Title
Oxidation of natural graphite in the laboratory and comparison with the synthetic graphite oxide, by means of thermal and spectroscopic techniques
Date Issued
01 December 2009
Access level
open access
Resource Type
journal article
Author(s)
Pisapia D.
Barrios C.
Martínez M.
Meléndez W.
Marrero S.
Escobar M.
A
Abstract
With the aim of establishing the probable natural formation of graphite oxide (GO) during the weathering and transport of this mineral, a highly crystalline graphite sample isolated from a Sierra Nevada Formation graphitic schist (Precambrian Age) collected at the State of Trujillo, was subject to controlled oxidation in an oven (T̃90°C) with a wet oxygen atmosphere through 25, 50 and 75 days of oxidation. This experimental design simuling weathering is equivalent to the natural alteration for the period of 8, 16 and 24 years, approximately. In addition, graphite oxide (GO) was synthesized by treatment with acid KMnO4. All samples and GO were characterized by means of XRD, Raman spectroscopy, thermogravimetric analysis and Fourier Transformed infrared spectroscopy. Oxydized samples exhibit a decrease in the crystallinity index and in the crystal thickness, reduction of the Raman signals corresponding to the ordered structure, displacements in the highest temperature towards lower values in thermogravimetry, and appearance of C - O strenght vibration in infrared spectroscopy. Such results indicate that a modification takes place in the graphite crystallinity, due to the expansion and incorporation of oxygen. The extent of the alteration do not reached the stage of GO formation.
Start page
249
End page
255
Volume
32
Issue
3
Language
Spanish
OCDE Knowledge area
Meteorología y ciencias atmosféricas
Scopus EID
2-s2.0-77952691254
Source
Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia
ISSN of the container
02540770
Sources of information: Directorio de Producción Científica Scopus