The antibacterial activity of the textile fabrics coated with
different silver ratios is seen in Tables 3 and 4 against E. coli and
S. aureus, respectively. Tables 3 and 4 show both the change in
antibacterial activity by increasing silver precursor ratio in the first row, and the effect of coating with silver nanoparticles on
antibacterial activity as well as the laundry performance of antibacterial
activity for 30:1 ratio in the second row, against E. coli
and S. aureus, respectively. The clear zones in the areas surrounding
the surface of textile fabrics were observed, while there is no
antibacterial activity around the bare fabrics, Tables 3 and 4. It is
clear that the antibacterial activity is higher against E. coli than S.
aureus for all ratios since there is a wider inhibition zone around
the fabric. To test the permanency of antibacterial activity, the fabric
was washed in an ordinary washing machine using ordinary
detergent. It was observed to decrease the antibacterial activity
against E. coli after the third washing for 10:1 and 20:1 ratios,
whereas the fabric samples with 30:1 ratio still had antibacterial
activity up to five washings. However, significant antibacterial
activity was observed on the surface of fabric against S. aureus
for all ratios even after 20 washings, Table 4. To be able to compare
washing effects, the photos for only 30:1 ratios before and after
washing are given in Tables 3 and 4. During the antibacterial studies,
it was observed that the antibacterial activity was closely
related to wetness of the coated fabrics because of their hydrophobic
surface. Very low and/or no activity was observed when dry
fabrics were tested, which suggests that the mechanism of antibacterial
activity should be based on silver ion release. Thus, silver ion
release from the wet fabrics is higher than from dry fabrics. The
reason for the different antibacterial activity of the textile surfaces
that are produced, against E. coli and S. aureus is another issue to be
investigated.