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Expandable graphite modification by boric acid

Published online by Cambridge University Press:  21 February 2012

Makhsud I. Saidaminov ,
Natalia V. Maksimova  and
Viktor V. Avdeev
Makhsud I. Saidaminov*
Affiliation:
Chemistry Department, Chair of Chemical Technology and New Materials, Moscow State University, 119992 Moscow, Russia
Natalia V. Maksimova
Affiliation:
Chemistry Department, Chair of Chemical Technology and New Materials, Moscow State University, 119992 Moscow, Russia
Viktor V. Avdeev
Affiliation:
Chemistry Department, Chair of Chemical Technology and New Materials, Moscow State University, 119992 Moscow, Russia
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Electrochemical oxidation of graphite in mixed solutions of H2SO4–H3BO3 with various mass ratios was investigated. The potential correction to concentration in the formation of graphite intercalation compound II stage in the system graphite–H2SO4–H3BO3 was determined and compared with other systems. Boric acid was shown not to be co-intercalated with sulfuric acid into graphite matrix, but to be distributed on the surface of expandable graphite (EXP). The amount of boric acid on EXP depends on concentration of H3BO3 in electrolyte and it ranges from 3.7 to 11.0 wt%. Content of boric oxide formed after thermoshocking is equal to 3–9 wt% in exfoliated graphite (EG). Modification resulted in reducing specific surface area of EG. As the pores in modified EG were blocked by boric oxide, the temperature of oxidation of the EG and graphite foil increased by 200 °C.

Keywords

Electrochemical synthesisIntercalationThermogravimetric analysis
Type
Articles
Information
Journal of Materials Research , Volume 27 , Issue 7 , 14 April 2012 , pp. 1054 - 1059
Copyright
Copyright © Materials Research Society 2012

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