Creation of a new type of ion exchange material for rapid, high-capacity, reversible and selective ion exchange without swelling and entrainment† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5sc04507j

A new model for ion exchange materials has been proposed on the basis of ion exchange sites grafted to a porous organic polymer.

After the reaction, 6 M HCl (60 mL) was added slowly, and the resulting mixture was stirred for 12 h. The precipitate was collected by filtration, then washed with methanol and water, and dried at 150 °C for 24 h under vacuum (80 mbar) to produce PAF-1 as a white powder, yield: 80%.

The model experiment of extracting MnO4from aqueous solutions
A 50 mL aqueous solution of KMnO4 (10 mg) was added to a 125 mL vial, which was followed by the addition of 25.0 mg samples to form a slurry. During the stirring period, the mixture was filtered at intervals through a 0.45 micron membrane filter for all samples, then the filtrates were analyzed using UV-Vis to determine the concentration of MnO4ions.

Ion exchanged capacity test
The ion-exchange capacity of PAF-1-CH2N + (CH3)3Clwas determined on dry weight basis by a traditional titration method. 9 Typically, 0.5 g PAF-1-CH2N + (CH3)3Clwas S3 suspended in 5 mL DI water. To this suspension, 0.5 g NaNO3 was added and kept stirring for 5 hours. Then, the mixture was titrated by 0.01 M AgNO3 solution with potassium chromate as indicator.
During the stirring period, the mixture was filtered at intervals through a 0.45 micron membrane filter for all samples, then the filtrates were analyzed using ICP-MS to quantify the gold cyanide amount. To obtain the k2 value, the experimental data was fitted with the pseudo-second-order kinetic model using the following equation: where k2 (g mg -1 min -1 ) is the rate constant of pseudo-second-order adsorption, qt (mg g -1 ) is the amount of Au(I) adsorbed at time t (min), and qe (mg g -1 ) is the amount of Au(I) adsorbed at equilibrium. The distribution coefficient Kd is defined as: 10 where Ci is the initial metal ion concentration, Cf is the final equilibrium metal ion concentration, V is the volume of the treated solution [mL], and m is the mass of sorbent used [g].
The mixtures were stirred at room temperature for 3 h, and then were filtered separately through a 0.45 micron membrane filter, and the filtrates were analyzed by using ICP-MS to determine the remaining Au(I) content. Langmuir isotherm equation has been used to analyze the experimental data. The maximum working capacity were calculated based on the following equation: 11 where Ce and qe are Au(I) equilibrium concentrations in the aqueous and the Au(I) uptake S4 amount for 1 g sample, respectively; Q0 is maximum uptake capacity of the adsorbent, and b is the Langmuir adsorption constants related to the free energy of adsorption. The fitting data are shown in Fig. S8 and S9.
Ionic conductivity (S/cm) was calculated using the formula below: where L is the pellet thickness while A is the pellet area in contact with the stainless-steel electrodes. R is the complex impedance obtained from Nyquist plot. The