Preparation Of Oxidized Graphene Nanosheets And Its Application In Carbon Fiber Dispersion

Graphene, a one-atom thick, two-dimensional carbon nanomaterial, has attracted more and more attention due to its outstanding electrical, optical, thermal and mechanical properties. Graphene oxide (GO), as the intermediate material of the redox process for graphen, can be viewed as an unconventional soft material due to the unique chemical structure.GO possesses unique amphipathy for the present of hydrophilic groups on the edges and hydrophobic in the basal plane. The unique chemical structure also endows GO with outstanding biocompatibility. So GO shows great promise in the area of biological sensors, drug carrier, biological imaging and surface active agent. These features would be more prominent for GO nanosheets (GONSs) with lateral diameter smaller than 100 nm.Currently, GONSs was prepared from graphite nanofibers or graphite nanopowders, or with a complicated process of preparation and separation. All of these methods are low yield, high cost and complicated. So it is an important research direction in the field of graphene to explore a procee for large scale preparation of GONSs with common graphite. The one of the unique properties of GONSs is a good dispersing agent for virious carbon materials, so GONSs could be used for preparation of all carbon composite materials.Here, ultrasonication assisted Hummers’method was introduce to prepare GONSs with lateral size smaller than 100 nm. We studied the effect of ultrasonication on the structure and oxidation degree of GO. Furthermore, a high power ultrasonicaiont with cavitation effect was used to obtain GONSs with an average lateral size of 50 nm. And another more effective process, microwave assisted-ultrasonication process, was introduce, and GONSs with lateral size of about 30 nm was prepared with the yield of 65%. The mechanism of the oxidation etaching was discussed under microwave irradiation.Single walled carbon nanotubes (SWCCNTs) was dispersed with GONSs as surfactant. UV-vis spectrophotometer was introduce to analysis the stability of the dispersion before and after centrifugation, and then we found that the dispersion possess very good stability. Then transparent conducting film was prepared by spray coating method on the PET, and further post-treatments, such as reduction and acid washing were introduced to the films. Then ScotchTM tape was used to test the film adhesion. We foud the adhension of the films on the PET was improved compared other studies, and the mechanism was further studied, and analysis the effect of the various post-treatment.