Evaluation of mechanical, electrical and thermal properties of pristine graphene laminates

  • Dian Yi

Student thesis: Unknown

Abstract

Due to the intrinsic high thermal conductivity, electrical conductivity and mechanical properties of graphene it has been suggested as a candidate building block of next generation thermal management and electromagnetic interference shielding integrated material. Electrochemical exfoliation, as an effective route to produce high quality graphene sheets in an environmentally friendly manner, is regarded as a practical way for mass production of graphene. In this thesis I demonstrate a fabrication process for producing flexible, electrically conductive and thermally conductive graphene laminate. The flexible, free standing graphene laminate has been fabricated directly by blade-coating of electrochemically exfoliated pristine few-layer graphene formulations. The exfoliated graphene sheets were produced using the anodic electrochemical exfoliation in aqueous solution of inorganic salts. Some optimization of as-prepared graphene laminates was also investigated by applying pressure and annealing these at elevated temperatures. The resulting laminates exhibit an excellent electrical conductivity of up to 1.2105 S·m-1 and a thermal conductivity of up to 40 W·m-1·K-1 and can be used for high-efficiency EMI shielding. In addition, we have found an unusual relation between the thermal diffusivity of the gas in the graphene laminate and the surrounding pressure, which we tried to explain using specular reflection phenomenon in the Knudsen regime and the factor of tortuosity. However, the nonmonotonic behaviour and hysteresis effect observed in this relation is unexplainable and requires future research.
Date of Award6 Jan 2021
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorKonstantin Novoselov (Supervisor) & Andrey Kretinin (Supervisor)

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