2.3.4. Light transmission and transparency
The ultraviolet (UV) and visible light transmission of the filmswere quantified at selected wavelengths between 200 and 800 nm,using a UV-1650 spectrophotometer (Model PC, Shimadzu, Kyoto,Japan). Film strips of 10 ×
40 mm were placed in a spectrophotome-ter test cell. Transparency of the films was determined as in the Eq.(3) (Han and Floros, 1997):
Transparency = A600 x (3)where A600is the absorbance at 600 nm, and x is the film thickness(mm). The greater transparency value shows the lower trans-parency.