different reagents. Structure and properties of the etched fluorographene were characterized by TEM, FT-IR, contact angle, XRD, XPS, Zeta potential and Thermo Gravimetric Analyzer (TGA). The etching ability of reagents was also be studied.The etched porous fluorographene was vacuum filtrated and dried and then loaded it on the commercial support membrane to prepare ultrathin molecular sieve membrane. Pore size and distribution of membrane surface were characterized by contact angle and Brunner-Emmet-Teller measurements (BET). The type of nitrogen adsorption-desorption curve could also be detected by BET. |
