Fig. 7a and Fig. 7b show the speed effect on the absorption spectra of R 101 film samples at 10-4 M for one and two layers, respectively. The absorption spectra of R 101 samples for both one
and two layers, as well as for all spinning speeds show relatively broad spectra. This may be
attributed to the aggregation and dimer formation of R101 dye molecules inside the Xerogel film
host as a result of the heavy molecular weight and the large size of the dye molecule (see Fig. 2), which yields non Newtonian liquid