A new class of hybrid materials based on carbon nanotubes (CNT) rooted on smectite clays (SWy) was synthesized by catalytic chemical vapor deposition (CCVD) method, and studied to be introduced in a perfluorosulfonic acid (Nafion) membrane. Side-wall chemical oxidation and organo-functionalization of the CNT was performed using organic ester molecules containing hydrophilic groups (−RSO3H). SWy–CNT nanoadditives were incorporated in the polymer by solution-precipitation method producing highly homogeneous nanocomposite membranes with outstanding mechanical properties. Materials were characterized by a combination of techniques (TGA, Raman, FT-IR, SEM, TEM, and DMA), while a deep investigation on the water transport properties was performed by NMR methods (PFG and relaxation times). Membranes containing SWy–oxCNT–RSO3H nanoadditives are able to guarantee a very high proton diffusion in “quasi-anhydrous” conditions. Proton mobility is ensured by a correct network created from the long nanotubes (well distributed through the clay nanoplatelets) appropriately functionalized with acid groups. Remarkable are the electrochemical results: the best membrane reaches conductivities of 7 × 10–2 S cm–1 at 120 °C and 30% RH, 1 order of magnitude higher than pristine polymer, and a rather high value in the current panorama of the PEMFCs.

Clay–Carbon Nanotubes Hybrid Materials for Nanocomposite Membranes: Advantages of Branched Structure for Proton Transport under Low Humidity Conditions in PEMFCs

Simari, Cataldo;Policicchio, Alfonso;Perrotta, Ida;Nicotera, Isabella
2016-01-01

Abstract

A new class of hybrid materials based on carbon nanotubes (CNT) rooted on smectite clays (SWy) was synthesized by catalytic chemical vapor deposition (CCVD) method, and studied to be introduced in a perfluorosulfonic acid (Nafion) membrane. Side-wall chemical oxidation and organo-functionalization of the CNT was performed using organic ester molecules containing hydrophilic groups (−RSO3H). SWy–CNT nanoadditives were incorporated in the polymer by solution-precipitation method producing highly homogeneous nanocomposite membranes with outstanding mechanical properties. Materials were characterized by a combination of techniques (TGA, Raman, FT-IR, SEM, TEM, and DMA), while a deep investigation on the water transport properties was performed by NMR methods (PFG and relaxation times). Membranes containing SWy–oxCNT–RSO3H nanoadditives are able to guarantee a very high proton diffusion in “quasi-anhydrous” conditions. Proton mobility is ensured by a correct network created from the long nanotubes (well distributed through the clay nanoplatelets) appropriately functionalized with acid groups. Remarkable are the electrochemical results: the best membrane reaches conductivities of 7 × 10–2 S cm–1 at 120 °C and 30% RH, 1 order of magnitude higher than pristine polymer, and a rather high value in the current panorama of the PEMFCs.
2016
Carbon nanotubes,Composites,Fluoropolymers,Membranes,Polymers
File in questo prodotto:
File Dimensione Formato  
acs.jpcc.5b11871.pdf

solo utenti autorizzati

Tipologia: Versione Editoriale (PDF)
Licenza: Copyright dell'editore
Dimensione 5.43 MB
Formato Adobe PDF
5.43 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11770/334763
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 51
  • ???jsp.display-item.citation.isi??? ND
social impact