TitleFabrication of highly conductive and flexible hybrid carbon nanofilms
NameJeong, Min (author), Sheridan, John (chair), He, Huixin (internal member), Jäkle, Frieder (internal member), Lockard, Jenny (internal member), Rutgers University, Graduate School - Newark,
DescriptionCarbon nanotubes (CNTs) and graphene are the two most conductive members among carbon nanomaterials. For industrial applications, these nanomaterials are attracting great attention for fabrication of flexible conducting films. However, the electronic performance of either CNT or graphene film has yet to reach their theoretical expectations due to high resistance and tunneling/Schottky barriers at the junctions between nanotubes or between graphene sheets. One of the important observations was that CNTs and graphene sheets can be crosslinked during and/or after film fabrication, which largely decrease inter-tube or inter-sheet resistance. However, the current solution-processing techniques for the film fabrication, such as spin coating, layer-by-layer assembly, and vacuum filtration have disadvantages and limitations. In this thesis, we developed an efficient film assembly approach as well as a facile transfer process. The first chapter of this thesis provides an overview on structure and properties of CNTs and graphene. In the second chapter, we used our newly developed microwave-enabled dispersion technique to synthesize highly conductive dispersible CNTs and graphene with low-density of oxygen-containing groups, without a need of surfactant/stabilizer. As we fabricated Microwave-enabled low-oxygen multi-walled nanotube only (ME-LOMWNT-only), Microwave-enabled low-oxygen graphene only (ME-LOGr-only), and ME-LOMWNT/ME-LOGr hybrid films using vacuum filtration, we found that the hybrid films are highly conductive relative to either the ME-LOMWNT-only or ME-LOGr-only film. The conductivity of the hybrid films depends on their composition, where a weight ratio of 97/3 between MWNTs and graphene reached the highest conductivity of 247,812 S m-1, which is two times higher than those of SWNT/graphene hybrid films reported by Coleman et al.8 In this work, we found crosslinks between MWNTs and graphene, which could be further promoted in acidic environment. These crosslinks between MWCNT and graphene enhanced the film conductivity. The aim of the third chapter was to fabricate high quality graphene films and MWNT/graphene hybrid films using interfacial self-assembly approach. We observed the different assembly behavior of ME-LOMWNT and ME-LOGr due to their different shape and surface energy. Then, we optimized the parameters to fabricate high quality of ME-LOMWNT/ME-LOGr hybrid films. Moreover, we developed an efficient approach to transfer the self-assembled film at this water/oil interface onto substrates for future electrical characterization and device fabrications.
NoteIncludes bibliographical references
Noteby Min Jeong
CollectionGraduate School - Newark Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.