Multilayer Graphene Films Obtained by Dip Coating Technique

A dip coating system was projected and constructed to deposit a large range of thin films onto solid substrates. A microcontroller was used to control the deposition system. As an example of application multilayer graphene (MLG) films were deposited onto glass slices in order to obtain conductive films with relatively good light transmittance. The MLG flakes were obtained using natural graphite and isopropyl alcohol resulting in three dispersions treated in ultrasound for 30, 60 and 90 minutes, respectively. Using atomic force microscopy, UV-Vis spectrometry and an electrometer the film characterizations were performed. MLG flakes about 13 nm thick, 10 mµ² of area were observed using AFM. In films obtained with 35 immersions the electrical resistance and the resistance sheet reached 1.8 kΩ and 1.9kΩ/square respectively. The light transmittance reached 10-20% while films obtained with dispersions treated for 60 and 90 minutes were electrically continuous. Thus, conductive films can be used in chemiresistor sensors, electrochemical and supercapacitors electrodes.

Keywords:
graphene; thin films; dip coating; conductive films; AFM