Transparency of film determined by transmittance was affected
greatly on the clay types used.
The transmittance decreased significantly (P < 0.05) after incorporation of nanoclay (Table 1) and the
degree of decrease in the transmittance was strongly dependent on
the clay types used.
A possible explanation for the different effect
of clay types on the transmittance of the composite films may be
due to the lipid moieties of quarternary ammonium salts incorporated
in the organoclays (Hong and Rhim 2008).
In addition,the difference in the transmittance of the agar films may be due
to the different miscibility between clay and polymer matrix.
In that sense, Cloisite Na+ seems to be more compatible with agar
compared with other types of clay.
Generally, it is known that the
optical property of awell-developed nanocomposite film is not significantly
changed when the clay platelets with about 1 nm thick
are well dispersed through the polymer matrix, since such clay
platelets with sizes less than the wavelength of visible light do not
hinder light’s passage (Ogata and others 1997).