GNT: Graphene and Nanotubes

INSTITUTO DE CARBOQUÍMICA (CSIC)

UNIVERSIDAD DE ZARAGOZA

PHD DEFENSE

Candidate:  Pablo Jiménez Manero

Title: Nanostructured Materials based on Polyaniline, Carbon Nnaotubes and Graphene

Directors: Dr. Ana Benito and Dr. Wolfgang Maser (Instituto de Carboquímica, CSIC)

Place: Instituto de Carboquímica (CSIC), Salón de Actos

Date/Time: Tuesday, 8th of March 2011, 11:30 am

Board of Examiners:

Prof. Fernando Langa (Univ. Castilla La Mancha)

Prof. M. Teresa Martínez (Instituto de Carboquímica, CSIC)

Prof. Luis Oriol (Univ. Zaragoza)

Dr. M. José Esplandiú (CIN2, CSIC)

Dr. David Mecerreyes (Polymat, Univ. Basque Country)

Dr. Cristina Vallés (Instituto de Carboquímica, CSIC)

Prof. Milagros Piñol (Univ. Zaragoza)

Summary:

In this thesis were synthesized, characterized and processed composite materials based on a intrinsically conducting polymer  (polyaniline) and two carbon nanostructured materials, namely carbon nanotubes and graphene. In both cvases, in situ polymerization of aniline was empolyed successfully for obtaining composites with a controlled morphology at the nanoscale. The resulting materials further more presented a set of interesting properteis, intrinsci to its components.

In what concersn carbon nanotubes, its presence modifies the fibrilar morphology of polyaniline (PANI) established durign the in situ polymerization of aniline. Characterization of the obtained composites revealed, on one hand, the influence of the morphology on specific properteis of the composites, such as their electrical conductivity and optical absorbance. The principal advantages derived from the nanostrcutured morphology of these composites is their improved processing possibilities from aqueous dissolutions. The excellent water dispersibiltiy allows the preparation of films, fibers, and gels of the composites, the fabricaiton of blends with water soluble polyemrs and their incorporation in devices such as solar cells or supercapacitors.

In what concerns graphene, the use of an hydrophilic derivative of graphene, namely graphene oxide (GO) facilitates the synthesis of PANI-GO composites having a laminar morphology. Upon chemical reduction in order to impnrove th electrical properties of GO, present in the composite, an atypical oxidation state of PANI was established, due to the creation of a solid state charge transfer complex at the interface of PANI and reduced GO. Characterization of the compostie clearly revealed this type of itneraction, which, moreover, leads to the appearance of some unexpected proeprteis such as a good degradation stability and water dispersibiltiy.