Expanded graphite-based electrically conductive composites as bipolar plate for PEM fuel cell

Dhakate, Sanjay R.; Sharma, Sanjeev; Borah, Munindra; Mathur, R.B.; Dhami, T.L.

doi:10.1016/j.ijhydene.2008.09.004

Cited by 142 publications

(84 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Expanded graphite was obtained by the method of chemical oxidation [11]. The natural graphite was dried at 75 • C in a vacuum oven for 10 h. Then, it was blended for 12 h with a 3:1 sulfuric and nitric mixture in order to form the graphite inserted compound.…”

Section: Preparation Of Expanded Graphitementioning

confidence: 99%

“…The drawback is the difficult dispersion of the graphite in the polymer matrix fact that can be overcome by modifying its surface. For example, graphite can be expanded by chemical oxidation and thermal shock in order to increase the size of channels, improving thus the interaction with the polymer matrix [11]. In this work, polyurethane has been synthesized and modified with different amounts of expanded graphite (EG) as a conductive filler.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An experimental study of dynamic behaviour of graphite–polycarbonatediol polyurethane composites for protective coatings

Gómez

Culebras

Cantarero

et al. 2013

Applied Surface Science

View full text Add to dashboard Cite

Segmented polycarbonatediol polyurethane has been synthesized and modified with different amounts of graphite conductive filler (from 0 to 50 wt %). Thermal and Dynamical thermal analysis behavior of the composites clearly indicates the changes in polyurethane relaxations upon addition of graphite. Broadband Dielectric Spectroscopy has been used to study the dielectric properties of the composites in the frequency range from 10 −2 to 10 7 Hz and temperature window of -140 to 170 • C. Conductivity, relaxation processes associated with different molecular motions, Maxwell-Wagner-Sillars and electrode polarization are discussed and related with the graphite content.

show abstract

Section: Preparation Of Expanded Graphitementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An experimental study of dynamic behaviour of graphite–polycarbonatediol polyurethane composites for protective coatings

Gómez

Culebras

Cantarero

et al. 2013

Applied Surface Science

View full text Add to dashboard Cite

show abstract

“…Traditionally, bipolar plates are made from non-porous graphite, because of its good electronic conductivity and high chemical stability in PEM fuel cell environments. However, its low toughness, gas permeability and the difficulties in machining gas flow channels increase fabrication costs and the overall size of a PEFC stack [6]. In lieu of this, considerable effort has been made into the development of metallic bipolar plates, from materials such as stainless steel and titanium and aluminum alloys [7,8].…”

Section: Introductionmentioning

confidence: 99%

Corrosion behavior of a ZrCN coated Ti alloy with potential application as a bipolar plate for proton exchange membrane fuel cell

Huang

et al. 2016

Journal of Alloys and Compounds

View full text Add to dashboard Cite

a b s t r a c tTo improve the corrosion resistance, surface electrical conductivity and wettability of Tie6Ale4V used in polymer electrolyte membrane fuel cell (PEMFC), a ZrCN nanocrystalline coating was deposited on Ti e6Ale4V substrate using double cathode glow discharge technique. The new coating exhibited a nanocomposite structure, consisting of amorphous C, CN x and nanocrystalline ZrCN. The effect of the HF concentrations on the corrosion behavior of the coating was investigated by potentiodynamic, potentiostatic polarizations and electrochemical impedance spectroscopy (EIS) in a simulated the operating conditions of a PEMFC. With increasing HF concentrations, the corrosion potential (E corr ) decreased and the corrosion current density (i corr ) of the ZrCN coating increased, indicating that corrosion resistance decreased with the increase of HF concentrations. However, at any given concentration of HF, the corrosion resistance of the ZrCN coating was significantly higher than that of uncoated Tie6Ale4V. The results of EIS measurements showed that with increasing the concentration of HF, the resistance of the passive film (R b ) formed on the ZrCN coating decreased slightly, being of the order of magnitude of 10 7 U cm 2 , which was an improvement by four orders of magnitude compared to uncoated Ti-6A1-4V. At a compaction force of 140 N cm À2 , no perceptible difference in the interfacial contact resistance (ICR)of ZrCN-coated Ti-6A1-4V was observed before and after potentiostatic polarization for 120 min, and its ICR values were reduced by one order of magnitude in comparison to that of uncoated Ti-6A1-4V. Moreover, ZrCN-coated Ti-6A1-4V exhibited a much low surface wettability than uncoated Tie6Ale4V alloy, which was beneficial for both water management and improving corrosion resistance.

show abstract

“…Finally, they were dried in a vacuum oven at 293 K. Segmented thermoplastic polyurethanes are copolymers formed by hard and soft segments. In the present thesis, 4,4'−diphenylmethane diisocyanate (MDI) (see Expanded graphite was obtained by the method of chemical oxidation (Dhakate, et al, 2008). The natural graphite was dried at 348 K in a vacuum oven for 10 h. Then, it was blended for 12 h with a 3:1 sulfuric and nitric mixture in order to form the graphite inserted compound.…”

Section: Synthesis Of Vp/ba Copolymersmentioning

confidence: 99%

“…This fact can be overcome by modifying its surface. For example, graphite can be expanded by chemical oxidation and thermal shock in order to increase the size of channels, improving thus the interaction with the polymer matrix (Dhakate, et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

A contribution to the study of the molecular mobility in polymeric materials by Thermal and Dielectric Analysis

Foj¹,

Belén²

View full text Add to dashboard Cite

T h e s i s S u p e r v i s o r : P R O F . D r . M a r í a J e s ú s S a n c h i s S á n c h e z t o o b t a i n t h e d e g r e e o f D o c t o r o f P h i l o s o p h y a t t h e U n i v e r s i t a t P o l i t è c n i c a d e V a l è n c i a Prof. Dr. María Jesús Sanchis SánchezThe work presented in this thesis was carried out at the Universitat Politècnica de València and was financially supported by the Spanish Ministry of Economy and Competitiveness (Projects Nos. MAT2008-06725-C03-03 and MAT2012-33483)."Cuando quieres algo, todo el Universo conspira para que ACKNOWLEDGEMENTSTras estos años de trabajo, llega el momento de mostrar mi agradecimiento a todas las personas que me han acompañado y apoyado durante el desarrollo de mi tesis doctoral.En primer lugar, me gustaría expresar mi gratitud a mi directora de tesis María J.Sanchis por su inestimable ayuda durante todos estos años. Muchas gracias por confiar en mí, por darme esta oportunidad y por las incalculables horas invertidas tanto para el desarrollo de esta tesis como al mío propio.También me gustaría agradecer a mis estimadas compañeras Marta Carsí y Pilar Ortiz su ayuda y amistad en este largo recorrido que suponer realizar una tesis doctoral. He aprendido mucho de vosotras tanto científica como personalmente. En este punto, no puedo olvidarme de mi querida Aurora Alonso, que pese a no formar parte de nuestro grupo de investigación, me ha apoyado, aconsejado y dado su amistad durante todos estos años.Quiero mostrar mi agradecimiento a los profesores José M. García y Félix C. García ABSTRACTThe development of new and more complex polymeric materials involves challenging problems to basic sciences. The relationship between structure and molecular dynamics assumes great importance for the future development of novel technologies based on such polymers. Thus, the understanding of how small changes in the chemical structure affect the properties of the material is essential to progress in the technological and scientific area. An in-depth analysis of the molecular mobility leads to establish the structure-properties relationships. On this basis, the main aim of the present work is to study the molecular mobility of two different families of polymeric materials. For this purpose, the experimental techniques mainly used were Differential Scanning Calorimetry (DSC) and Dielectric Relaxation Spectroscopy (DRS) (Chapter 3).The first family of polymers characterized was a series of chemically cross-linked copolymers composed by Vinylpyrrolidone (VP) and Butyl Acrylate (BA) monomers. The study was divided in two parts, which are collected in Chapter 4 and 5.In the first place, Chapter 4 contains the influence of the monomer molar ratio (XVP/YBA) on the copolymer properties. Thus, a Fourier Transform Infrared Spectroscopy (FTIR) analysis verified dipole-dipole interactions between amide groups. The influence of these interactions on several parameters related to the molecular mobility was evidenced by the DSC, DRS and Dynamic Mechanical Analysis (DMA) techni...

show abstract

Expanded graphite-based electrically conductive composites as bipolar plate for PEM fuel cell

Cited by 142 publications

References 21 publications

An experimental study of dynamic behaviour of graphite–polycarbonatediol polyurethane composites for protective coatings

An experimental study of dynamic behaviour of graphite–polycarbonatediol polyurethane composites for protective coatings

Corrosion behavior of a ZrCN coated Ti alloy with potential application as a bipolar plate for proton exchange membrane fuel cell

A contribution to the study of the molecular mobility in polymeric materials by Thermal and Dielectric Analysis

Contact Info

Product

Resources

About