Study On The Sol-Gel Preparation And Characteristic Of C₆0/Polymer Composite Films

C60 is a new allotrope of carbon. Since its discovery by Kroto team in 1985, the unusual chemical and physical characteristics of this new material have generated great interest in many fields of science, and people also think that C60 has many potential applications that have wide prospects for scientific and technological purposes.In this thesis, a systemic study on C60IPMMA composite films was undertaken. By using sol-gel method, C60/PMMA films with different C60 contents both on Si(lOO) and quartz substrate were successfully prepared. Analysis of FTIR spectra showed that C~ was distributed equally among PMMA, and the structure of C60 molecule was not destroyed. X-ray diffraction results suggested C60 molecules in PMMA tend to aggregate each other and to form some tiny crystallized clusters. It was observed that the size of these clusters enlarged dramatically with the increase of C60 content in C6OIPMMA films. In case of being annealed under vacuum at high temperature close to the melt point of PMMA, it was found that the C60 clusters have the tendency to grow with (111) preference orientation of FCC structure. Some TEM measurements were also given to confirm the structure of the films. Combined XRD and TEM results, a possible mechanism of the film formation was proposed.In recent years, the investigation for charge-transfer complexes has gained considerable interest. From the view of theory, C60/PMMA complex system has been proved to own some great charge transfer properties. In this paper, we reported our Raman spectrum and UV-Vis results to demonstrate the charge transfer phenomenon that took place in C60IPMMA films. It was observed that the Ag(2) pentagonal pinch mode of C60 at 1469cm?shifts to a lower frequency of 1455cm?from Raman scattering measurement at room temperature. To our knowledge, this is the first time to find such red-shift phenomenon correlated with the charge transfer between the two phases in C6dPMMA films. Moreover, the phonon softening was compared with a theoretical calculation performed in graphite intercalation compounds (GIC). The charge transfer effect was also evidenced with UV-Vis observations.In this work, the author has partly participated in the study on preparing C60 films by a physical deposition technique named Hot-Wall Epitaxy method. Several factors that influence the quality of C60 films were discussed by X-ray diffraction measurements, and a (111) oriented C60 film was grown successfully on surface-treated silicon substrate. XRD results showed that the temperature of substrate had little impact to the oriented growth of C60 films although it strongly influenced the quality of them; It was found that C60 films tended to grow more easily than they were prepared under lower one. Moreover, the substrate with weak surface dangling bands was found to be necessary for the oriented growth of C60 films.