Microwave synthesis of ultrathin, non-agglomerated CuO nanosheets and their evaluation as nanofillers for polymer nanocomposites

In this work, ultrathin, non agglomerated and defect free CuO nanosheets (NS) were produced by the microwave assisted route and evaluated as nanofillers for a high-performance epoxy resin. They were used in various weight fractions ranging from 0.1 to 2 wt%. The synthesized CuO-NS were found to have a thickness of around 10 nm and length/width in the micro/submicro size range. These NS are highly crystalline mainly in the (11-1) and (111) directions and have the regular Ag and Bg Raman vibration modes. The mechanical tensile properties of the CuO-NS/epoxy nanocomposites, including their Young's modulus, stiffness, and load at fracture, were investigated. Moreover, the effect of degassing (voids removal) on the mechanical properties of these nanocomposites was studied. The obtained results showed a significant improvement in the stiffness by around 63% upon the addition of 0.5 wt% CuO-NS to the epoxy matrix. The load and stress at fracture were also improved. The test results show that degassing the initial solutions is essential and has a significant role in the mechanical properties of this nanocomposite. These results show that the microwave synthesized CuO-NS could overcome the agglomeration problem associated with other nanomaterials and might be quite useful as a reinforcement material for high-stiffness products.