Ionosilicas are defined as silica based materials containing covalently tethered ionic groups. These materials, situated at the interface of silica hybrid materials and ionic liquids, have large potential in catalysis, molecular recognition and separation. This paper focuses on applications of ionosilicas as efficient adsorbents of para-aminosalicylate (PAS). Various ionosilica materials containing ammonium groups were synthesized by template directed hydrolysis-polycondensation reactions starting from silylated precursors, among them one particular material bearing an aromatic benzyl group. The different materials were used for the extraction of PAS from aqueous solution, Specifically, we investigated the sorption process of PAS as a function of the porosity of the material, its chemical constitution, and the pH of the suspension. We further investigated the kinetics and enthalpic displacement effects, based on Isotherm Titration Calorimetry (ITC) measurements. We show that for an identical number of ion exchange sites, PAS is more efficiently adsorbed using an ionosilica bearing aromatic groups. We attribute this result to a pi-pi-stacking contribution involving the phenyl groups of the material, which increases the affinity of PAS towards this particular ionosilica material. In general, our study highlights the high potential of ionosilicas in adsorption processes. Here, ionosilicas with tailored properties can be designed for the separation of specific target compounds. This versatility of these adsorbents will be of interest in advanced separation processes for sustainable development applications.