In order to evaluate the adsorption effect of the two sorbents HM-IMs-5 and HM-NIMs-5 for the template BF, the adsorption capacities of them in BF solutions with different initial concentrations were detected as equilibrium data of adsorption experiments and the curves PD153035 illustrated in Fig. 7b. Furthermore, the equilibrium data were fitted by two common isotherm models Langmuir [40] and Freundlich [41], which are also shown in Fig. 7b. The nonlinear equations of the two isotherm models are expressed as follows:equation(11)Qe=KLQmCe1+KLCeequation(12)Qe=KFCe1/nwhere Qm (μmol g−1) and KL (L μmol−1) are the Langmuir constants related to the adsorption capacity and rate of adsorption. KF (μmol g−1) and n represent the Freundlich constant. 1/n is a measure of the exchange intensity or surface heterogeneity, with a value of 1/n smaller than 1.0 describing a favorable removal condition [42]. In order to predict the favorability of an adsorption system, the affinity constant RL can be defined as follows [43]:equation(13)RL=11+CmKLwhere Cm is the maximal initial concentration of BF. RL indicates the favorability and the capacity of adsorption system. When 0 < RL < 1.0, pleura represents good adsorption. The calculated parameters along with the correlation coefficient (R2) of the two models are listed in Table 3.