Adsorption Mechanism for Aniline on the Hypercross-Linked Fiber

A type of novel hypercross-linked fiber adsorbent was obtained by sulfonation and cross-linking reaction of polypropylene fiber grafted styrene-divinylbenzene. The aim of the fiber sulfonation and cross-linking method was to prepare rigid three dimensional networks in the entire fiber and change the ion exchange capacity of fiber. The hypercross-linked fiber adsorbent possesses a principally different structure and could offer new possibility for adsorption, which is characterized by high adsorption capacity for aniline in this paper. A series of static adsorption tests were made. The results showed that the adsorbent has excellent adsorption capacity for aniline and the adsorption equilibrium data can be well fitted by Freundlich model. Adsorption of aniline on adsorbent was chemical adsorption and high temperature was favourable to endothermic chemisorption process. In addition, the kinetic studies were also carried out. The hypercross-linked fiber adsorbent showed faster adsorption rate than the base fiber. The quicker attainment of adsorption equilibrium (within 20 minutes) for aniline on adsorbent is advantageous for practical use. The pseudo-second-order rate model was suitable to describe the process. The pseudo-second-order model gave an excellent fit to all experimental data and adsorption capacities calculated by pseudo-second-order rate model were close to the values actually measured.