Affordable Access

Publisher Website

Adsorption of n-Alkanes on Plasma-Oxidized High-Strength Carbon Fibers

Authors
Journal
Journal of Colloid and Interface Science
0021-9797
Publisher
Elsevier
Publication Date
Volume
247
Issue
2
Identifiers
DOI: 10.1006/jcis.2001.8134
Disciplines
  • Physics

Abstract

Abstract The objective of this work was to characterize the degree of heterogeneity brought about by oxygen plasma treatment of carbon fibers by studying its effects on the adsorption of n-alkanes. Untreated and unsized high-strength carbon fibers were subjected to oxygen plasma treatments with different degrees of severity. A sample of the same material oxidized following a standard industrial method was also studied for comparison. Adsorption of C5–C10n-alkanes at 303–353 K was measured by inverse gas chromatography (IGC). Elution peaks were symmetrical for the fresh and industrially oxidized samples; however, a large extent of asymmetry was observed for the plasma-treated fibers. Differences in surface heterogeneity were quantified in terms of several adsorption thermodynamic magnitudes. Differential heats of adsorption exhibited values similar to those corresponding to the probe–basal plane interaction. The dispersive component of the surface tension of the solids increased clearly upon plasma oxidation, the increase being systematic according to the severity of plasma treatment. It can be concluded that plasma oxidation generates high-surface-energy sites responsible for trapping of n-alkane molecules, this effect being more marked as the chain length increases. The possibility of this effect being associated to creation of micropores was ruled out on the basis of volumetric CO2 adsorption experiments and IGC measurements at finite dilution. Scanning tunneling microscopy observations allowed us to establish a possible connection between fiber surface nanostructure and IGC results. The sites accessible to n-alkane molecules in the industrially oxidized sample seem to be highly disordered, thus leading to a weaker interaction with the adsorbate.

There are no comments yet on this publication. Be the first to share your thoughts.

Statistics

Seen <100 times
0 Comments

More articles like this

Adsorption of n-alkanes on plasma-oxidized high-st...

on Journal of Colloid and Interfa... Mar 15, 2002

High resolution N2adsorption isotherms at 77.4 K a...

on Journal of Colloid and Interfa... Jan 01, 2012

Adsorption of polar probe molecules on plasma-oxid...

on Fuel Processing Technology Jan 01, 2002

High-resolution NMR spectra of n-alkanes penetrati...

on Magnetic Resonance in Chemistr... August 2008
More articles like this..