A. Oya et al., ANTIMICROBIAL AND ANTIFUNGAL AGENTS DERIVED FROM CLAY-MINERALS .5. MONTMORILLONITE AND SAPONITE CONTAINING SOME ANTIMICROBIAL AMMONIUM-IONS, Journal of Materials Science, 29(1), 1994, pp. 11-14
Five antimicrobial ammonium cations were intercalated into two clay mi
nerals (saponite and montmorillonite) by using ion-exchange reaction.
About 90% of the cation exchange capacities of the clay minerals were
replaced by ammonium ions with a few exceptions. The resultant complex
es exhibited antimicrobial activity against both Staphylococcus aureus
and Escherichia coli. After heating to 250-degrees-C, the antimicrobi
al activity was kept for the complexes with aromatic ammonium ions but
not for those with aliphatic ammonium ions. The complexes were treate
d with deionized water and a 3% aqueous solution of sulphuric acid to
examine the elution of the ammonium ions. The elution finished within
1 day, with retention of 80% of the aromatic ammonium ions. Aliphatic
ammonium ions remained in smaller amounts.