Preparation And Properties Of Nano-carbon Materials

Carbon nanotubes (CNTs) and graphene are sp2 hybridized carbon nanostructures which will make possible new applications in many fields duo to their extraordinary physical and chemical properties. In this thesis, resilience and oil adsorption properties of carbon materials were investigated using two kinds of CNTs:super resilience of agglomerated carbon nanotubes (ACNTs) and vertically aligned carbon nanotubes (VACNTs). After that, we demonstrated a green and facile approach to the synthesis of graphene nanosheets by reduction of graphite oxide, and investigated the adsorption properties of RGO. Finally, graphene nanosheets (GNS)/alumina composites were prepared by SPS, and the properties of the composite were also studied. The detail results are summarized as follows:We combined ACNTs and NG to form a spring-shim structure in which ACNTs acts as the "spring" that facilitates configurationally recovery, and NG acts as the "shim" that transfers the force and prevents ACNT entanglement and subsequent mechanical seizure. The mechanical performance of a compressed mixture of NG and ACNTs was examined over the pressure range of 30～300 MPa. NG-ACNTs composite materials showed improved performance over the ACNT materials alone. Nanocomposites containing 5% NG mixed with ACNTs had an expansion ratio of 2.7 and illustrated a lower loss of resilience.We used CNTs as oil adsorbents and evaluated recycling performance by squeezing method. The sorption capacity of 3 mm long VCNTs is almost 6.9 times higher than that of ACNTs due to the existence of large-sized macropores. Compared with EG (41 g/g), VCNTs exhibit higher sorption capacity (69 g/g) and better recycling performance due to their unique mechanical strength and excellent rebound resilience properties at high strains.The synthesis of graphene nanosheets from graphite oxide typically involves harmful chemical reductants that are undesirable for most practical applications of graphene. Here, we demonstrate a green and facile approach to the synthesis of graphene nanosheets based on Al or Fe reduction of exfoliated graphite oxide, resulting in a substantial removal of oxygen functionalities of the graphite oxide.The pseudo-second-order model described the adsorption kinetics well. The adsorption equilibrium data fit Langmuir isotherm equation well with a maximum MB adsorption capacity of 111.62 mg/g, as well as easy magnetic separation from the solution. Graphene nanosheet/alumina composite was prepared by spark plasma sintering. A homogeneous distribution of nanosheets in an alumina matrix could be obtained by the electrostatic attraction between graphite oxide and alumina particles and their subsequent reduction. The introduction of graphene nanosheet leads to refinement of grain size of alumina after hot pressing. The experimental results have shown that the fracture toughness and conductivity of the graphene nanosheet/alumina composite are about 53% and 13 orders of magnitude higher than those of unreinforced alumina material, respectively.