Structure and antibacterial activity of Ce3+ exchanged montmorillonites

Four kinds of Ce³⁺ exchanged montmorillonites (Ce/MMTs) were prepared by an ion-exchange reaction, and characterized with energy dispersive X-ray analysis (EDX), X-ray difference (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The surface properties and antibacterial activity of Ce/MMTs were also investigated. The chemical compositions of Ce/MMTs were determined, and the cerium of Ce/MMTs was confirmed to be present as trivalent cerium state. The d₀₀₁ basal spacings of Ce/MMTs were enlarged with the enhancement of the cerium contents, and the particles were formed with irregular shape. On increasing the Ce contents of Ce/MMTs, the special surface areas were decreased, but the total pore volumes and the average pore sizes were increased. The antibacterial activity of Ce/MMTs is increased with increasing the cerium contents, and 1.5 g/L of Ce/MMT-3 containing 11.46wt.% of curium could remove all the Staphylococcus aureus and more than 99.9% of the Escherichia coli within 24.0 h of contact. Moreover, Ce/MMTs displayed bactericidal activity.