| Currently, plasma technologies are widely applied in nanoscience, in which, the nanostructures are formed by assembling or etching through electrons, atoms, ions, excited molecules generated in plasma. It is considered to be a feasible and effective method with low-cost for forming crystal nanostructures through transition processes of gas-solid or gas-liquid-solid. Although synthesis of inorganic metallic nanocrystals by plasma enhanced chemical vapor deposition (PECVD) is well reported, less has been done on preparation of organic nanocrystals by PECVD.In this paper, a new atmospheric plasma polymerization method of forming fluorocarbon naonocrystal by cylinder reactor DBD (dielectric barrier discharges) is developed. It provides a new way to form polymer nanostructures. The content in the paper are organized as following:Firstly, the discharge characteristics of cylinder reactor dielectric barrier discharge are measured and simulated to obtain the discharge parameters for fluorocarbon plasma polymerization. The measured discharge voltage and current waveforms suggest that this DBD is formed by filament discharges. The electron excitation temperature is in the range of 0.24 eV to 0.32 eV, measured by optical emission spectrum from argon plasma. The consumption power of discharge is 0.28～1.13kW, estimated by the charge-voltage method, which was measured by an oscilloscope. The numerical simulation on coaxial cylinder reactor dielectric barrier discharge at atmospheric pressure is carried out using the method of particle in cell (PIC). The obtained results illustrate the process of microdischarge forming and evolution, in which the life-span of microdischarge is shown to be about 4 ns. Also the spatial-temporal distribution of electronics density, ion density, barrier surface charge density and electric-field are given. It shows that electron, ion, barrier surface charge are all accumulated in the regime of anode above dielectric surface.Secondly, the surface morphology and the size distribution of crystalline nanoparticles are investigated by scanning electron microscope (SEM). The average diameter for the nanorods formed on the film deposited on glass slide is about 100nm and the length is between 1 urn and 2.5 urn, nanoparticles with an average size of 150 nm are formed through introducing plasma active particles into the ethanol, These nanoparticles are well dispersed when the ethanol is dropped on glass.Finally, the chemical composition and structure of fluorocarbon polymers are analyzed by X-ray photoelectron spectroscopy (XPS) and fourier transform infrared spectrum (FTIR). There are some oxygen and hydrogen besides a lot of fluorine and carbon, and the fluorine to carbon ratio decreases with discharge power increasing. The typical peaks of the polytetrafluoroethylene are found in this film by analyzing the results of the FTIR. On the results of transmission electron microscopy (TEM), high-resolution transmission electron microscopy(HRTEM), selected area electron diffraction(SAED) and X-ray diffraction (XRD), the nanoparticles and nanorods are characterized to be polycrystalline and single crystalline with hexagonal and cubic structure, respectively.In a word, an easy, effective and low-cost method for forming organic crystal nanostructures by atmospheric pressure DBD plasma polymerization is developed. This novel polymerization process can be applied to systhesis other crystal polymers. Properties of these fluorocarbon nanocrystals need to be further investigated before getting actual application in nanofabrication.
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