Langmuir and Freundlich absorption models were used to perform
absorption capacity analyses. The experimental results were fitted to
the models and the most appropriate model was determined and
then used to estimate the maximum amount of absorption associated
with MCM-41 and S-MCM. The models are defined as follows.
2.5.1. Freundlich Isotherm Absorption Theory
Q ¼ KCo
1=n ð1Þ
Taking the natural logarithm of both sides gives:
lnQ ¼ lnK þ 1
n
lnCo ð Þ ð2Þ
where Co is the initial concentration and Q is the amount of toluene
adsorbed by the additive. If the experimental adsorption matches