1,2-dichloroethane based deposition of Graphene oxide Langmuir- Blodgett thin films

Abstract

Graphene oxide-a flexible, low cost material has attracted considerable interest in regards of its optical, mechanical and thermal properties. A Graphene oxide (GO) thin film finds wide range of applications: energy storage devices, conductive films, electronics and biomedical applications. So, their formation in a controlled manner for tailoring of their properties is an important research topic. Langmuir-Blodgett technique is well suited for producing tailor made GO thin films. In this work, uniform, transparent thin films of GO of variable thickness have been prepared using LB deposition process. The role of change in spreading solution composition, barrier compression rate as well as the sub-phase temperature on the film properties has been reflected upon. Surface pressure-area isotherms have been used to characterize the GO Langmuir layers on the water sub-phase prior to transfer onto solid substrate. The stability of the monolayers have been confirmed using hysteresis measurements of the GO Langmuir layers. The oscillating barrier measurements have been performed at different barrier compression rates for gaining an insight into the dissipation processes within the films by calculating visco-elastic parameters.Finally, the deposition of graphene oxide monolayers was done using Y-type deposition on glass substrates. Stable uniform graphene oxide thin films by 1, 2, 4 and 5 layer transfer for different barrier compression rates were deposited. AFM analysis of the deposited films shows that the films are continuous and smooth (low r.m.s. roughness). The roughness of the films increases with increasing number of transferred layers and smoother films are obtained for higher barrier compression rates.