2.2. Preparation of the magnetic PMADETA/PDVB IPNs
Scheme 1. Synthetic procedure of the magnetic PMADETA/PDVB IPNs.Figure optionsDownload full-size imageDownload as PowerPoint slide
2.3. Characterization of the magnetic PMADETA/PDVB IPNs
FT-IR spectra of the IPNs were recorded on a Nicolet 510P Fourier transform infrared instrument in 500–4000 cm−1 with a resolution of 1.0 cm−1. The BET surface area, pore volume, and pore diameter distribution of the IPNs were determined by N2 adsorption isotherms at 77 K using a Micromeritics Tristar 3000 surface area and porosity analyzer. The morphology of the IPNs was observed using transmission ARRY-142886 microscopy (TEM, JEM-2100F, JEOL, Japan). The magnetization curves of the IPNs were measured by a vibrating sample magnetometer (VSM, Lakeshore 7307) at 300 K.
2.4. Adsorption isotherms
About 0.1000 g of the IPNs was mixed with a series of salicylic acid aqueous solutions with the initial concentration of 196.8, 393.6, 590.4, 787.2 and 984.0 mg/L, respectively. The series of solutions were then shaken in a thermostatic oscillator at a preset temperature (298, 308 or 318 K) and an agitation speed of 200 rpm. The absorbency of salicylic acid adsorbed by the IPNs was analyzed via a UV-2450 spectrophotometer at a wavelength of 296.0 nm, the equilibrium concentration of salicylic acid Ce (mg/L) was determined and the equilibrium adsorption capacity qe (mg/g) was calculated as:equation(1)qe=(C0-Ce)·V/Wqe=(C0-Ce)·V/Wwhere C0 was the initial concentration of salicylic acid (mg/L), V was the volume of the solution (L) and W was the mass of the IPNs (g).