A Tritium–Hydrogen Exchange Procedure for Determining the Concentration of Exchangeable Sites on PAN Based Carbon Fibres

A non-destructive tritium–hydrogen exchange procedure has been developed in order to determine the concentration of exchangeable hydrogens on surfaces, and in this particular instance it has been used on carbon fibres. The results show that the concentrations of ‘active sites’ on the surfaces of Courtaulds Grafil XAS and XAU carbon fibres are 2.61 and 0.08 μmol g−1 respectively. When the XAS fibres are subjected to a standard methylation procedure the concentration of exchangeable hydrogens is reduced to 0.79 μmol g−1.On the other hand, when XAU fibres are subjected to oxidation in concentrated nitric acid, the concentration of exchangeable hydrogens is increased to 10.27 μmol g−1.

[1]  Zhihong Wu,et al.  XPS/ISS Investigation of Carbon Fibers Sequentially Exposed to Nitric Acid and Sodium Hydroxide , 1996 .

[2]  C. Jones,et al.  Study of the interaction of carbon fibre surfaces with a monofunctional epoxy resin , 1996 .

[3]  Yun Lu,et al.  Pretreatment of carbon fibre and its effect on adhesion in reinforced epoxy composites , 1996 .

[4]  Zhihong Wu,et al.  Grafting isocyanate-terminated elastomers onto the surfaces of carbon fibers: Reaction of isocyanate with acidic surface functions , 1996 .

[5]  M. Alexander,et al.  Effect of electrolytic oxidation upon the surface chemistry of type A carbon fibres: III. Chemical state, source and location of surface nitrogen , 1996 .

[6]  P. Sherwood,et al.  X‐ray photoelectron spectroscopic studies of carbon‐fiber surfaces. 19. Surface chemical changes during electrochemical oxidation in base , 1995 .

[7]  Charles Q. Yang,et al.  Comparison of photoacoustic, diffuse reflectance and transmission infrared spectroscopy for the study of carbon fibres , 1995 .

[8]  Zhihong Wu,et al.  Bonding epoxide functions to nitric acid-oxidized carbon fibers using epichlorohydrin; A reliable analytical determination of epoxide functions on fiber surfaces , 1995 .

[9]  Zhihong Wu,et al.  Nitric acid oxidation of carbon fibers and the effects of subsequent treatment in refluxing aqueous NaOH , 1995 .

[10]  M. Alexander,et al.  The chemical environment of nitrogen in the surface of carbon fibres , 1994 .

[11]  Tiejun Wang,et al.  X-ray Photoelectron Spectroscopic Studies of Carbon Fiber Surfaces. 17. Interfacial Interactions between Phenolic Resin and Carbon Fibers Electrochemically Oxidized in Nitric Acid and Phosphoric Acid Solutions, and Their Effect on Oxidation Behavior , 1994 .

[12]  L. Ibarra,et al.  Functionalization of carbon fibres , 1994 .

[13]  K. J. Hüttinger,et al.  Evidence for chemical bond formation between surface treated carbon fibres and high temperature thermoplastics , 1994 .

[14]  G. Désarmot,et al.  Improvement of fibre/matrix bonding in carbon-fibre/acrylic composites by electron-irradiation: Concept of difunctional chemical coupling agent , 1994 .

[15]  L. W. Jenneskens,et al.  The relation between carbon-fibre surface treatment and the fibre surface microstructure , 1994 .

[16]  I. Sutherland,et al.  An investigation of carbon fibre surface chemistry and reactivity based on XPS and surface free energy , 1993 .

[17]  J. Castle,et al.  Determination of the acidity of carbon-fibre surfaces by means of X-ray photoelectron spectroscopy adsorption isotherms , 1992 .

[18]  C. R. Davis,et al.  Development of surface acidity during electrochemical treatment of pan-carbon fibers , 1992 .

[19]  D. Briggs,et al.  TOF‐SIMS satudies of carbon‐fibre surfaces and carbon‐fibre composite fracture surfaces , 1991 .

[20]  J. Hughes.  The carbon fibre/epoxy interface: a review , 1991 .

[21]  A. Salvi,et al.  XPS determination of oxygen‐containing functional groups on carbon‐fibre surfaces and the cleaning of these surfaces , 1990 .

[22]  J. Koenig,et al.  Surface characterization of carbon fibers and interphase phenomena in epoxy-reinforced composites , 1990 .

[23]  A. Ishitani,et al.  XPS study of the carbon fiber matrix interface , 1990 .

[24]  J. Koenig,et al.  Surface characterization of graphitized carbon fibers by attenuated total reflection fourier transform infrared spectroscopy , 1990 .

[25]  P. Grenier,et al.  Surfaces of carbon fibres characterized by inverse gas chromatography , 1989 .

[26]  F. Sturm,et al.  Anodic oxidation of high modulus carbon fibres in sulphuric acid , 1988 .

[27]  J. Donnet,et al.  Contribution to the study of basic surface groups on carbons , 1987 .

[28]  John R. Jones,et al.  Handbook of tritium NMR spectroscopy and applications , 1985 .

[29]  P. Sherwood,et al.  X-ray photoelectron spectroscopic studies of carbon-fibre surfaces. Part 4.—The effect of electrochemical treatment in nitric acid , 1984 .

[30]  John R. Jones.  The ionisation of carbon acids , 1973 .

[31]  J. Grundy.  Esterification of sterically hindered carboxylic acids using dimethyl sulphate , 1972 .

[32]  W. Heck,et al.  Surface Oxides of Carbon , 1964 .

[33]  V. Gold,et al.  The principles of hydrogen isotope exchange reactions in solution , 1955 .