Journal of Materials Science

, Volume 33, Issue 9, pp 2251–2254

The chemistry of cements formed between zinc oxide and aqueous zinc chloride

  • J. W Nicholson
  • L Parker
Article

DOI: 10.1023/A:1004327018497

Cite this article as:
Nicholson, J.W. & Parker, L. Journal of Materials Science (1998) 33: 2251. doi:10.1023/A:1004327018497

Abstract

A series of cements has been prepared from zinc oxide powder and aqueous zinc chloride, using solutions corresponding to concentrations of 20%, 30%, 40%, 50% and 60% and a ratio of ZnO powder to zinc chloride solution of 1:1. As with cements of the zinc oxide/zinc nitrate system, these ZnO/ZnCl2 cements were found to be weak in compression (not exceeding 10 MPa) with strength rising with increasing concentration of ZnCl2. The pH change as the reaction proceeded was monitored and generally showed a rapid increase, followed by a slight decrease, and a subsequent slower increase. This is assumed to arise because the doubly charged aquo-zinc cation, Zn(H2O)2+n (n=4 or 6) behaves as a weak acid, due to so-called salt hydrolysis: Zn(H2O)2+n+H2O⇌ZnOH(H2O)+(n-1)+H3O+ and reacts to form a salt, thus setting up a classic weak acid/salt buffer system. Finally, cements were stored in water for 1 month, and were generally found to increase in mass during the first week, with the greatest increase occurring in the cement made from 20% ZnCl2 solution. All cements lost mass between 1 week and 1 month, showing them to be sparingly soluble at room temperature. © 1998 Chapman & Hall

Copyright information

© Chapman and Hall 1998

Authors and Affiliations

  • J. W Nicholson
    • 1
  • L Parker
    • 2
  1. 1.Biomaterials DepartmentKing's College School of Medicine and DentistryLondonUK
  2. 2.Science DepartmentThe College of North-East LondonLondonUK