Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-12T22:22:25.577Z Has data issue: false hasContentIssue false
  • English
  • Français

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]
Get access

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

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.)

References

REFERENCES

1.Li, J., Li, J., and Li, M.: Ultrasound irradiation prepare sulfur-free and lower exfoliate-temperature expandable graphite. Mater. Lett. 62, 2047 (2008).CrossRefGoogle Scholar
2.Weng, Z., Hand, E., and Ke, W.: Influence of expandable graphite on fire resistance and water resistance of flame-retardant coatings. Corros. Sci. 49(5), 2237 (2007).CrossRefGoogle Scholar
3.Toyoda, M. and Inagaki, M.: Heavy oil sorption using exfoliated graphite: New application of exfoliated graphite to protect heavy oil pollution. Carbon 38, 199 (2000).CrossRefGoogle Scholar
4.Jones, W.F. and Seth, B.B.: Asbestos-free gasket materials for turbines. J. Test. Eval. 21(1), 94 (1993).CrossRefGoogle Scholar
5.Chung, D.D.L.: Flexible graphite for gasketing, adsorption, electromagnetic interference shielding, vibration damping, electromagnetical applications, and stress sensing. J. Mater. Eng. Perform. 9(2), 161 (2000).CrossRefGoogle Scholar
6.Chugh, R. and Chung, D.D.L.: Flexible graphite as a heating element. Carbon 40(13), 2285 (2002).CrossRefGoogle Scholar
7.Yazici, M.S., Krassowski, D., and Prakash, J.: Flexible graphite as battery anode and current collector. J. Power Sources 141(1), 171 (2005).CrossRefGoogle Scholar
8.Gao, Q., Song, J., Liu, L., and Zhang, B.: Oxidation protection of graphite and B4C-modified graphite by a SiC-coating. Carbon 37(1), 149 (1999).CrossRefGoogle Scholar
9.Parashar, V.K., Raman, V., and Bahi, O.P.: Oxidation resistant material for carbon/carbon composites by the sol-gel process. J. Mater. Sci. Lett. 16(6), 479 (1997).CrossRefGoogle Scholar
10.Tsou, H.T. and Kowbel, W.: Design of multilayer plasma-assisted CVD coating for the oxidation protection of composite materials. Surf. Coat. Technol. 79(1), 139 (1996).CrossRefGoogle Scholar
11.Sogabe, T., Matsuda, T., Kuroda, K., Hirohata, Y., Hino, T., and Yamashina, T.: Preparation of B4C-mixed graphite by pressureless sintering and its air oxidation behavior. Carbon 33(12), 1783 (1995).CrossRefGoogle Scholar
12.Lee, Y.J. and Radovic, L.R.: Oxidation inhibition effects of phosphorus and boron in different carbon fabrics. Carbon 41, 1987 (2003).CrossRefGoogle Scholar
13.Sogabe, T., Okada, O., Kuroda, K., and Inagaki, M.: Improvement in properties and air oxidation resistance of carbon materials by boric oxide impregnation. Carbon 35(1), 67 (1997).CrossRefGoogle Scholar
14.Sorokina, N.E., Leshin, V.S., and Avdeev, V.V.: Electrochemical intercalation in the graphite-H2SO4-R (R=CH3COOH, H3PO4) system. J. Phys. Chem. Solids 65, 185 (2004).CrossRefGoogle Scholar
15.Kang, F., Zhang, T.Y., and Leng, Y.: Electrochemical synthesis of sulfate graphite intercalation compounds with different electrolyte concentrations. J. Phys. Chem. Solids 57, 883 (1996).CrossRefGoogle Scholar