ISSN:
1435-1536
Keywords:
Surfacefreeenergy
;
modifiedcarbonfibers
;
tensiometry
;
work ofadhesion
;
ESCA
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Surface free energy of various carbon fibers was determined by tensiometric method in three different procedures. The dispersiveγ s d and the nondispersiveγ s p components were separately determined by contact angle measurements in two-phase system, formamide-n-alkanes. Theγ s p increased by oxidation and decreased by hydrogen reduction, while theγ s d remained almost constant.Theγ s p value determined from contact angle of water/ethyleneglycol solution tended to become higher. The critical surface free energy was in harmony with the total free energy determined from formamide-n-alkanes system as long as liquids were properly selected. The formation of oxygen-containing functional groups was evidenced by ESCA, and the surface [O]/[C] ratio was related linearly to the surface polarity defined byγ s p [γ s d +γ s p ] Oxidation in liquid phase resulted in the formation of both hydroxyls and carboxyls, while only hydroxyls were formed in gas phase. The interfacial shear strength of the fiber-epoxy resin could be closely correlated with thermodynamical work of adhesion calculated on the basis of surface free energy and its component.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01410420
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