Figure 5 illustrates the absorbance at 405 nm
(Fig. 4) as a function of time. Larger mass percentage
of silver nanoparticles in the NRL membrane increases
the AgNP release speed. Taking the absorbance at
405 nm after 48 h and adopting e(plasmon) = 9.57
L mmol-1 cm-1, as calculated above, we obtained
the total concentration of AgNP released by the NRL
membranes as: 1.4 9 10-5, 4.5 9 10-5, and 3.34 9
10-4 mol L-1, for the samples NRL–AgNp_0.1 %,
NRL–AgNp_0.2 %, and NRL–AgNp_0.4 %, respectively.
It is noteworthy that the concentration of silver
calculated for the sample NRL–AgNp_0.4 % may be
underestimated, because of the high absorbance of the
sample. In this condition, the large attenuation of light
inside the highgly concentrated sample can invalidate
the Lambert–Beer law.