Hostname: page-component-7b7567c8c-kwt9d Total loading time: 0 Render date: 2026-11-14T16:32:54.159Z Has data issue: false hasContentIssue false

Intercalation-Desorption Studies of Graphite Nitrate

Published online by Cambridge University Press:  15 February 2011

T. Dziemianowicz
Affiliation:
Department of Chemical Engineering, University of Pennsylvania Philadelphia, PA 19104
K. Leong
Affiliation:
Department of Chemical Engineering, University of Pennsylvania Philadelphia, PA 19104
W.C. Forsman
Affiliation:
Department of Chemical Engineering, University of Pennsylvania Philadelphia, PA 19104
Get access

Abstract

A new model for intercalation kinetics is presented whick takes into account both nucleation of the interlaminar spaces and intercalant layer growth. For nitric acid intercalation, the nucleation constant, β, ranges from 1.25×10−3 to 10−4 sec−1 depending on graphite type (HOPG > powder > fibers); the corresponding range of effective diffusivities, D, is 2.5×10−5 to 10−10 cm2/sec. It is emphasized that effective diffusivities obtained from sorption kinetics are reaction enhanced.

Stepwise isothermal desorption experiments show that the diffusivities of HNO3 neutrals are lower than the effective diffusivities on sorption. At desorptive equilibrium, intercalant retention is in the order HOPG > fibers > powder. In HOPG, resistance is constant over the desorptive transition stage II → III → IV; during the stage IV → V → VI regime (dynamic vacuum), resistance doubles. A similar resistance gain is noted on desorption of neturals from nitrated graphite fibers.

Information

Type
Research Article
Copyright
Copyright © Materials Research Society 1983

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable