Qingbin Zheng - Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
Biao Zhang - Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
S. Hamed Aboutalebi - Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
Zhendong Huang - Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong

This paper reviews our recent research activities in the use of graphene sheets for various multifunctional applications. Highly conducting, transparent graphene films are prepared by transfer printing followed by thermal treatment. It is shown that additional acid and doping treatments reduce the sheet resistance by about 20-50% with improved transmittance. Transparent conductive films are also produced using ultra-large graphene oxide (UL-GO) sheets that are deposited layer-by-layer using the Langmuir-Blodgett (L-B) assembly technique. A remarkable sheet resistance of ~500 2/sq. at 90% transparency is obtained, which outperforms the graphene films grown on a Ni substrate by chemical vapor deposition. Spontaneous formation of lyotropic nematic liquid crystal is identified upon the addition of UL-GO sheets in water above a critical concentration of about 0.1 wt%. It is proposed that the self-assembled brick-like GO nanostructure can be applied in many areas, such as energy storage devices and nanocomposites with a high degree of orientation. Two different types of SnO2-graphene-carbon nanotube (SnO-G-CNT) composites in the form of particles and papers are synthesized using GO as precursor for application as anode material in rechargeable Liion batteries. The electrodes made from these SnO2-G-CNT composites deliver remarkable capacities arising from the high specific capacity of SnO, nanoparticles and the excellent cycleability of G-CNT paper.

Transparent conductors, Langmuir-Blodgett assembly, Liquid Crystal, SnO2-graphenecarbon nanotube composites, Energy storage