Title: SILVER AND-OR COPPER VERMICULITES AND THEIR ANTIBACTERIAL EFFECT |
Authors: Hundáková Marianna, Valášková Marta, Tomášek Vladimír, Pazdziora Erich and Matějová Kateřina |
DOI: 10.13168/AGG.2013.0009 |
Journal: Acta Geodynamica et Geomaterialia, Vol. 10, No. 1 (169), Prague 2013 |
Full Text: PDF file (2.2 MB) |
Keywords: vermiculite, silver, copper, structure characterization, antibacterial effect |
Abstract: Vermiculite (V) from Brazil with aqueous solutions AgNO3 and/or Cu(NO3)2 was used for preparation of nanocomposites
V/Ag, V/Cu, V/AgCu and V/CuAg using two procedures and their effect on bacteria was compared. Structural changes were
evaluated using X-ray diffraction (XRD) analysis, Infrared spectroscopy (IRS) and Scanning electron microscopy (SEM).
Elemental chemical composition was determined using X-ray fluorescence (XRF) analysis and the solutions were analyzed by
Atomic emission spectroscopy with inductively coupled plasma (AES-ICP).
Antibacterial properties of Ag- and Cu-vermiculites and combined Ag/Cu-vermiculites were tested on two bacteria groups:
(1) Gram-positive, G+, (Staphylococcus aureus and Enterococcus faecalis) and (2) Gram-negative, G-, (Pseudomonas
aeruginosa and Klebsiella pneumoniae). The samples under antibacterial testing showed different effective times and
minimum inhibitory concentration (MIC) values. The Gram-negative bacteria showed higher sensitivity to the prepared
samples than Gram-positive bacteria. The combined Cu/Ag vermiculites stopped the bacterial growth at lower MIC value. |